Breaking up the giraffe monotony with my next subject (too long postponed in my research): how awesome crocodile anatomy (and locomotion) is! Just a teaser, using a CT scan of one of my favourite freezer specimens: the enigmatic Crocodylus moreletii. The frozen specimen itself was quite rotten so I won’t put a pic of that up right now (you’re welcome!) but the skeletal anatomy shows up great when all that decay is made transparent– and when the bones are turned a pleasing purple.

The specimen came from La Ferme Aux Crocodiles in France, which very kindly let us drive down there and come back with a vanload of >20 awesome crocs, which now occupy the left side of The Freezer.

Edit: check out the great blog post by Darren Naish on Tetrapod Zoology, about a crocodile dissection and crocodylomorph phylogeny- hopefully the start of a long series on these wonderful critters!

Birds and crocodiles are part of the spectacularly diverse group of animals called the Archosauria, or archosaurs if you’re on casual terms with them. Other (extinct) archosaurs include the dinosaurs (non-avian), pterosaurs, and sundry wondrous other beasts like aetosaurs and phytosaurs. Archosaurs have, and presumably their common ancestor had, many specialized features of their anatomy that are related to metabolism and locomotion. That’s a big reason why, as a scientist, I love them.

Yet the bird lineage evolved its own extreme specializations, whereas in some (but not all!) ways crocodilians stayed closer to the ancestral state. Here is a great example of one of the major categories of differences between living crocs and birds: the proportions of the respiratory system, from freezer specimens I’ve CT scanned with my former PhD student Vivian Allen, which were part of a paper we published in Anatomical Record back in 2009. We scanned the thawed specimens with and without the lungs inflated (croc results not shown for inflated state). This was easy; we just stuck a syringe into the windpipe and then tied it off once we had pressurized the lungs. [I'm now working with Colleen Farmer and Emma Schachner on using these specimens to learn more about the surprisingly "bird-like" features of croc lungs despite the smaller total volume of the airways; more about that another day... we can do MUCH better than these images!]

Here, the airways are coloured blue/purple and the flesh has been made transparent yellow, while the skeleton is orange. The relatively massive size of the airways is evident in birds, especially the air sacs (side pockets of the lungs/other air passages), whether they are relaxed or inflated. The lungs (purple) aren’t that differently sized in the two animals.

Australian Freshwater crocodile from CT scan:

Junglefowl (“ancestral wild chicken”) from CT scan; relaxed airways:

Junglefowl from CT scan; inflated airways:

(note that the light blue region is the expanded air sacs; the lung in purple hardly changes because it is fairly rigid in birds)

I’m off soon for a sunny break on the beaches of Morocco, but as an Easter gift to you, my (admirable, sagely, few, beautiful) readers, here is an image of two specimens, formerly from my freezers, to consider:

Both are the right pelvis (hip bones; crocodile pelvis is a bit broken toward the bottom) and femur (thigh bones) of living archosaurs– a 27kg emu above, and a 278kg nile crocodile below. The head would be toward the right side of the picture. A tenfold difference in mass between the bird and the crocodile, and yet some of the dimensions are so similar in both of them (femur length etc.), or so vastly different in the bipedal runner vs. the quadrupedal not-so-fast-runner (much bigger pelvis for leg muscle attachments in the former).

This image says it all. It is why I study the evolution of locomotion in land animals. It is why I am so fascinated by the transition from vaguely crocodile-like early archosaurs to modern birds by way of earlier dinosaurs. Anatomy, size, mechanics, behaviour, phylogeny… the photo captures all the facets of why I am so enraptured by research in this field.

It also might evoke thoughts of what features are expected in a terrestrial vs. aquatic animal, and thoughts of how some numbskulls still think big dinosaurs lived in the water (no I will not link to the execrable story from BBC today that I am thinking of!)…

I hope you appreciate it, too. Have a freezer-burn-free holiday period, folks!

There’s no better way to kick things off after a holiday than with a celebration of the Inside Nature’s Giants series, which I had a small part in early on, including these shots I took during the time they spent filming at the RVC >3 years ago (!?!?); most of these animals spent multiple holidays inside The Freezers:

Elephant arriving...

Elephant revealed

Private moment with elephant

Stunning emergence of The Guts

So you are impressed by the guts too, ehh? It was pretty amazing to watch it happen. The tension was intense- the animal had been dead for a while and was rather bloated. So cutting it open was a task gingerly taken…

Bloated elephant

RVC dissector Richard Prior stuck a scalpel in the upper abdomen when the time was right… the piercing whistle and the sulphuric odour silenced the crowd watching… and then quickly out came the guts.

Everyone was pretty amazed by the scale.

The guts just went on and on...

Not a 1-person job by any means.

Spreading them out to see the whole GI tract.

I waited patiently and watched the show filming; what a great, professional crew. Then I got to take the legs away for our research.

But not just elephants, no sirree! The Windfall Films/ING team filmed giraffe, crocodile and big cats episodes (4 total) at the RVC too; a crazy period of a few weeks (including a major blizzard that hit us during the croc filming) in 2009. Some of the stars follow:

Frozen lion waiting for CT scan, shot 1

Frozen lion waiting for CT scan, leg shot

Frozen lion waiting for CT scan, shot 2; eerily contorted pose

Frozen tiger waiting for CT scan, shot 1

Frozen tiger waiting for CT scan, shot 2

Frozen tiger waiting for CT scan, shot 3

…and here is the tiger’s head after scanning

…and I’m rather fond of that tiger’s neck– check out the hyoids (roaring/tongue apparatus in throat; bottom of movie)!

…and here is the adult Nile crocodile’s head after scanning

…and another view of that big Nile croc, just because I like how this reconstruction turned out

...and here's one of the small (~1m long, 10kg) juvenile Nile crocodiles from the show, with a pilot CT scan showing the skeleton nicely- and possibly a last meal or stomach stone on the left side of the abdomen (bright white blob; I need to check this now that we've dissected it)

Foetal giraffe; stillborn; from the show, in process of dissection in our lab to measure its limb anatomy. Trust me, it looked --and smelled-- better on the inside than it did from the outside. Eew.

How most of the specimens from the first 4 episodes ended up after all dissection was done (part of my/RVC's collection of skeletons). Sadly, I did not get great photos of the 3.7m Nile crocodile or the two giraffes before they were reduced to bits, but I do have the skeletons and CT scans.

Giving a tour (including The Freezers) to A Certain Esteemed Visitor.

(Another) Gratuitous shot with one of the sweet old Red Kangaroos at Alma Park Zoo near Brisbane, Australia. Experiments on hopping we did there will be briefly featured in the new Inside Nature's Giants show on Channel 4, 16 April @2000- details at http://t.co/SkjsMeVC.

Party time! Let the media onslaught begin! We’ve published a paper in Nature on the limb motions of Ichthyostega (and by implication, some other stem tetrapods). Since we did use some crocodile specimens from Freezersaurus (see below) in this study, I figured WIJF could cover it to help celebrate this auspicious event. Briefly. Particularly since we already did a quasi-blog on it, which is here:

http://www.rvc.ac.uk/SML/Research/Stories/TetrapodLimbMotion.cfm

and some juicy fossily images at:

http://www.rvc.ac.uk/SML/Research/Stories/TetrapodImages.cfm

However I want to feature our rockin’ cool animations we did for the paper, to squeeze every last possible drop of science communicationy goodness out of them. So here they are in all their digital glory. Huge credit to Dr. Stephanie Pierce, the brilliant, hardworking postdoc who spearheaded the work including these videos! Dr. Jenny Clack is our coauthor on this study and the sage of Ichthyostega and its relatives- her website is here. Also, a big hurrah for our goddess of artsy science, Julia Molnar, who helped with the videos and other images. Enjoy!

The computer model

The forelimb model

The hindlimb model

We used some of my Nile crocodile collection to do a validation analysis of our joint range of motion (ROM) methods, detailed in the Supplementary info of the paper, which I encourage anyone interested to read since it has loads more interesting stuff and cool pics. We found that a bone-based ROM will always give you a greater ROM than an intact fleshy limb-based ROM. In other words, muscles and ligaments (and articular cartilage, etc.). have a net effect of reducing how far a joint can move. This is not shocking but few studies have ever truly quantitatively checked this with empirical data from whole animals. It is an important consideration for all vert paleo types. Here is a pic of one of the crocodiles from the study, with (A) and without muscles (B; ligaments only):

I’ll close with Julia Molnar’s jaw-droppingly awesome flesh reconstruction from our model. Why Nature wouldn’t use this as a cover pic, I’ll never understand, but I LOVE it! When I first saw it enter my email inbox and then opened it to behold its glory, my squeal of geeky joy was deafening.

(edit: Aha! Fellow Berkeley alum Nick Pyenson’s group made the Nature cover, for their kickass study of rorqual whale anatomy, including a “new” organ! Well, we don’t feel so bad then. Great science– and a win for anatomy!!!)

Title is so meta?

OK Londoners, and Olympics visitors, and anatomy (or just science/biology) buffs, and those not lucky enough to see other versions of the animal Body Worlds show. You have a mission. And that mission is to go see “Animal Inside Out”, a special (£9 for adults is well worth it!) exhbit at the Natural History Museum, open until September 16. This blog will self destruct, very messily, by turning itself inside out in 5 seconds… Boom.

Hippopotamus attempting to outdo elephant guts.

Anatomy to me is beautiful even when it’s “ugly” (messy, wet, mucosal, intestinal, asymmetrical, unlike human, whatever), and that’s a major theme of this blog. Hence I am embarrassed that I hadn’t yet gone to see this Body Worlds spinoff exhibit until now, but can begin to shake off that shame by means of an almost exclusively effusive gushing of blood love for said exhibit. Wow, wow, wow! I went in with no particular expectations, having seen some pictures and knowing some of what to expect, and having other things on my mind. I came out very pleased; the NHM exhibits folks and von Hagens’s crew have created an inspirational spectacle that could do wonders for anatomical sciences and natural history. More about that at the end.

(Warning: possibility of spoilers, but the exhibit is so visual that I don’t think my descriptions can spoil it)

The entrance

No photos are allowed as usual, so all I have to show you is the entrance and some anatomy pics I’ve interspersed from my team’s research to lighten up the text. I suppose I could have asked for special permission to take photos for review usage but this was a very impromptu visit, and with ~4 months of showing left I may well be back again.

Weighing a hippo; spot on at 1600 kg!

There is a brief panel on homology and why it is the major concept underlying comparative anatomy (and a key part of evolution, co-opted from the not-so-evolutionary ideas of Sir Richard Owen, whom the NHM rightly mentions here). Another panel rightly brings up the issue of ethics, which has plagued Body Worlds before. It comforts the visitors that animals were not slaughtered just for this display and that the NHM applied its strict collections criteria to them. Convincing enough for me, and absolutely necessary to bring up early on.

The entry hall then presents you with about five cephalopods (labelled “squid” and “octopus”—a gripe is that species names/details are not given for most specimens on show) prominently occupying the view. The cephalopods, like basically everything else, are plastinated (by a now US-patented set of procedures, I learned from the exhibit book detailed later). They are stunningly frozen in lifelike poses or with gaping cuts to show their interior anatomy, although there was very little explanation here about cephalopod biology and anatomy (about 1 smallish panel). No mention of Cthulhu. Damn. He’d approve of the Grand Guignol scenery.

Toward the back of the first corridor of specimens and cases, there is a stunning scarlet haze outlining the body of a “shark” (species not given) with its huge liver lying below it. The haze, a technique used repeatedly throughout the exhibit, is some kind of corrosion cast of the circulatory system, I gather. A bunch of cross/longitudinal sections of cephalopods, crocodiles, fish, horse hooves and other animals decorate blank spaces on the walls, some with labels showing basic features and some just hung like paintings. Fair enough, but a missed opportunity for a bit more educational content here.

Gratuitious Melanosuchus (black caiman) shot.

A smallish whole shark confronts you as you turn the corner from the crimson chondrichthyan; again of unknown classification. One would think a museum exhibit would care about classification beyond “shark,” but oh well, I am banging the same drum here too much and missing the point, that the exhibit is really a visual, visceral expose rather than a deep prose-driven intellectual dissection. On one of the shark panels it is noted that sharks have red and white kinds of muscle used for slower and faster swimming, but not clarified that this is a very widespread vertebrate (chordate?) feature. This forms my second gripe, that a truly evolutionary approach, such as that taken by dozens of the museum’s research staff as their major paradigm of phylogenetic systematics, could have helped the public grasp the evolutionary, hierarchical nature of homology and depart with accurate information about what features characterize groups at which levels. I’m not asking for cladograms laid out on the floor as at the American Museum of Natural History, although maybe that could work, but the exhibit tended to fall back on an outmoded “this animal has this feature, and that animal has that feature, and these are cool adaptations” shopping list approach rather than a modern comparative approach. Granted, almost all museum exhibits fall into this trap, for various reasons and some of them justified. But with a spare word or phrase here or there, this could have been done better without drowning the visitors in that dreaded sea of bloodprose.

Passing the sharks, we come to one of several thematic sections about body systems, this first one on the skeleton (later, brain/nerves, circulation, muscles, etc.). A few small skeletal specimens of the type that are seen throughout the museum are presented, with a scallop reminding us that skeletons can come in many types among multicellular organisms. There is a horse skull and a stark white whole skeleton of a young-ish ostrich, which was very nicely mounted. However, I was caught off guard by the pelvis, which lacked the curved, ventral “boot” like connection of the pubic bones that ostriches have—presumably explained by its juvenile status although I wasn’t 100% sure it was even an ostrich pelvis. OK, I am having a serious pelvis-nerd moment here; forgive me as my PhD was on this stuff.

Ostrich in the midst of disassembling.

BUT, once again the small interpretive panel had a moment of Fail. The ostrich was explained to have two toes, in contrast to normal birds which have “five”.  HUH? Birds have three main toes and variably also a fourth, inner (first) toe called the hallux, used for perching and other activities including walking. None have a fifth toe; indeed their dinosaurian forebears lost that feature some 230ish million years ago. Just an embryonic vestige of the base of the fifth toe is visible in bird embryos today. Furthermore, the panel said that two toes in ostriches can grip the ground more strongly than more toes in other birds. I know of no evidence that shows this, and suspect that the contrary might be true. The standard explanation for toe reduction in ostriches is that it is a lightening feature characteristic of “cursorial” (long-legged, sometimes fleet/efficient) animals, to make swinging the long legs easier. These errors really should have been caught by involving experts in polishing the scientific content of the exhibit.

But I don’t want this post to grumble too much; wrong message. There was so much to celebrate in this exhibit, which was felt impressively spacious and full of cool specimens! Visitors pass some plastinated whole sheep and goats, with panels nicely explaining that goats and sheep look quite similar on the inside and are evolutionary relatives. Having “four stomachs” (technically, a four-chambered stomach; not four distinct organs that were duplicated) is attributed as a sheep trait, then being a ruminant is said to be a goat trait; this might get a little confusing for non—anatomists (both are ruminants and have similar stomachs).

I learned that goats have an extra tail muscle that allows them to swing up/down as well as side-to-side. Hey, I teach veterinary anatomy and I don’t know that!? I must tuck my tail between my legs in shame, but I am no goat so I do not think I can (do satyrs count?). But I wasn’t so sure that goats, as described, were the first animals to be domesticated—I thought that was dogs? Ahh, Wikipedia says dogs, then sheep, then pigs, then goats? I’m outside my expertise here, I admit, and resorting to Wikipedia out of ignorant desperation. Anyway, here, another instance of coulda-been-more-phylogenetically-specific presented itself: the forelimb of goats was said to be connected to the thorax by muscles and ligaments, not a joint, but this is a feature common to most Mammalia. Although audience attentions might be wandering at this point, waiting for the next big spectacle (goats and sheep are not a big crowd draw, even plastinated), some more care as to what was written would be good. Some reindeer and horses and other animals join in the fun later on. Good, but mostly ‘filler’ (wise to put these in the middle of the exhibit, after sharks/cephalopods and before climax) unless you’re a big fan of fairly familiar ungulates with fairly homogeneous postcrania. OK, my bias is showing…

Gratuitious image of emu curled up for CT scan.

Next along the path, a longitudinal section of a whole ostrich caught my attention. Wow again! I had no idea that one could make a section like this of such a large animal, all in one plastic sheet like a giant microscope slide! I stared at this for a while, wondering how both legs could be fit in a ~1cm thick panel, and gave up trying to understand the technology. Von Hagens, you got me there; I’m stumped. Were multiple sections glued together somehow to produce a pseudo-2D slice from many thin 3D sections? I could not tell, and felt humbled and deeply impressed by the technical skill shown in the exhibits so far…

And then the punches kept coming, one-two-three! The exhibit approaches its climax with a crescendo of great specimens in the final hall. First, another maroon marvel. A whole ostrich, standing with wings askew, showing off its entire circulatory system (plus a few wing plumes for aesthetics) from head to toes! Gorgeous, technically brilliant, and well worth at least a 5 minute walk around (you can stroll around many of the displays in 360 degrees- very good move!). A plastinated whole ostrich stands next to it, and for a muscular anatomy geek like me, it was nirvana. However, in a churlish moment I had to look away from a panel explaining that an ostrich is “too heavy to fly” (I admit some younger visitors may need reminding of this). But then I looked into the big open space of this main hall, and the climax was before me. I think I’d had my climax a few times since this, but wow this was enormous in so many ways. All the ways. Mind-blowingly, vastly, geektastically kewl.

Gratuitious rhinoceros leg.

Across from the two posed ostriches and flanked by numerous smaller specimens, the elephant and giraffe stand frozen in vigil. There is also a lovingly detailed dissection of a huge male gorilla by the back wall and exit, with a panel reminding us that gorillas are (among) “our closest relatives.” The giraffe is precariously poised on one front toe-tip, in mid-gallop. What a great pose! There is the requisite explanation of how they solve the blood pressure problem in their neck (e.g. arterial valves), but also the statement, news to me, that they are the only animals able to ruminate while running. Who figured that out and how? I really want to know! Must be hard to check. (or was walking intended? Are my notes wrong?) Across from the full-fleshed plastinated giraffe (which I could see with my eyes closed after all our dissections from a month ago), there was another visually arresting and technically monumental giraffe on exhibit: one represented completely by small, reddish cross-sectional slices, from head to toes in a standing pose. That took me a while to absorb, it was so lovely, almost like a hanging mobile of morphological splendour.

There is a panel about genes and variation and inheritance. It is brief. (and it belongs there) Thank you. Let’s celebrate anatomy for anatomy’s sake for once!

“But John,” you might say, “What about the elephant? No love for the elephant? The star of the show?”

Zoinks! I want one! Stoic and triumphant (except against death and plastination), the Asian elephant is the centrepiece of the collection. (The book explains it was “Samba” from Neunkirchen Zoo, Germany, dead of some circulatory problem in 2005 and the first one plastinated, plus the inspiration for the animal show). I was speechless and paralyzed for a moment. I didn’t even know how to start looking at the partly-exploded-to-show-its-insides elephant. I actually avoided it for a while, looking closely at the other specimens, and building up anticipation, before stepping up and taking a long, intense look at this tall drink of water.

Go see the elephant. If you know basic anatomy, look at its leg muscles. Check out the huge triceps, still attached to the elbow; I like to say it is the size of a graduate student. Same for the analogous superficial gluteal and somewhat-fused biceps femoris muscles on the rear end, around the thigh/knee joint. Huge! I’ve never been able to view a standing dissected elephant, so this really impressed me more than a table full of giant muscle slabs like I normally deal with. And best of all, for me, the “false sixth toes”; the prepollex and prehallux; are visible in all four feet (but not noted anywhere, even in the book; too bad, these things were widely known by anatomists before my work on them). So much to marvel at here. It is an anatomical treasure. I wish I had a 3D image of it to use for anatomical studies- it was so easy to identify every single muscle group (except for a few missing around the shoulder/neck), even in the distal limbs. Hmm, photogrammetry might be possible (nugget of idea begins to crawl around John’s brain like a Zimmerian parasite)…

Behold, the triceps muscle of an elephant!

Behind that gorgeous elephant, don’t miss the wall mountings of two cross-sectional slices: through the head/neck of a moderate-sized elephant (How!?!?) and distal leg (no predigits but good features). And definitely don’t miss the stool (non-fecal, furniture form). I almost did. A wooden stool is shaped like a newborn elephant and a cross-section of the body is adhered on top of it. I assume you cannot sit there, and I am very glad that it was not, as I first imagined, an actual plastinated baby elephant turned into a stool. That would be bad taste.

The exhibit is in very good taste, without exception, and although I am gore-desensitized to say the least, it is not gory in my view. The plastination process preserves the reality and even some of the colour faithfully, but renders it just unreal enough (past uncanny valley territory?) that it should not be very disturbing to most viewers.

You can’t leave with your own photographs, but you can be schnookered into buying the exhibit book (£12.99) and a couple of packages of nice colour postcards (£4 for six; excellent quality images and cardstock IMO). The book and postcards show many of the exhibit specimens but not all, and include some others that are not on exhibit. I was saddened that the bear was left out—very cool image of that in the book. I’ve only skimmed the book a bit. I was annoyed by a few mistruths about elephants (25mph running speed, “have no ankle joints, which is one of the reasons why elephants cannot jump”, the bones “do not contain any marrow”—wrong, 15mph and there are ankles, they just are not very flexible (but not immobile either); also the bones do contain marrow (how could a large vertebrate survive entirely without it???) but just not as much of it per unit volume, due to lots of spongy bone). But I am still very happy with the 139 pages chock fulla pretty images, which is all I really wanted. Indeed, the book is a great pictorial anatomical reference- some of the species such as elephants and giraffe lack a really good anatomical resource in the modern, or any, literature! The exhibit shop also sells some good anatomy texts, mostly on humans but I recommend “Animal Anatomy for Artists” very strongly; I use that regularly in my own work.

So, £29.99 of schnookering later (haha, poor victimized me!), I emerged and reflected more on what I’d seen. I’m still a bit giddy about it all. I like the minimalism in most aspects- black backgrounds, minimal signage (but just enough to make it educational—when they got the facts right), focus kept on the specimens. Well done there. The spectacle of the specimens I’ve raved plenty about- it is not at all disappointing. It is AWESOME in every sense. I feel I easily got £9 of value from the ticket, and would (probably will!) pay it again. It is a profound experience to see the rich anatomical detail exposed, and be able to circumnavigate the specimens to absorb multiple perspectives. If you know some anatomy, you’ll be doubly rewarded at least, and if you bring your own phylogenetic perspective that can be trebled.

Baby white rhinoceros. Sad infant mortality.

What makes me happiest after my visit is realizing that we are in an anatomical renaissance for science and public interest therein. Exhibits like this and documentaries like “Inside Nature’s Giants” have tapped a public interest and curiosity in the wonders of basic anatomy. Anatomy is at the core of so many biological sciences and is so immediately accessible to people, because we all have anatomy. Anatomy is at the crossroads of art and science; it is visual, variable and complex, yet concrete, objective and easy to relate to. “Animal Inside Out” is a spectacular blend of art and science. They nail the artistic aspect, and the science is done reasonably well (despite my few gripes)—the exhibit’s science speaks for itself, in a way, although many visitors will need a nudge to grasp that.

I’d like to make a call for a permanent exhibit of the likes of “Animal Inside Out” in the UK. We deserve this! Museum exhibits could use something new, other than lame, quickly broken digital pushbuttons and bland skeletons devoid of soft tissue context (although the latter can be sufficient, e.g. at the Paris NMNH). That’s what makes “Animal Inside Out” (and Body Worlds) such a hit- as Hagens is quoted on the book dustcover, animal anatomy that goes beyond digitized abstractions and dusty bones is able “to sharpen our sense of the extraordinary by looking at the self-evident.” I could not say it better myself. This exhibit is extraordinary; that is self-evident after even a peek. It is a loving tribute to how fantastic the totality of animal structure is. Go! Enjoy. Absorb. Gape. Stare. Thrill. Revel. Think. Question. IT’S BEAUTIFUL.

Impressive hippo mouth says “Farewell for now.”

Edit: @samjamespearson on Twitter has kindly posted some photos (for free NHM/AIO publicity) of the exhibits and here are the links, now that they’re out there– SPOILERS! And thanks, Sam! I don’t think these really spoil the intense visual experience of actually being there and walking around the specimens, not at all.

octopus, whelk, squid, needlefish, scarlet haze of shark, hare brain, cat nerves,  bactrian camel, another camel,  bull (I forgot to mention it; this one was pretty great!)

I stumbled across some old pics, which I thought I’d lost, from the filming/preparations of 4 episodes of Inside Nature’s Giants (Jan-Feb 2009) at the RVC. They form a nice accompaniment to my previous post reflecting on my experience with the show, and the timing is great because I’m about to head to Raleigh, NC to talk about this research at the Society for Vertebrate Paleontology conference.

Stomach-Churning Rating: 4 at first (just a dead animal; and a rather clean one at that), then about halfway through the dissections start and it edges up to a 7 or so.

These pictures are sadly some of the few I have of the whole, intact body of a gorgeous adult Nile crocodile (Crocodylus niloticus) that the Windfall Films team managed to get to the RVC from La Ferme Aux Crocodiles in Pierrelatte, France. (I have scores of pics of the dissected limbs, shown further below) As the title indicates, it was a nice big croc. And as you’d expect, CT scanning and then dissecting it was no tiny feat, and makes a fun story. Story time, then, after an introductory pic!

Dr Samuel Martin, vet from La Ferme Aux Crocodiles, brought the crocodile (and some smaller specimens) over to our Hawkshead campus in late January 2009, and we quickly moved to run the specimen through our CT scanner to preserve some details of its anatomy (example shown at the end of this post) and for potential usage in the show. As the photos below illustrate, this was hard work for several people.

And then, as we were finishing the last CT scans of the specimen, our ageing medical scanner stopped working. And could not be resuscitated. R.I.P., Picker PQ5000 (buy one or two here!). The crocodile, “WCROC” as my team came to designate it, had claimed its final victim. It took about a year for us to get a new one, and that year sucked. It made me appreciate how lucky we are to have a CT scanner just across the parking lot from my office!

Anyway, the day of filming I was hoping to make it in to watch my colleague and friend Dr Greg Erickson help lead the dissection team, but a wicked blizzard blew up, and as I was starting the 31 mile drive south from my home to the RVC I realized, from the queue of cars that seemed to be 31 miles long (and train lines shut down), that this was going to be a snow day. So I turned around and came home. Another victory for WCROC!

The filming proceeded despite heavy snow delaying many of the key players’ arrivals. I got filmed a day or two later for a little section of the show on the limbs and locomotion of crocodiles but sadly this got cut from the main ING show (but did air in the National Geographic version “Raw Anatomy“, in the USA at least).

The limbs had been left largely intact, although some of the dissectors who didn’t know croc anatomy very well had slashed through parts of the pelvis and, in eagerness to reach key parts to demonstrate in the show, some major muscles got shredded. This is no big surprise; crocodiles have a lot of bones all over the place: in their skin (scutes; bony armour), in their bellies (the belly ribs called gastralia), and almost everywhere else, so some brute force is required to get to the gooey bits. Apparently there had been 6 or so people dissecting at once and things got a little carried away. The curse of WCROC continues?

Oh well; that’s just how documentaries go sometimes, especially with a pioneering show like this and the intensely compressed timescales of filming (time is ££!). There can be pulses of chaos. And the show turned out GREAT! (alternative link if latter does not work outside UK)

Let’s have more photos tell the story of the scanning, which also shows off this beautiful animal’s external anatomy:

Anyway, things turned out fine overall for our research. A week or so later (maybe longer; I forget if the specimen was frozen and thawed out for us) we came in to start dissections. We were really excited to measure the limb muscles of such a big crocodile, for comparison to a growth series (babies to adults) of alligators that my former PhD student (now postdoc; Dr.) Vivian Allen had dissected back in 2008. Here he is with a masked co-dissector, displaying their joy for the task at hand:

And let’s not leave out the exhuberance of visiting research fellow Dr. Shin-Ichi Fujiwara! He wanted to inspect the forelimbs for his ongoing studies of limb posture, joint cartilages and locomotor mechanics.

The remaining images show progressive stages of dissection of WCROC, starting from the pectoral (fore-) limbs with a view of the belly (and the giant jaw-closing muscles visible on the left side of image):

Isolated right forelimb, with coracoid (part of shoulder girdle) sticking through:

Assorted forelimb/upper arm (brachial) muscles:

And the triceps (elbow-straightening) muscles; not that big in such a big animal:

…and on to the pelvic limbs and the huge tail:

With a closer look at the HUGE thigh muscle, the famed M. caudofemoralis longus:

And then an isolated right hindlimb:

Thigh muscles, with which I have a peculiar fascination that stems from my PhD research:

And last, the great, paddle-like hind foot!

What a great experience that was! We have fond memories of WCROC, a great documentary from Windfall Films, some nice data– and a lovely skeleton. Perhaps the curse of WCROC is not so bad. Nothing can go wrong now!

Soon Mieke Roth, scientific illustrator from the Netherlands, is coming here to do a similar dissection on more Nile crocodiles at the RVC. As with the octopus she wrote about in September, she will make a 3D model, but with much more detail and with an emphasis on accuracy and accessibility. The end products will be really cool; think of the visible body, 3d models that can be used in teaching, animations, a book and lots more but also a “how did she do that?” blog. To finance this project (that probably will take a year or more) she will use crowd funding. In several weeks there will be more info on how to participate in her fantastic endeavour. For now, see her video with the initial pitch for “Nile Crocodile 2.0“!

A quick report on an exciting event for my team, from this week: We got a box! A big one! With 10 frozen crocodiles.

Stomach-Churning Rating: 5 out of 10. Just 1 picture with some blood.

These come from a breeding centre in southern France, and died of natural causes. Here is a little, icy box of five Crocodylus moreletii, a species that has featured here before:

And five young Nile crocodiles (remember WCROC?), one of which seems to have had an uncomfortable encounter with a larger relative:

Science shall blossom from their demise.

The end.

Today I’m doing something a bit unusual for this blog, but which very comfortably fits within its theme. Enough talking about my papers and media appearances and such. Too much self-indulgence, I feel. I want to talk about someone else. And then I will get back to the usual business of this blog: sharing the joy of cool anatomy, with a Mystery Dissection/Image post that is long overdue. Yet first, I wish to share the joy of knowing a cool anatomist– and artist.

One of my great shames as a scientist is that I never cultivated some decent artistic skills that I had as a young boy. And now as an anatomist I feel that my work often suffers from a lack of artistic talent (e.g. the image below, which still makes me hang my head in shame). In addition to scientific know-how, anatomy, when done best, demands the eyes and the hands of an artist. I might have the eyes but I definitely lack the hands. I envy people that have both; Julia Molnar from my team is but one example. And for me, encountering them is always a special delight. What follows is my personal perspective on one of the shining stars in the field.

Right ischium (hip bone; pelvis/synsacrum) of an adult ostrich in side view, showing some muscle origins and stuff, with a 1cm scale bar. Cringe. My boring, amateurish, pixelly line drawing from a paper on pelvic evolution. I hate it and wish I’d done better.

Mieke Roth is a scientific illustrator from the Netherlands, with a Masters degree from the prestigious and hallowed halls of Wageningen University.  Her homepage has the tagline “Complex processes beautifully revealed”. This is a wonderfully succinct and eloquent way to describe the magic that she is able to conjure with her skills in scientific illustration. Her “Ultimate Croc Anatomy” project will be the greatest weaving of that sorcery yet. That project is described and will be documented on this page, and has an Indiegogo crowdfunding page here. Mieke describes its goals best:

“I will meticulously dissect a Nile crocodile and document it. I will share the dissection in text, illustrations and video via my website. I will process the data I gathered and each time build a new part of the digital crocodile. From there I will adapt the model for illustrations, books, animations and apps.”

I first became a happy victim of the artistic spells that Mieke casts when I saw her blog entry “How to make an octopus,” which you absolutely must read if you have not already or else you’ll be firmly spanked and sent away from this blog with only lumps of coal in your freezer for Freezermas (what’s Freezermas? Find out soon, and in the meantime be nice– or else!). In her post, Mieke didn’t just look up a picture of an octopus somewhere and redraw it in an abstract, schematic, flat and deceptively simplified way. She went and did her own hands-on research by dissecting an octopus, and then described the steps in converting those observations into a brilliantly novel set of digital illustrations that really brought octopus anatomy to life.

Octopus image by Mieke Roth

Part of what first mesmerized me is that this whole investigative and creative process was lovingly documented on her blog. In doing this, Mieke played the roles of both scientist and artist, by displaying the mundane-but-wonderful labour she did to come up with her final, gorgeous results, and the passion, dedication, scholarship and originality that make her stand head and shoulders above so many gifted scientific or medical illustrators. This thrilled me at both visceral and intellectual levels. It literally gave me chills to witness how good the final product was. As I write this and look back on that blog again, months later, I still feel the magic.

So then I started browsing around her homepage and became punch-drunk from repeated blows of amazement—again and again and again the quality and novelty and thoroughness leaped off the computer screen. Images of nature that I thought I knew well, such as the growth of a chick into a chicken (really great blog here documenting this with sketches), were conveyed in a way that made me see them as if for the first time, with joy and wonder. In the space of a day, I became a huge Mieke Roth fan.

Young chicken sketched by Mieke Roth

And now Mieke is taking it not just a notch, but a huge step, to spend a year documenting the anatomy of the Nile crocodile—how cool is that!?! As an expert in the postcranial anatomy of the Crocodylia, I can confidently state that the available scientific literature on the subject is patchy in coverage and often poor in quality by modern standards. There are big flashes of excellence here and there, such as Larry Witmer’s and Chris Brochu’s teams’ very thorough work on head and neck anatomy, or Colleen Farmer’s and Emma Schachner’s studies of lung morphology. But then I glance at some scholarly books (to avoid offending, I will not cite them here) that are supposed to be key references on the complete anatomy of Crocodylia and I frankly am left cold. While there is some superb work from the 1800s (Gadow, Fürbringer and others come immediately to mind), it is in the flat, often colourless style which the printing technology of that age imposed upon those great masters of anatomy. And while there is superb work by Romer, a tome on the Chinese alligator and a few others, again they tend to be limited to line drawings or spotty coverage of various anatomical systems. We need a visionary with both the scientific and artistic skill to make a subject that could seem dry or arcane become miraculous and accessible. I think you can guess whom I have in mind.

I can think of no one better suited to the ambitious goals and demands of the Ultimate Croc Anatomy project than Mieke Roth. She combines the attention to anatomical detail of a classical 19^th century anatomist with the technical wizardry of a modern digital artist. She will have a supportive team of experts to ensure the content is exceptional and up-to-date. I’ll be one of them (and the crocs will come from my freezer), because of my enthusiasm for  the project, and I’ve been helping to recruit others. So I urge you not just to join in her crowdfunding effort to carry out a very worthy and exciting project that the world can share, but also to share the joy I had in discovering her work by browsing her online collection of awesomeness. I predict that many of you will feel the power of her spell and become Mieke Roth fans, too, if you are not fortunate enough to be one yet.

Squirrel monkey drawing by Mieke Roth

Our 3D computer models of a basal dinosaur and bird, showing methods and key differences in body shape. The numbers at the bottom are museum specimen numbers.

At about the moment I’m posting this, our Nature paper (our more formal page here, and the actual article here) embargo is ending, drawing a 14+ year gestation to a close. The paper is about how dinosaur 3D body shape changed during their evolution, and how that relates to changes in hindlimb posture from early dinosaurs/archosaurs to birds; “morpho-functional evolution” sums up the topic. We used the 3D whole-body computational modelling that I, Allen and Bates (among others) have developed to estimate evolutionary changes in body dimensions, rather than focusing on single specimens or (as in our last study) tyrannosaur ontogeny. We’ve strongly supported the notion (dating back to Gatesy’s seminal 1990 Paleobiology paper) that the centre of mass of dinosaurs shifted forwards during their evolution, and that this shift gradually led to the more crouched (flexed) hind leg posture that characterizes living birds. Here is a movie from our paper showing how we did the modelling:

And here is a summary of our 17 computer models of archosaur bodies, shown as one walks along the tips of the phylogeny shown in the video (the models are not considered to be ancestral to one another; we used a common computer algorithm called squared-change parsimony to estimate ancestral state changes of body dimensions between the 16 numbered nodes of the tree):

But we’ve done much more than just put numbers on conventional wisdom.

We’ve shown, to our own surprise, that the shift of the centre of mass was largely driven by evolutionary enlargements of the forelimbs (and the head and neck, and hindlimbs, to a less strong degree), not the tail as everyone including ourselves has assumed for almost 25 years. And the timing of this shift occurred inside the theropod dinosaur group that is called Maniraptora (or Maniraptoriformes, a slightly larger group), so the change began in animals that were not flying, but not long before flight evolved (depending on whom you ask, what taxonomy they favour and what evidence one accepts, either the smaller clade Eumaniraptora/Paraves or the bird clade Aves/Avialae).

Now, if you don’t like the cliche “rewriting the textbooks”, do have a look through texts on dinosaur/early avian palaeobiology and you probably will find a discussion of how the tail shortened, the centre of mass moved forwards as a consequence, the caudofemoral musculature diminished, and theropod dinosaurs (including birds) became more crouched as a result. We did that to confirm for ourselves that it’s a pretty well-accepted idea. Our study supports a large proportion of that idea’s reasoning, but modifies the emphasis to be on the forelimbs more than the tail for centre of mass effects, so the story gets more complex. The inference about caudofemoral muscles still seems quite sound, however, as is the general trend of increased limb crouching, but out paper approximates the timing of those changes.

Figure 3 from our paper, showing how the centre of mass moved forwards (up the y-axis) as one moves toward living birds (node 16); the funny dip at the end is an anomaly we discuss in the paper.

A final implication of our study is that, because the forelimbs’ size influenced the centre of mass position, and thus influenced the ways the hindlimbs functioned, the forelimbs and hindlimbs are more coupled (via their effects on the centre of mass) than anyone has typically considered. Thus bipedalism and flight in theropods still have some functional coupling– although this is a matter of degree and not black/white, so by no means should we do away with helpful concepts like locomotor modules.

And in addition to doing science that we feel is good, we’ve gone the extra mile and presented all our data (yes, 17 dinosaurs’ worth of 3D whole body graphics!) and the critical software tools needed to replicate our analysis, in the Dryad database (link now working!), which should have now gone live with the paper! It was my first time using that database and it was incredibly easy (about 1 hour of work once we had all the final analysis’s files properly organized)– I strongly recommend others to try it out.

That’s my usual general summary of the paper, but that’s not what this blog article is about. I’ll provide my usual set of links to media coverage of the paper below, too. But the focus here is on the story behind the paper, to put a more personal spin on what it means to me (and my coauthors too). I’ll take a historical approach to explain how the paper evolved.

This paper’s story, with bits from the story of my life:

Embarassing picture of me before I became a scientist. Hardee’s fast food restaurant cashier, my first “real job”, from ~1999- no, wait, more like 1986. The 1980s-style feathered (and non-receding) hair gives it away!

Rewind to 1995. I started my PhD at Berkeley. I planned to use biomechanical methods and evidence to reconstruct how Tyrannosaurus rex moved, and started by synthesizing evidence on the anatomy and evolution of the hindlimb musculature in the whole archosaur group, with a focus on the lineage leading to Tyrannosaurus and to living birds. As my PhD project evolved, I became more interested and experienced in using 3D computational tools in biomechanics, which was my ultimate aim for T. rex.

In 1999, Don Henderson published his mathematical slicing approach to compute 3D body dimensions in extinct animals, which was a huge leap for the field forward beyond statistical estimates or physical toy models, because it represented dinosaurs-as-dinosaurs (not extrapolated reptiles/mammals/whatever) and gave you much more information than just body mass, with a lot of potential to do sensitivity analysis.

I struggled to upgrade my computer skills over the intervening years. I was developing the idea to reconstruct not only the biomechanics of T. rex, but also the evolutionary changes of biomechanics along the whole archosaur lineage to birds– because with a series of models of different species and a working phylogeny, you could do that. To me this was far more interesting than the morphology or function of any one taxon, BUT required you to be able to assess the latter. So Tyrannosaurus became a “case study” for me in how to reconstruct form and function in extinct animals, because it was interesting in its own right (mainly because of its giant size and bipedalism). (Much later, in 2007, I finally finished a collaboration to develop our own software package to do this 3D modelling, with Victor Ng-Thow-Hing and F. Clay Anderson at Honda and Stanford)

Me and a Mystery Scientist (then an undergrad; now a very successful palaeontologist!), measuring up a successful Cretaceous hypercarnivore at the UCMP; from my PhD days at Berkeley, ~2000 or so.

In all this research, I was inspired by not only my thesis committee and others at Berkeley, but also to a HUGE degree by Steve Gatesy, a very influential mentor and role model at Brown University. I owe a lot to him, and in a sense this paper is an homage to his trailblazing research; particularly his 1990 Paleobiology paper.

In 2001, I got the NSF bioinformatics postdoc I badly wanted, to go to the Neuromuscular Biomechanics lab at Stanford and learn the very latest 3D computational methods in biomechanics from Prof. Scott Delp’s team. This was a pivotal moment in my career; I became partly-an-engineer from that experience, and published some papers that I still look back fondly upon. Those papers, and many since (focused on validating and testing the accuracy/reliability of computer models of dinosaurs), set the stage for the present paper, which is one of the ones I’ve dreamed to do since the 1990s. So you may understand my excitement here…

Stanford’s Neuromuscular Biomechanics Lab, just before I left in 2003.

But the new paper is a team effort, and was driven by a very talented and fun then-PhD-student, now postdoc, Dr Vivian Allen. Viv’s PhD (2005-2009ish) was essentially intended to do all the things in biomechanics/evolution that I had run out of time/expertise to do in my PhD and postdoc, in regards to the evolution of dinosaur (especially theropod) locomotor biomechanics. And as I’d hoped, Viv put his own unique spin on the project, proving himself far better than me at writing software code and working with 3D graphics and biomechanical models. He’s now everything that I had hoped I’d become by the end of my postdoc, but didn’t really achieve, and more than that, too. So huge credit goes to Viv for this paper; it would never have happened without him.

We also got Karl Bates, another proven biomechanics/modelling expert, to contribute diverse ideas and data. Furthermore, Zhiheng Li (now at UT-Austin doing a PhD with Dr Julia Clarke) brought some awesome fossil birds (Pengornis and Yixianornis) from the IVPP in Beijing in order to microCT scan them in Londo. Zhiheng thus earned coauthorship on the paper — and I give big thanks to the Royal Society for funding this as an International Joint Project, with Dr Zhonghe Zhou at the IVPP.

That’s the team and the background, and I’ve already given you the punchlines for the paper; these are the primitive and the derived states of the paper. The rest of this post is about what happened behind the scenes. No huge drama or anything, but hard, cautious work and perseverance.

Me shortly after I moved to the RVC; video still frame from a dinosaur exhibit (c. 2004) I was featured in. Embarassingly goofy pic, but I like the blurb at the bottom. It’s all about the evolutionary polarity, baby!

The paper of course got started during Viv’s PhD thesis; it was one of his chapters. However, back then it was just a focus on how the centre of mass changed, and the results for those simple patterns weren’t very different from those we present in the paper. We did spot, as our Nature supplementary information notes,  a strange trend in early theropods (like Dilophosaurus; to a lesser degree Coelophysis too) related to some unusual traits (e.g. a long torso) and suggested that there was a forward shift of centre of mass in these animals, but that wasn’t strongly upheld as we began to write the Nature paper.

On the urging of the PhD exam committee (and later the paper reviewers, too), Viv looked at the contributions of segment (i.e. head, neck, trunk, limbs, tail) mass and centre of mass to the overall whole body centre of mass. And I’m glad he did, since that uncovered the trend we did not expect to find: that the forelimb masses were far more important for moving the centre of mass forwards than the mass (or centre of mass) of the tail was– in other words, the statistical correlation of forelimb mass and centre of mass was strong, whereas changes of tail size didn’t correlate with the centre of mass nearly as much. We scrutinized those results quite carefully, even finding a very annoying bug in the 3D graphics files that required a major re-analysis during peer review (delaying the paper by ~6 months).

The paper was submitted to Nature first, passing a presubmission inquiry to check if the editor felt it fit the journal well enough. We had 3 anonymous peer reviewers; 1 gave extensive, detailed comments in the 3 rounds of review and was very fair and constructive, 1 gave helpful comments on writing style and other aspects of presentation as well as elements of the science, and 1 wasn’t that impressed by the paper’s novelty but wanted lots more species added, to investigate changes within different lineages of maniraptorans (e.g. therizinosaurs, oviraptorosaurs). That third reviewer only reviewed the paper for the first round (AFAIK), so I guess we won them over or else the editor overruled their concerns. We argued that 17 taxa were probably good enough to get the general evolutionary trends that we were after, and that number was ~16 more species than any prior studies had really done.

Above: CT scan reconstruction of the early extinct bird Yixianornis in slab conformation, and then Below: 3D skeletal reconstruction by Julia Molnar, missing just the final head (I find this very funny; Daffy Duck-esque) which we scaled to the fossil’s dimensions from the better data in our Archaeopteryx images. There is also the concern, which the reviewers didn’t focus on but I could see other colleagues worrying about, that some of the specimens we used were either composites, sculpted, or otherwise not based on 100% complete, perfectly intact specimens. The latter are hard to come by for a diversity of extinct animals, especially in the maniraptoran/early bird group. We discussed some of these problems in our 3D Tyrannosaurus paper. The early dinosauromorph Marasuchus that we used was a cast/sculpted NHMUK specimen based on original material, as was our Coelophysis, Microraptor and Archaeopteryx; and our Carnegie ??Caenagnathus?? specimen was based more on measurements from 1 specimen than from direct scans, and there were a few other issues with our other specimens, all detailed in our paper’s Supplementary Information.

But our intuition, based on a lot of time spent with these models and the analysis of their data, is that these anatomical imperfections matter far, far less than the statistical methods that we employed– because we add a lot of flesh (like real animals have!) outside of the skeleton in our method, the precise morphology of the skeleton doesn’t matter much. It’s not like you need the kind of quality of anatomical detail that you need to do systematic analyses or osteological descriptive papers. The broad dimensions can matter, but those tend to be covered by the (overly, we suspect) broad error bars that our study had (see graph above). Hence while anyone could quibble ad infinitum about the accuracy of our skeletal data, I doubt it’s that bad– and it’s still a huge leap beyond previous studies, which did not present quantitative data, did not do comparative studies of multiple species, or did not construct models based on actual 3D skeletons as opposed to artists’ 2D shrinkwrapped reconstructions (the “Greg Paul method”). We also did directly measure the bodies of two extant archosaurs in our paper: a freshwater crocodile and a junglefowl (CT scan of the latter is reconstructed below in 3D).

One thing we still need to do, in future studies, is to look more carefully inside of the bird clade (Aves/Avialae) to see what’s going on there, especially as one moves closer to the crown group (modern birds). We represented modern birds with simply 1 bird: the “wild-type chicken” Red junglefowl, which isn’t drastically different in body shape from other basal modern birds such as a tinamou. Our paper was not about how diversity of body shape and centre of mass evolved within modern birds. But inspecting trends within Palaeognathae would be super interesting, because a lot of locomotor, size and body shape changes evolved therein; ostriches are probably a very, very poor proxy for the size and shape of the most recent common ancestor of all extant birds, for example, even though they seem to be fairly basal within that whole lineage. And, naturally, our study opens up opportunities for anyone to add feathers to our models and investigate aerodynamics, or to apply our methods to other dinosaur/vertebrate/metazoan groups. If the funding gods are kind to us, later this year we will be looking more closely, in particular, at the base of Archosauria and what was happening to locomotor mechanics in Triassic archosaurs…

Clickum to embiggum:

Australian freshwater crocodile, Crocodylus johnstoni; we CT scanned it in 3 pieces while visiting the Witmer lab in Ohio.

A Red junglefowl cockerel, spotted in Lampang, Thailand during one of my elephant gait research excursions there. Svelte, muscular and fast as hell. This photo is here to remind me to TAKE BLOODY PICTURES OF MY ACTUAL RESEARCH SPECIMENS SO I CAN SHOW THEM!

I’d bore you with the statistical intricacies of the paper, but that’s not very fun and it’s not the style of this blog, which is not called “What’s in John’s Software Code?”. Viv really worked his butt off to get the stats right, and we did many rounds of revisions and checking together, in addition to consultations with statistics experts. So I feel we did a good job. See the paper if that kind of thing floats your boat. Someone could find a flaw or alternative method, and if that changed our major conclusions that would be a bummer– but that’s science. We took the plunge and put all of our data online, as noted above, so anyone can do that, and that optimizes the reproducibility of science.

What I hope people do, in particular, is to use the 3D graphics of our paper’s 17 specimen-based archosaur bodies for other things– new and original research, video games, animations, whatever. It has been very satisfying to finally, from fairly early in the paper-writing process onwards, present all of the complex data in an analysis like this so someone else can use it. My past modelling papers have not done this, but I aim to backtrack and bring them up to snuff like this. We couldn’t publish open access in Nature, but we achieved reasonably open data at least, and to me that’s as important. I am really excited at a personal level, and intrigued from a professional standpoint, to see how our data and tools get used. We’ll be posting refinements of our (Matlab software-based) tools, which we’re still finding ways to enhance, as we proceed with future research.

Above: Two of the 17 archosaur 3D models (the skinny “mininal” models; shrinkwrapped for your protection) that you can download and examine and do stuff with! Dilophosaurus on the left; Velociraptor on the right. Maybe you can use these to make a Jurassic Park 4 film that is better, or at least more scientifically accurate, than Hollywood’s version! Just download free software like Meshlab, drop the OBJ files in and go!

Now, to bring the story full circle, the paper is out at last! A 4 year journey from Viv’s PhD thesis to the journal, and for me a ~14 year journey from my mind’s eye to realization. Phew! The real fun begins now, as we see how the paper is received! I hope you like it, and if you work in this area I hope you like the big dataset that comes with it, too. Perhaps more than any other paper I’ve written, because of the long voyage this paper has taken, it has a special place in my heart. I’m proud of it and the work our team did together to produce it. Now it is also yours. And all 3200ish words of this lengthy blog post are, as well!

Last but not least, enjoy the wonderful digital painting that Luis Rey did for this paper (another of my team’s many failed attempts to get on the cover of a journal!); he has now blogged about it, too!

Dinosaur posture and body shape evolving up the evolutionary tree, with example taxa depicted. By Luis Rey.

News stories about this paper will be added below as they come out, featuring our favourites:

1) NERC’s Planet Earth, by Harriet Jarlett: “Dinosaur body shape changed the way birds stand“

2) Ed Yong on Phenomena: “Crouching  bird, hidden dinosaur“

3) Charles Choi on Live Science: “Crouching bird, hidden evolutionary purpose?“

4) Brian Handwerk on Nat Geo Daily News: “Birds’ “Crouching” Gait Born in Dinosaur Ancestors“

5) Jennifer Viegas on Discovery News: “Heavier dino arms led evolution to birds“

6) Puneet Kollipara on Science News: “Birds may have had to crouch before they could fly“

And some superb videos- we’re really happy with these:

1) Nature’s “Crouching Turkey, Hidden Dragon“

2) Reuters TV’s “3D study shows forelimb enlargement key to evolution of dinosaurs into birds“

Synopsis: Decent coverage, but negligible coverage in the general press; just science-specialist media, more or less. I think the story was judged to be too complex/esoteric for the general public. You’d think dinosaurs, evolution, computers plus physics would be an “easy sell” but it was not, and I don’t think we made any big errors “selling” it. Interesting– I continue to learn more about how unpredictable the media can be.

Regardless, the paper has had a great response from scientist colleagues/science afficionados, which was the target audience anyway. I’m very pleased with it, too– it’s one of my team’s best papers in my ~18 year career.

I love doing sciencey road trips with my team when I can. Last week, we got a treat: four of us got a behind-the-scenes tour of the fairly new Crocodiles of the World facility near Oxford; just over 90 minutes west of our lab, nestled in the pictureseque Cotswolds region. We were not disappointed, so you get to share in the joy! In photo-blog format. Pics can be clicked to emcrocken.

In the midst of an unpreposessing industrial estate lies: AWESOME!

If you want to bone up on your croc species, go here and here. I won’t go into details. This is an eye candy post!

Reasonably accurate description that caught my eye. My scientific interest in crocodiles starts here, and with their anatomy/relationship with dinosaurs, but I’ve loved crocs since I was an infant (one of my first words, as I may have written here before, was “dock-a-dile”, for my favourite stuffed animal at the time [R.I.P.]).

Siamese crocodiles. The large male is “Hugo.” They were apart when we entered, then got snuggly later, as I’ve often seen this species do. Heavily endangered (<300 in the wild?), so any breeding is a good thing!

The above photo brings me to one of my general points. Crocodiles of the World seems genuinely to be a centre that is breeding crocodiles for conservation purposes (and for education, entertainment and other zoo-like stuff). Essentially every crocodile enclosure had a mated pair, and several were breeding. Such as…

Yes, that is a Dwarf African crocodile, Osteolaemus, and indeed it is a female on her nest-mound. Which means…

Eggs of said Osteolaemus.

And babies of said Osteolaemus! As if the adults aren’t cute enough with their short snouts and doglike size/appearance! These guys have striking yellow colouration, too. I’d never seen it in person before.

That’s not all!

Male American Alligator “Albert” warming up. Smaller female partner “Daisy” lives in same enclosure. Plenty of babies from these guys, too! Daisy comes when called by name, and Albert is learning to do so.

~1 meter long juvenile Nile crocodiles, bred at the facility.

But then crocodile morphological diversity (colours, textures) and behaviour is just too cool not to focus on a bit, so here are some highlights from our visit!

Endearing shot of a crocodylian I seldom get to see anywhere: Paleosuchus trigonatus, the Schneider’s Dwarf Caiman. Spiny armoured hide and quite terrestrial; poorly known in many ways. Some more info is here (note its tortured taxonomy)

Black caiman, Melanosuchus niger, showing some interest in us.

Cuban crocodiles (Crocodylus rhombifer; pound for pound the most badass croc in my experience; badassitude that this photo captures nicely) cooling off by exposing the well-vascularized soft tissues of the mouth region.

But it’s not just crocs there, either, and some of the highlights were non-croc surprises and memorable encounters:

A surprisingly friendly and tame Water monitor (14 yrs old; does kids parties). Note person for scale. Was about 2 meters long, 20 kg or so.

Business end of nice Water monitor, with tongue engaged.

And we got a nice farewell from an African spur-thigh tortoise (Geochelone sulcata) with an oral fixation (action sequence thereof):

Chowmp!

If someone visits this facility and leaves without being converted to a croc-lover, they must be from a different planet than me. It is a celebration of crocodiles; the owner, Shaun Foggett, is the real deal. He sold his home and quit his job as a carpenter to care for crocodiles, and it seems to be a great success– about to get greater, as they have plans to move to a new, bigger, proper site! They are seeking funding, so if you can contribute go here.

Right then… UK residents and visitors: you need to go here! Badly! Get off the blog and go now. If it is a Saturday/Sunday (the cramped industrial estate location only allows the public then).

Otherwise just stew and imagine how much fun you could be having checking out crocodiles. I cruelly posted this on a Tuesday to ensure thorough marination of any croc-geeks.

Muhaha!  ;-)

(John: here’s a guest post from my former PhD student, soon to be 100% legit PhD, Dr., and all that jazz, Julia Molnar!)

This is my first guest post, but I have been avidly following what’s in John’s freezer (and the blog too) for quite a while. I joined the lab in 2009 and left a month ago on the bittersweet occasion of surviving my PhD viva (oral exam/defense), so I’d like to take a moment here to thank John and the Structure & Motion Lab for a great 4 years!

Moving on to freezer-related matters; specifically, a bunch of frozen crocodile spines. It was late 2011, and the reason for the spines in John’s freezer was that John, Stephanie Pierce, and I were trying to find out more about crocodile locomotion. This was anticipated to become my first major, first-author research publication (but see my Palaeontologia Electronica paper on a related subject), and I was about to find out that these things seldom go as planned; for example, the article would not be published for more than three years (the research took a long time!). Before telling the story of how it lurched and stumbled toward eventual publication, I’ll give you some background on the project.

Stomach-Churning Rating: 3/10; x-ray of dead bits and nothing much worse.

A stumbly sort-of-bounding crocodile. They can do better.

First of all, why crocodiles? For one thing, they’re large, semi-terrestrial animals, but they use more sprawling postures than typical mammals. Along with alligators and gharials, they are the only living representatives of Crocodylomorpha, a 200+ million year-old lineage that includes wolf-like terrestrial carnivores, fish-like giants with flippers and a tail fin, even armored armadillo-like burrowers. Finally, crocodiles are interesting in their own right because they use a wide variety of gaits, including bounding and galloping, which are otherwise known only in mammals.

Nile crocodile skeletal anatomy

OK, so why spines? Understanding how the vertebral column works is crucial to understanding locomotion and body support on land, and inter-vertebral joint stiffness (how much the joints of the backbone resist forces that would move them in certain directions) in particular has been linked to trunk movements in other animals. For this reason, vertebral morphology is often used to infer functional information about extinct animals, including dinosaurs. However, vertebral form-function relationships have seldom been experimentally tested, and tests on non-mammals are particularly scarce. So we thought the crocodile spines might be able to tell us more about the relationship between vertebral morphology, mechanics, and locomotion in a broader sample of vertebrate animals. If crocodile spine morphology could be used to predict joint stiffness, then morphological measurements of extinct crocodile relatives would have some more empirical heft to them. Several skeletal features seem to play roles such as levers to mechanically stiffen crocodile spines (click to emcroc’en):

Anatomy of a crocodile vertebra

We decided to use a very simple technique that could be replicated in any lab to measure passive stiffness in crocodile cadavers. We dissected out individual joints were and loaded with known weights. From the movement of the vertebrae and the distance from the joint, we calculated how much force takes to move the joint a certain number of degrees (i.e. stiffness).

Me with crocodile vertebra and G-clamp

X-ray of two crocodile vertebrae loaded with a metric weight to calculate their joint’s stiffness

Afterwards, we boiled the joints to remove the soft tissues – the smell was indescribable! We took 14 measurements from each vertebra. All of these measurements had been associated with stiffness or range of motion in other studies, so we thought they might be correlated with stiffness in crocodiles also.

Some of the vertebral measurements that were related to stiffness

Despite my efforts to keep it simple, the process of data collection and analysis was anything but. I recall and exchange with Stephanie Pierce that went something like this:

Stephanie: “How’s it going?”

Me: “Well, the data are messy, I’m not seeing the trends I expected, and everything’s taking twice as long as it was supposed to.”

Stephanie: “Yes, that sounds like science.”

That was the biggest lesson for me: going into the project, I had been unprepared for the amount of bumbling around and re-thinking of methods when the results were coming up implausible or surprising. In this case there were a couple of cool surprises: for one thing, crocodiles turn out to have a very different pattern of inter-vertebral joint stiffness than typical mammals: while mammals have stiff thoracic joints and mobile lumbar joints, crocodiles have stiffer lumbar joints. Many mammals use large lumbar movements during bounding and galloping, so crocodiles must use different axial mechanics than mammals, even during similar gaits. While that’s not shocking (they did evolve their galloping and bounding gaits, and associated anatomy, totally independently), it is neat that this result came out so clearly. Another unexpected result was that, although several of our vertebral measurements were correlated with stiffness, some of the best predictors of stiffness in mammals from previous studies were not correlated with stiffness in crocodiles. The study tells a cautionary tale about making assumptions about extinct animals using data from only a subset of their living relatives or intuitive ideas about form and function.

Finally, the experience of doing the experiments and writing the paper got me interested in other aspects of crocodilian functional anatomy. For instance, how does joint stiffness interact with other factors, such as muscle activity and properties of the ribs, skin, and armor in living crocodiles? Previous studies by Frey and Salisbury had commented on this, but the influence of those factors is less tractable to experiment on or model than just naked backbones with passively stiff joints. In the future, I’d like to study vertebral movements during locomotion in crocodiles – especially during bounding and galloping – to find out how these patterns of stiffness relate to movement. In the meantime, our study shows that, to a degree, crocodile backbone dimensions do give some clues about joint stiffness and locomotor function.

To find out more, read the paper! It was just featured in Inside JEB.

Julia Molnar, Stephanie Pierce, John Hutchinson (2014). An experimental and morphometric test of the relationship between vertebral morphology and joint stiffness in Nile crocodiles (Crocodylus niloticus). The Journal of Experimental Biology 217, 757-768 link here and journal’s “Inside JEB” story

I visited the British Museum a while ago with my daughter and was struck by some of the animal imagery in the loot on display– particularly, as an archosaurophile, the crocodiles (Crocodylia, crocodylians, etc.; no alligatoroids to show in this post). So I decided to go back and photograph some of them for a blog post about the more obscure and rare animals that sometimes appear in human art and design.

It’s easy to think of horses, lions, dogs, eagles and other familiar, domestic or prized beasts in human decorations. Yet what roles do less common animals play? This post is the first of two on the unsung beasties of human artwork, as represented in the British Museum.

Stomach-Churning Rating: 1/10. Tame art and a dried crocodile skin.

Wherever humans and crocodiles coexist, the primeval appearance and dangerous potential of crocodiles are sure to impress themselves upon our psyche. Hence they will manifest themselves in art. This should especially apply in the early days of a civilization, before we extirpate local crocodiles or exclude them to the hinterlands, or in cases in which crocodylians become revered and protected.

Much of Western culture lacks such an emphasis, because it developed in more temperate climes where crocodiles were long since absent. It’s fun to think about what our culture would be like if it had developed with crocodiles as a prominent aspect, as in Egypt, which is the natural place to begin our tour, featuring mummies of course!

All images can be clicked to emcroccen them.

Small Nile crocodile mummy from >30 B.C, El Hiba, Egypt

Second small Nile crocodile mummy from >30 B.C, El Hiba, Egypt

Those mummies remind me of a recent scientific study that used such mummies to reveal the history of the “cryptic” species Crocodylus suchus, a close relative of the Nile croc C. niloticus, and one that seems to be more threatened.

We proceed on our tour with a box showing an example of shabti, or doll-like funeral offerings of “enchanted” mummified figurines:

This shabti box was for a noble daughter, Neskshons, in Thebes, from around 650 B.C.

A crocodile deity receives the shabti from the departed soul, accompanied by serpent god as well as a more human, ankh-bearing divinity.

Next, some amazingly preserved papyrus scrolls:

This papyrus is from around 900 B.C., with short blurbs about the woman Tentosorkon, part of a new style of funeral provisions in the 22nd Dynasty of Egypt.

Crocodile featured in the story of Tentosorkon. What’s it doing? Why is a feathered snake-thing touching its butt? I wish I knew.

The “Litany of Ra”, from around 1000 B.C., which is a style like that of the previous 22nd Dynasty papyrus and would have decorated a tomb’s wall, dedicated to the lady Mutemwia. Ra, the sun god, is shown in his different manifestations, including a crocodile form, called Sobek-ra (AKA Sebek); a protector and comforter of the dead:

But crocodiles also feature prominently in other cultures around the world– I was hoping to find some in Thai, South American, or other cultures’ art (especially east/western Africa). However, the museum didn’t exhibit any I could find. I did find these, though, starting with this fantastic Roman armour with a great backstory (and hard to take photos of; argh!):

Roman soldiers in a Sobek cult, running around Egypt while wearing badass armour and getting into all kinds of Bronze Age trouble: I DEMAND TO SEE A SWORD-AND-SANDALS MOVIE FEATURING THIS!

I searched for this next one but did not see it:

A crocodile mask from Mabuiag island near Australia- for some cool details, see this page where the image comes from (I didn’t get to see the original).

There were more tenuous links to crocodiles– surely some dragon images throughout the world relate at least partly to crocodiles, such as this one which seems very crocodylian to me:

A water spirit figure called a belum, from Sarawak, Malaysia, 18/1900s. Belief among the Melanau people was that these dragons would wrap their tails around someone’s body to protect or drown them. Possibly inspired by saltwater or Phillipine crocs that they lived near.

And that’s it- all I managed to find, but not a bad haul from this huge museum.  I looked for the Aztec croc-god Cipactli to no avail. If you have £850 to spare you might like to walk away with this one from the museum. I gladly accept donations of such things to my, err, research.

That’s just one museum’s view of crocodylians’ role in our culture. What crocodile imagery from human art around the world do you fancy?

Even nine years later, I still keep thinking back to a day, early in my career as an academic faculty member based in England, that traumatized me. Today I’m going to share my story of that day. I feel ready to share it.

This day was part of a research trip that lasted a couple of weeks, and it was in Florida, not England, and little of that trip went well at first. It transpired almost exactly 9 years ago today; around 20 August 2005. I took two 2nd/3rd year undergraduate students and our lab technician with me to Florida, meeting up with Dr. Kent Vliet, an experienced crocodile specialist, to study the biomechanics of crocodile locomotion, a subject I’ve been slowwwwwwly working on since my PhD days (see recent related blog post here). We were funded by an internal grant from my university that was supposed to be seed money to get data to lay groundwork for a future large UK research grant.

Cuban crocodile adult relaxing in a nearby enclosure. Pound-for-pound, a scary croc, but these acted like puppies with their trainers.

I’m interested in why only some crocodylian species, of some sizes and age classes, will do certain kinds of gaits, especially mammal-like gaits such as bounding and galloping. This strongly hints at some kind of size-related biomechanical mechanism that dissuades or prevents larger crocs from getting all jiggy with it. And at large size, with few potential predators to worry about and a largely aquatic ambush predator’s ecology, why would they need to? Crocodiles should undergo major biomechanical changes in tune with their ecological shifts as they grow up. I want to know how the anatomy of crocodiles relates to these changes, and what mechanism underlies their reduction of athletic abilities like bounding. That’s the scientific motivation for working with animals that can detach limbs from your body. (The crocodiles we worked with initially on this trip were small (about 1 meter long) and not very dangerous, but they still would have done some damage if they’d chosen to bite us, and I’ve worked with a few really nasty crocs before.)

Me putting motion capture markers onto an uncooperative young Siamese crocodile.

We worked at Gatorland (near Orlando) with some wonderfully trained crocodiles that would even sit in your lap or under your chair, and listened to vocal commands. The cuteness didn’t wear off, but our patience soon did. First, the force platform we’d borrowed (from mentor Rodger Kram’s lab; a ~$10,000 piece of useful gear) and its digital data acquisition system wouldn’t work to let us collect our data. That was very frustrating and even a very helpful local LabView software representative couldn’t solve all our problems. But at least we were able to start trying to collect data after four painstaking days of debugging while curious crocodiles and busy animal handlers waited around for us to get our act together. The stress level of our group was already mounting, and we had limited time plus plenty of real-life bugs (the bitey, itchy kind; including fire ants) and relentless heat to motivate us to get the research done.

Adorable baby Cuban crocodile.

Then the wonderfully trained crocodiles, as crocodiles will sometimes do, decided that they did not feel like doing more than a slow belly crawl over our force platform, at best. This was not a big surprise and so we patiently tried coaxing them for a couple of sweltering August days. We were working in their caged paddock, which contained a sloping grassy area, a small wooden roofed area, and then at the bottom of the slope was the crocodiles’ pond, where they sat and chilled out when they weren’t being called upon to strut their stuff for science. We didn’t get anything very useful from them, and then the weather forecast started looking ugly.

Hybrid Siamese crocodile in its pond in our enclosure, waiting to be studied.

We’d been watching reports of a tropical storm developing off the southeastern coast of Florida, and crossing our fingers that it would miss us. But it didn’t.

When the storm hit, we were hoping to weather the edge of the storm while we packed up, because we decided we’d done our best but our time had run out and we should move to our next site, the Alligator Farm and Zoological Park in St Augustine, where I’d worked a lot before with other Crocodylia. But the storm caught us off guard, too soon, and too violently.

To give some context to the situation, for the previous several days the local croc handlers had told us stories of how lightning routinely struck this area during storms, and was particularly prone to hitting the fences on the park perimeter, which we were close to. There was a blasted old tree nearby that vultures hung out in, and they related how that blasting had been done by lightning. One trainer had been hit twice by (luckily glancing) blows from lightning hitting the fences and such.

Ominous onlooker.

The storm came with pounding rain and a lot of lightning, much of it clearly striking nearby- with almost no delay between flashes and thunder, and visible sky-to-ground bolts. We debated taking our forceplate out of the ground near the crocodile pond, because sensitive electrical equipment and rain don’t go well together, but this would take precious time. The forceplate was covered with a tarp to keep the rain off. I decided that, in the interest of safety, we needed to all seek shelter and let the forceplate be.

I’ll never forget the memory of leaving that crocodile enclosure and seeing a terrible sight. The crocodile pond had swiftly flooded and engulfed our forceplate. This flooding also released all the (small) crocodiles which were now happily wandering their enclosure where we’d been sitting and working before.

Another subject awaits science.

At that point I figured there was no going back. Lightning + deepening floodwater + electrical equipment + crocodiles = not good, so I wagered my team’s safety against our loaned equipment’s, favouring the former.

We sprinted for cars and keepers’ huts, and got split up in the rain and commotion. As the rain calmed down, I ventured out to find the rest of the team. It turned out that amidst the havoc, our intrepid lab technician had marshalled people to go fetch the forceplate out from the flooded paddock, storm notwithstanding. We quickly set to drying it out, and during some tense time over the next day we did several rounds of testing its electronics to see if it would still work. Nope, it was dead. And we still had over a week of time left to do research, but without our most useful device. (A forceplate tells you how hard animals are pushing against the ground, and with other data such as those from our motion analysis cameras, how their limbs and joints function to support them)

We went on to St Augustine and got some decent data using just our cameras, for a wide variety of crocodiles, so the trip wasn’t a total loss. I got trapped by remnants of the storm while in Washington, DC and had to sleep on chairs in Dulles Airport overnight, but I got home, totally wrecked and frazzled from the experience.

That poorly-timed storm was part of a series of powerful storms that would produce Hurricane Katrina several days later, after we’d all left Florida. So we had it relatively easy.

I’m still shaken by the experience- as a tall person who grew up in an area with a lot of dangerous storms, I was already uneasy about lightning, feeling like I had a target on my back. But running from the lightning in that storm, after all the warnings we’d had about its bad history in this area, and how shockingly close the lightning was, leaves me almost phobic about lightning strikes. I’m in awe of lightning and enjoy thunderstorms, which I’ve seen few of since I left Wisconsin in 1995, but I now hate getting caught out in them.

The ill-fated forceplate and experimental area.

Moreover, the damage to the forceplate- which we managed to pay to repair and return to my colleague, and the failure of the Gatorland experiments, truly mortified me. I felt horrible and still feel ashamed. I don’t think I could have handled the situation much differently. It was just a shitty situation. That, and I wanted to show our undergrads a good time with research, yet what they ended up seeing was a debacle. I still have the emails I sent back to my research dean to describe what happened in the event, and they bring back the pain and stress now that I re-read them. But then… there’s a special stupid part to this story.

I tried to lighten the mood one night shortly after the storm by taking the team out to dinner, having a few drinks and then getting up to sing karaoke in front of the restaurant. I sang one of my favourite J Geil’s Band tunes- I have a nostalgic weakness for them- the song “Centerfold“. I not only didn’t sing it well (my heart was not in it and my body was shattered), and tried lamely to get the crowd involved (I think no one clapped or sang along), but also in retrospect it was a bad choice of song to be singing with two female undergrads there– I hadn’t thought about the song’s meanings when I chose to sing it, I just enjoyed it as a fun, goofy song that brought me back to innocent days of my youth in the early 1980’s. But it is not an innocent song.

So ironically, today what I feel the most embarrassed about, thinking about that whole trip and the failed experiment, is that karaoke performance. It was incredibly graceless and ill-timed and I don’t think anyone enjoyed it. I needed to unwind; the stress was crushing me; but oh… it was so damn awkward. I think I wanted to show to the team “I’m OK, I can still sing joyfully and have a good time even though we had a disastrous experiment and maybe nearly got electrified or bitten by submerged crocodiles or what-not, so you can relax too; we can move on and enjoy the rest of the trip” but in reality I proved to myself, at least, that I was not OK. And I’m still not OK about that experience. It still makes me cringe. Haunted, it took me many years to feel comfortable singing karaoke again.

It should have been a fun trip. I love working with crocodiles, but Florida is a treacherous place for field work (and many other things). I can’t say I grew stronger from this experience. There is no silver lining. It sucked, and I continually revisit it in my memory trying to find a lesson beyond “choose better times and better songs to sing karaoke with” or “stay away from floods, electricity and deadly beasts.”

So that wins, out of several good options, as the worst day(s) of my career that I can recall. I’ve had worse days in my life, but for uncomfortable science escapades this edges out some other contenders. Whenever I leave the lab to do research, I think of this experience and hope that I don’t see anything worse. It could have been much worse field work.

(Epilogue: the grants we’ve tried to fund for this crocodile gait project all got shot down, so it has lingered and we’ve done research on it gradually since, when we find time and students… And one of the students on this trip went on to do well in research and is finishing a PhD in the Structure & Motion Lab now, so we didn’t entirely scare them off science!)

Seeking adaptations for running and swimming in the vertebral columns of ancient crocs

A guest post by Dr. Julia Molnar, Howard University, USA (this comes from Julia’s PhD research at RVC with John & colleagues)

Recently, John and I with colleagues Stephanie Pierce, Bhart-Anjan Bhullar, and Alan Turner described morphological and functional changes in the vertebral column with increasing aquatic adaptation in crocodylomorphs (Royal Society Open Science, doi 10.1098/rsos.150439). Our results shed light upon key aspects of the evolutionary history of these under-appreciated archosaurs.

Stomach-Churning Rating: 5/10; a juicy croc torso in one small photo but that’s all.

Phylogenetic relationships of the three crocodylomorph groups in the study and our functional hypotheses about their vertebrae. * Image credits: Hesperosuchus by Smokeybjb, Suchodus by Dmitry Bogdanov (vectorized by T. Michael Keesey) http://creativecommons.org/licenses/by-sa/3.0

As fascinating as modern crocodiles might be, in many ways they are overshadowed by their extinct, Mesozoic cousins and ancestors. The Triassic, Jurassic, and early Cretaceous periods saw the small, fast, hyper-carnivorous “sphenosuchians,” the giant, flippered marine thalattosuchians, and various oddballs like the duck-billed Anatosuchus and the aptly named Armadillosuchus. As palaeontologists/biomechanists, we looked at this wide variety of ecological specializations in those species, the Crocodylomorpha, and wanted to know, how did they do it?

Of course, we weren’t the first scientists to wonder about the locomotion of crocodylomorphs, but we did have some new tools in our toolbox; specifically, a couple of micro-CT scanners and some sophisticated imaging software. We took CT and micro-CT scans of five fossil crocodylomorphs: two presumably terrestrial early crocodylomorphs (Terrestrisuchus and Protosuchus), three aquatic thalattosuchians (Pelagosaurus, Steneosaurus, and Metriorhynchus) and a semi-aquatic modern crocodile (Crocodylus niloticus). Since we’re still stuck on vertebrae (see, e.g., here; and also here), we digitally separated out the vertebrae to make 3D models of individual joints and took measurements from each vertebra. Finally, we manipulated the virtual joint models to find out how far they could move before the bones bumped into each other or the joints came apart (osteological range of motion, or RoM).

Our methods: get fossil (NHMUK), scan fossil, make virtual fossil and play with it.

Above: Video of a single virtual inter-vertebral joint from the trunk of Pelagosaurus typus (NHMUK) showing maximum osteological range of motion in the lateral direction (video). Note the very un-modern-croc-like flat surfaces of the vertebral bodies! (modern crocs have a ball-and-socket spinal joint with the socket on the front end)

While this was a lot of fun, what we really wanted to find out was whether, as crocodylomorphs became specialized for different types of locomotion, the shapes of their vertebrae changed similarly to those of mammalian lineages. For example, many terrestrial mammals have a lumbar region that is very flexible dorsoventrally to allow up-and-down movements during bounding and galloping. Did fast-running crocodylomorphs have similar dorsoventral flexibility? And did fast-swimming aquatic crocodylomorphs evolve a stiffer vertebral column like that of whales and dolphins?

Above: Video of how we modelled and took measurements from the early crocodylomorph Terrestrisuchus gracilis (NHMUK).

Our first results were puzzling. The Nile croc had greater RoM in side-to-side motions, which makes sense because crocodiles mostly use more sprawling postures and are semi-aquatic, using quite a bit of side-to-side motions in life. The part that didn’t make sense was that we found pretty much the same thing in all of the fossil crocodylomorphs, including the presumably very terrestrial Terrestrisuchus and Protosuchus. With their long limbs and hinge-like joints, these two are unlikely to have been sprawlers or swimmers!

So we started looking for other parts of the croc that might affect RoM. The obvious candidate was osteoderms, the bony scales that cover the back. We went back to John’s Freezer and got out a nice frozen crocodile to measure the stiffness of its trunk and found that, sure enough, it was a lot stiffer and less mobile without the osteoderms. If the fairly flexible arrangement of osteoderms in crocodiles had this effect on stiffness, it seemed likely that (as previous authors have suggested; Eberhard Frey and Steve Salisbury being foremost amongst them) the rigid, interlocking osteoderms running from head to tail in early crocodylomorphs would really have put the brakes on their ability to move their trunk in certain ways.

Testing the stiffness of (Nile) crocodile trunks to learn the effects of osteoderms, skin, muscles, and ribs. We hung metric weights from the middle of the trunk and measured how much it flexed (Ɵ), then removed bits and repeated. Click to em-croccen.

Another cool thing we found was new evidence of convergent evolution to aquatic lifestyles in the spines of thalattosuchians. The more basal thalattosuchians, thought to have been near-shore predators, had stiffness and RoM patterns similar to Crocodylus. But Metriorhynchus, which probably was very good at chasing down fast fish in the open ocean, seems to have had greater stiffness. (The stiffness estimates come from morphometrics and are based on modern crocodiles; see here again, or just read the paper already!) A stiff vertebral column can be useful for a swimmer because it increases the body’s natural frequency of oscillation, and faster oscillation means faster swimming (think tuna, not eel). The same thing seems to have happened in other secondarily aquatic vertebrate lineages such as whales, ichthyosaurs, and mosasaurs.

So, our results were a mixed bag of adaptations particular to crocs and ones that seem like general vertebrate swimming specializations. Crocodylomorphs are important because they are the only group of large vertebrates other than mammals that has secondarily aquatic members and has living members with a reasonably similar body plan, allowing us to test hypotheses in ways that would arguably be impossible for, say, non-avian dinosaurs and birds. The take-home message: crocodylomorphs A) are awesome, and B) can teach us a lot about how vertebrates adapt to different modes of life.

Another take on this story is on our lab website here.

Sorry about the title. It’s the best I could do. In case you missed it on our Anatomy to You blog, we unleashed a hefty database of CT (and some MRI) scans of our frozen crocodile cadavers last week, for free public usage. In total, it’s about 34 individuals from 5 species, in 53 databases constituting around 26,000 individual DICOM file format slices of data. This page has a table of what the data/specimens are. I am writing this post to share some more images and ensure that word gets out. We’re thrilled to be able to finally release this first dataset. We have plans to let loose a LOT more such data in the future, for various organisms that we study.

Stomach-Churning Rating: 2/10- be glad that these data don’t come with an olfactory component, especially the five rotten, maggot-ridden Morelet’s croc specimens, which are among the stinkiest things I’ve dealt with.

Crocodiles are no strangers to this blog, of course, as these past links testify. Indeed, most of the crocodile images I’ve blogged with come from specimens that are in this scan dataset. We even released a “celebrity crocodile, “WCROC” or FNC7 in our dataset, which is the 3.7m long Nile croc from “Inside Nature’s Giants”. It broke our CT scanner back in ~2009 but we got the data, except for the torso, and we also got some MRI scans from it, so we’re chuffed.

Above: The only spectacled caiman (Caiman crocodilus); and indeed the only alligatorid; in our dataset. To watch for: stomach contents/gastroliths, and all the damn osteoderms that I did/didn’t segment in this quickly processed file. This specimen had its limbs dissected for one of our studies, so only the right limbs are visible.

There are some more specimens to come- e.g. five baby Nile crocs‘ datasets (“GNC1-5”) are hiding somewhere in our drives and we just need to dig them up. You might also know that we published some scan data for crocodile vertebral columns (including fossils) in our recent paper with Julia Molnar et al. (and related biomechanical data discussed here), and we published all of our anatomical measurements for a huge set of crocodylian species in our papers by Vivian Allen et al. And then I had an enjoyable collaboration with Colleen Farmer and Emma Schachner on the lung anatomy of various crocodylian species, using these same specimens and related scan datasets.

Above: rotating Crocodylus moreletii (specimen FMC5 from our database) in a happy colour.

Sharing these kind of huge datasets isn’t so easy. Not only do few websites host them cheaply, and with reasonable file size limits, and limited headaches for what info you have to provide, and with some confidence that the websites/databases will still exist in 5-20 years, but also we were hesitant to release the dataset until we felt that it was nicely curated. Researchers can now visit my lab and study the skeletons (or in some cases, the still-frozen specimens) matched up with the scan data, and known body masses or other metadata. We’re not a museum with dedicated curatorial staff, so that was not trivial to reliably organize, and I still worry that somewhere in the dataset we mis-identified a specimen or something. But we’ve done our best, and I’m happy with that for now.

Above: rotating Osteolaemus tetraspis (specimen FDC2 from our database), which was obviously dissected a bit postmortem before we could scan it, but still shows some cool features like the extensive bony armour and the cute little doglike (to me, anyway) skull. I worked with these animals (live) a bit >10 years ago and came to love them. Compared to some other crocodiles we worked with, they had a pleasant demeanour. Like this guy:

Osteolaemus (resting) set up with motion capture markers for a yet-to-be-published gait study that we did in 2005 (ugh!). It wasn’t harmed by this.

Anyway, as a person who likes to maintain quality in the science we do, I also was hesitant to “just” release the DICOM file data rather than beautiful segmented 3D skeletal (or other tissue) geometry that is ready for 3D printing or animation or other uses, or interactive online tools like Sketchfab. Other labs (e.g. Witmerlab) do these kind of things better than we do and they inspire us to raise our game in the future, but I am sure that we will be forgiven for releasing big datasets without gorgeous visuals and more practical, processed files — this time.  We agree with many other scientists that sharing data is part of modern, responsible science– and it can be fun, too! Oddly enough, in this case we hadn’t used the CT/MRI data much for our own studies; most of the scans were never fully digitized. We just scan everything we get and figured it was time to share these scans.

Enjoy. If you do something cool with the data that we’ve made accessible, please let us know so we can spread the joy!

And if you’re a researcher headed to ICVM next week, I hope to see you there!

GIF of the human biceps (above) and its antagonist triceps (below) in action- By “Niwadare” – own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=38718790

Last year on Darwin Day I debuted “Better Know A Muscle” (BKAM), which was intended to be a series of posts focusing on one cool muscle at a time, and its anatomical, functional and evolutionary diversity and history. A year later, it’s another post on another muscle! Several dozen more muscles to go, so I’ve got my work cut out for me… But today: get ready to FLEX your myology knowledge! Our subject is Musculus biceps brachii; the “biceps” (“two-headed muscle of the arm”). Beloved of Arnie and anatomists alike, the biceps brachii is. Let’s get pumped up!

Stomach-Churning Rating: 7/10. Lots of meaty elbow flexion!

While the previous BKAM’s topic was a hindlimb muscle with a somewhat complex history (and some uncertainties), the biceps brachii is a forelimb muscle with a simpler, clearer history. Fish lack a biceps, just having simple fin ab/adductor muscles with little differentiation. Between fish and tetrapods (limb-bearing vertebrates), there was an explosion in the number of muscles; part of transforming fins into limbs; and the biceps is thenceforth evident in all known tetrapods in a readily identifiable anatomical form. In salamanders and their amphibian kin, there is a muscle usually called “humeroantebrachialis” that seems to be an undivided mass corresponding to the biceps brachii plus the brachialis (shorter humerus-to-elbow) muscle:

Most of the humerobrachialis muscle (purplish colour), in dorsal (top) view of the right forelimb of the fire salamander Salamandra salamandra (draft from unpublished work by my team).

In all other tetrapods; the amniote group (reptiles, mammals, etc.); there is a separate biceps and brachialis, so these muscles split up from the ancestrally single “humeroantebrachialis” muscle sometime after the amphibian lineage diverged from the amniotes. And not much changed after then– the biceps is a relatively conservative muscle, in an evolutionary (not political!) sense. In amniote tetrapods that have a biceps, it develops as part of the ventral mass of the embryonic forelimb along with other muscles such as the shorter, humerus-originating brachialis, from which it diverges late in development (reinforcing that these two muscles are more recent evolutionary divergences, too).

Biceps brachialis or humerobrachialis, the “biceps group” tends to originate just in front of the shoulder (from the scapula/coracoid/pectoral girdle), running in front of (parallel to) the humerus. It usually forms of two closely linked heads (hence the “two heads” name), most obviously in mammals; one head is longer and comes from higher/deeper on the pectoral girdle, whereas the other is closer to the shoulder joint and thus is shorter. The two heads fuse as they cross the shoulder joint and we can then refer to them collectively as “the biceps”. It can be harder to see the longer vs. shorter heads of the biceps in non-mammals such as crocodiles, or they may be more or less fused/undifferentiated, but that’s just details of relatively minor evolutionary variation.

The biceps muscle then crosses in front of the elbow to insert mainly onto the radius (bone that connects your elbow to your wrist/thumb region) and somewhat to the ulna (“funny bone”) via various extra tendons, fascia and/or aponeuroses. The origin from the shoulder region tends to have a strong mark or bony process that identifies it, such as the coracoid process in most mammals (I know this well as I had my coracoid process surgically moved!). The insertion onto the radius tends to have a marked muscle scar (the radial tuberosity or a similar name), shared with the brachialis to some degree. A nice thing about the biceps is that, because it may leave clear tendinous marks on the skeleton, we sometimes can reconstruct how its attachments and path evolved (and any obvious specializations; even perhaps changes of functions if/when they happened).

Here are some biceps examples from the world of crocodiles:

Crocodile’s right forelimb showing the huge pectoralis, and the biceps underlying it; on the bottom right (“BB”- click to embiceps it).

Crocodile left forelimb with biceps visible (“BB”) on the left.

Crocodile biceps muscle cut off, showing the proximal (to right) and distal (to left) tendons (and long parallel muscle fibres) for a typical amniote vertebrate.

What does the biceps muscle do? It flexes (draws forward) the shoulder joint/humerus, and does the same for the elbow/forearm while supinating it (i.e. rotating the radius around the ulna so that the palm faces upwards, in animals like us who can rotate those two bones around each other). In humans, which have had their biceps muscles studied by far the most extensively, we know for example that the biceps is most effective at flexing the elbow (e.g. lifting a dumbbell weight) when the elbow is moderately straight. These same general functions (shoulder and elbow flexion; with some supination) prevail across the biceps muscle of [almost; I am sure there are exceptions] all tetrapods, because the attachments and path of the biceps brachii are so conservative.

And this flexor function of the biceps brachii stands in contrast to our first BKAM muscle, the caudofemoralis (longus): that muscle acts mainly during weight support (stance phase) as an antigravity/extensor muscle, whereas the flexor action of biceps makes it more useful as a limb protractor or “swing phase” muscle used to collapse the limb and draw it forwards during weight support. However, mammals add some complexity to that non-supportive function of the biceps…

Hey mammals! Show us your biceps!

Jaguar forelimb with biceps peeking out from the other superficial muscles, and its cousin brachialis nicely visible, running along the front of the forearm for a bit.

Elephant’s left forelimb with the biceps labelled.

Longitudinal slice thru the biceps of an elephant, showing the internal tendon that helps identify where the two bellies of the biceps fuse.

In certain mammals; the phylogenetic distribution of which is still not clear; the biceps brachii forms a key part of a passive “stay apparatus” that helps keep the forelimb upright against gravity while standing (even sleeping). The classic example is in horses but plenty of other quadrupedal mammals, especially ungulate herbivores, show evidence of similar traits:

Giraffe biceps cut away proximally to show the “stay apparatus” around the shoulder joint (upper right).

Zooming in on the “stay apparatus”; now in proximal view, with the biceps tendon on the left and the humeral head (showing some arthritic damage) on the right, with the groove for the biceps in between.

Hippo’s humerus (upper left) and biceps muscle cut away proximally, displaying the same sort of “stay apparatus” as in the giraffe. Again, note the stout proximal and distal tendons of the biceps. The proximal tendon fits into the groove of the humerus on the far left side of the image; becoming constrained into a narrow circular “tunnel” there. It’s neat to dissect that region because of its fascinating relationships between bone and soft tissues.

The biceps brachii, in those mammals with a stay apparatus, seems to me to have a larger tendon overall, especially around the shoulder, and that helps brace the shoulder joint from extending (retracting) too far backward, whilst also transmitting passive tension down the arm to the forearm, and bracing the elbow (as well as distal joints via other muscles and ligaments). It’s a neat adaptation whose evolution still needs to be further inspected.

Otherwise, I shouldn’t say this but the biceps is sort of boring, anatomically. Whether you’re a lizard, croc, bird or mammal, a biceps is a biceps is a biceps; more or less-ceps. But the biceps still has a clear evolutionary history and Darwin would gladly flex his biceps to raise a pint in toast to it.

So now we know a muscle better. That’s two muscles now. And that is good; be you predator or prey. Let’s shake on it!

PREDATOR HANDSHAKE!!!!!

As 2017 approaches its end, there have been a few papers I’ve been involved in that I thought I’d point out here while I have time. Our DAWNDINOS project has been taking up much of that time and you’ll see much more of that project’s work in 2018, but we just published our first paper from it! And since the other two recent papers involve a similar theme of muscles, appendages and computer models of biomechanics, they’ll feature here too.

Stomach-Churning Rating: 0/10; computer models and other abstractions.

Mussaurus patagonicus was an early sauropodomorph dinosaur from Argentina, and is now widely accepted to be a very close relative of the true (giant, quadrupedal) sauropods. Here is John Conway’s great reconstruction of it:

We have been working with Alejandro Otero and Diego Pol on Mussaurus for many years now, starting with Royal Society International Exchange funds and now supported by my ERC grant “DAWNDINOS”. It features in our grant because it is a decent example of a large sauropodomorph that was probably still bipedal and lived near the Triassic-Jurassic transition (~215mya).

In our new study, we applied one of my team’s typical methods, 3D musculoskeletal modelling, to an adult Mussaurus’s forelimbs. This is a change of topic from the hindlimbs that I’ve myopically focused on before with Tyrannosaurus and Velociraptor [in an obscure paper that I should never have published in a book! pdf link], among other critters my team has tackled (mouse, elephant [still to be finished…], ostrich, horse, Ichthyostega… dozens more to come!). But we also modelled the forelimbs of Crocodylus johnstoni (Australian “freshie”) for a key comparison with a living animal whose anatomy we actually knew, rather than reconstructed.

Mussaurus above; Crocodylus below; forelimb models in various views; muscles are red lines.

The methods for this biomechanical modelling are now standard (I learned them from their creator Prof. Scott Delp during my 2001-2003 postdoc at Stanford): scan bones, connect them with joints, add muscle paths around them, and then use the models to estimate joint ranges of motion and muscle moment arms (leverage) around joints. I have some mixed feelings about developing this approach in our 2005 paper that is now widely used by the few teams that study appendicular function in extinct animals. As a recent review paper noted and I’ve always cautioned, it has a lot of assumptions and problems and one must exercise extreme caution in its design and interpretation. Our new Mussaurus paper continues those ruminations, but I think we made some progress, too.

On to the nuts and bolts of the science (it’s a 60 page paper so this summary will omit a lot!): first, we wanted to know how the forelimb joint ranges of motion in Mussaurus compared with those in Crocodylus and whether our model of Mussaurus might be able to be placed in a quadrupedal pose, with the palms at least somewhat flat (“pronated”) on the ground. Even considering missing joint cartilage, this didn’t seem very plausible in Mussaurus unless one allowed the whole forearm to rotate around its long axis from the elbow joint, which is very speculative—but not impossible in Crocodylus, either. Furthermore, the model didn’t seem to have forelimbs fully adapted yet for a more graviportal, columnar posture. Here’s what the model’s mobility was like:

So Mussaurus, like other early sauropodomorphs such as Plateosaurus, probably wasn’t quadrupedal, and thus quadrupedalism must have evolved very close to in the Sauropoda common ancestor.

Second, we compared the muscle moment arms (individual 3D “muscle actions” for short) in different poses for all of the main forelimb muscles that extend (in various ways and extents) from the pectoral girdle to the thumb, for both animals, to see how muscle actions might differ in Crocodylus (which would be closer to the ancestral state) and Mussaurus. Did muscles transform their actions in relation to bipedalism (or reversal to quadrupedalism) in the latter? Well, it’s complicated but there are a lot of similarities and differences in how the muscles might have functioned; probably reflecting evolutionary ancestry and specialization. What I found most surprising about our results was that the forelimbs didn’t have muscles well-positioned to pronate the forearm/hand, and thus musculoskeletal modelling of those muscles reinforced the conclusions from the joints that quadrupedal locomotion was unlikely. I think that result is fairly robust to the uncertainties, but we’ll see in future work.

You like moment arms? We got moment arms! 15 figures of them, like this! And tables and explanatory text and comparisons with human data and, well, lots!

If you’re really a myology geek, you might find our other conclusions about individual muscle actions to be interesting—e.g. the scapulohumeralis seems to have been a shoulder pronator in Crocodylus vs. supinator in Mussaurus, owing to differences in humeral shape (specialization present in Mussaurus; which maybe originated in early dinosaurs?). Contrastingly, the deltoid muscles acted in the same basic way in both species; presumed to reflect evolutionary conservation. And muuuuuuch more!

Do you want to know more? You can play with our models (it takes some work in OpenSim free software but it’s do-able) by downloading them (Crocodylus; Mussaurus; also available: Tyrannosaurus, Velociraptor!). And there will be MUCH more about Mussaurus coming soon. What is awesome about this dinosaur is that we have essentially complete skeletons from tiny hatchlings (the “mouse lizard” etymology) to ~1 year old juveniles to >1000kg adults. So we can do more than arm-wave about forelimbs!

But that’s not all. Last week we published our third paper on mouse hindlimb biomechanics, using musculoskeletal modelling as well. This one was a collaboration that arose from past PhD student James Charles’s thesis: his model has been in much demand from mouse researchers, and in this case we were invited by University of Virginia biomechanical engineers to join them in using this model to test how muscle fibres (the truly muscle-y, contractile parts of “muscle-tendon units”) change length in walking mice vs. humans. It was a pleasure to re-unite in coauthorship with Prof. Silvia Blemker, who was a coauthor on that 2005 T. rex hindlimb modelling paper which set me on my current dark path.

Mouse and human legs in right side view, going through walking cycles in simulations. Too small? Click to embiggen.

We found that, because mice move their hindlimb joints through smaller arcs than humans do during walking and because human muscles have large moment arms, the hindlimb muscles of humans change length more—mouse muscles change length only about 48% of the amount that typical leg muscles do in humans! This is cool not only from an evolutionary (mouse muscles are probably closer to the ancestral mammalian state) and scaling (smaller animals may use less muscle excursions, to a point, in comparable gaits?) perspective, but it also has clinical relevance.

Simulated stride for mouse and human; with muscles either almost inactive (Act=0.05) or fully active (Act=1). Red curve goes through much bigger excursions (along y-axis) than blue curve), so humans should use bigger % of their muscle fibre lengths in walking. Too small? Click to embiggen.

My coauthors study muscular dystrophy and similar diseases that can involve muscle stiffness and similar biomechanical or neural control problems. Mice are often used as “models” (both in the sense of analogues/study systems for animal trials in developing treatments, and in the sense of computational abstractions) for human diseases. But because mouse muscles don’t work the same as human muscles, especially in regards to length changes in walking, there are concerns that overreliance on mice as human models might cause erroneous conclusions about what treatments work best to reduce muscle stiffness (or response to muscle stretching that causes progressive damage), for example. Thus either mouse model studies need some rethinking sometimes, or other models such as canines might be more effective. Regardless, it was exciting to be involved in a study that seems to deliver the goods on translating basic science to clinical relevance.

Muscle-by-muscle data; most mouse muscles go through smaller excursions; a few go through greater; some are the same as humans’.

Finally, a third recent paper of ours was led by Julia Molnar and Stephanie Pierce (of prior RVC “Team Tetrapod” affiliation), with myself and Rui Diogo. This study tied together a bunch of disparate research strands of our different teams, including musculature and its homologies, the early tetrapod fossil record, muscle reconstruction in fossils, and biomechanics. And again the focus was on forelimbs, or front-appendages anyway; but turning back the clock to the very early history of fishes, especially lobe-finned forms, and trying to piece together how the few pectoral fin muscles of those fish evolved into the many forelimb muscles of true tetrapods from >400mya to much more recent times.

Humerus in ventral view, showing muscle attachments. Extent (green) is unknown in the fossil but the muscle position is clear (arrow).

We considered the homologies for those muscles in extant forms, hypothesized by Diogo, Molnar et al., in light of the fossil record that reveals where those muscles attach(ed), using that reciprocal illumination to reconstruct how forelimb musculature evolved. This parallels almost-as-ancient (well, year 2000) work that I’d done in my PhD on reconstructing hindlimb muscle evolution in early reptiles/archosaurs/dinosaurs/birds. Along the way, we could reconstruct estimates of pectoral muscles in various representative extinct tetrapod(omorph)s.

Disparity of skeletal pectoral appendages to work with from lobe-fins to tetrapods.

Again, it’s a lengthy, detailed study (31 pages) but designed as a review and meta-analysis that introduces readers to the data and ideas and then builds on them in new ways. I feel that this was a synthesis that was badly needed to tie together disparate observations and speculations on what the many, many obvious bumps, squiggles, crests and tuberosities on fossil tetrapods/cousins “mean” in terms of soft tissues. The figures here tell the basic story; Julia, as usual, rocked it with some lovely scientific illustration! Short message: the large number of pectoral limb muscles in living tetrapods probably didn’t evolve until limbs with digits evolved, but that number might go back to the common ancestor of all tetrapods, rather than more recently. BUT there are strong hints that earlier tetrapodomorph “fishapods” had some of those novel muscles already, so it was a more stepwise/gradual pattern of evolution than a simple punctuated event or two.

Colour maps of reconstructed right fin/limb muscles in tetrapodomorph sarcopterygian (~”fishapod”) and tetrapod most recent common ancestors. Some are less ambiguous than others.

That study opens the way to do proper biomechanical studies (like the Mussaurus study) of muscle actions, functions… even locomotor dynamics (like the mouse study)– and ooh, I’ve now tied all three studies together, tidily wrapped up with a scientific bow! There you have it. I’m looking forward to sharing more new science in 2018. We have some big, big plans!

I had a spare hour in Cambridge this weekend so I dared the crowds in the revamped UMZC’s upper floor. In my prior visit and post I’d experienced and described the lower floor, which is almost exclusively mammals. This “new” floor has everything else that is zoological (animal/Metazoa) and again is organized in an evolutionary context. And here is my photo tour as promised!

Inviting, soft lighting perfuses the exhibits from the entryway onwards.

All images can be clicked to mu-zoom in on them.

Stomach-Churning Rating: 5/10 for spirit animals, by which I mean dissected/ghostly pale whole specimens of animals in preservative fluids.

The exhibits are on a square balcony overlooking the lower floor, so you can get some nice views. It does make the balcony crowded when the museum is busy, so take that in mind if visiting. Strollers on this upper floor could be really difficult. But the ceiling is very tall so it is not cramped in a 3D sense. The lower floor is more spacious.

Like phylogenies? You got em! Tucked away at the beginning of each major group; not occupying huge valuable space or glaringly obvious like AMNH in NYC but still noticeable and useful. To me, it strikes a good balance; gives the necessary evolutionary context for the displayed specimens/taxa.

Introductory panels explain how names are given to specimens, how specimens are preserved and more.

The exhibits give due focus to research that the UMZC is doing or has been famous for. Hey I recognize that 3D tetrapod image in the lower left!

There is ample coverage of diversity throughout Metazoa but my camera tended to be drawn to the Vertebrata. Except in some instances like these.

Some larger chelicerates.

Some smaller, shadowy sea scorpion (eurypterid) fossils.

Watch here for more about ophiuroids (brittlestars) in not too long!

A BIG fish brain! Interesting!
Before I go through specimens in evolutionary “sequence”, I will feature another thing i really liked: lots of dissected spirit-specimens that show off cool anatomy/evolution/adaptation (and technical skills in anatomical preparation). Mostly heads; mostly fish.

Salps and other tunicates! Our closest non-vertebrate relatives- and some insight into how our head and gut came to be.

Salp-reflection.

Lamprey head: not hard to spot the commonalities with the salps; but now into Vertebrata.

Hagfish head: as a fellow cyclostome/agnathan, much like a lamprey but never forget the slime glands!

Shark head. Big fat jaws; all the better to bite prey with!

Lungfish (Protopterus) head showing the big crushing tooth plates (above).

Sturgeon vertebrae: tweak some agnathan/shark bits and here you are.

Carp head, with explainer on the Weberian apparatus linking the ear to the swim bladder.

Worm (annelid) anatomy model, displaying some differences from/similarities to Vertebrata. (e.g. ventral vs. dorsal nerve cord; segmentation)

Dissected flipper from a small whale/other cetacean. Still five fingers, but other specializations make it work underwater.

Wonderful diversity of tooth and jaw forms in sharks, rays and relatives. I like this display a lot.

More of the above, but disparate fossil forms!

On with the evolutionary context! Woven throughout the displays of modern animals are numerous fossils, like these lovely placoderms (lineage interposed between agnathans, sharks and other jawed fish).

Goblin shark head.

I seem to always forget what ray-finned fish this is (I want to say wolffish? Quick Googling suggests maybe I am right), but see it often and like its impressive bitey-ness.

Bichir and snakefish; early ray-finned fish radiations.

Armoured and similar fish today.

Armoured fish of the past; some convergent evolution within ray-fins.

Convergence- and homology- of amphibious nature in fish is another evolutionary pattern exemplified here.

Gorgeous fossils of ray-finned fish lineages that arose after the Permian extinctions, then went extinct later in the Triassic.

Note the loooooong snout on this cornetfish but the actual jaws are just at the tip.

Flying fish– those ray-fins are versatile.

Diversity of unusual ray-finned fish, including deep-water and bottom-dwelling forms.

Can you find the low-slung jaws of a dory?

Recent and fossil perch lineage fish.

It’s hard to get far into talking about evolution without bringing up the adaptive radiation of east African cichlid fish, and UMZC researchers are keen on this topic too.

Lobe-fins! Everybody dance!

Rhizodonts & kin: reasons to get out of Devonian-Carboniferous waters.

A Cretaceous fossil coelacanth (skull); not extremely different from living ones’.

Let’s admire some fossil and modern lungfish skulls, shall we? Big platey things  (here, mainly looking at the palate) with lots of fusions of tiny bones on the skull roof.

Eusthenopteron fossils aren’t that uncommon but they are still great to see; and very important, because…

OK let’s stop messing around. The UMZC has one of the best displays of fossil stem-tetrapods in the world! And it should.

Another look at the pretty Acanthostega models.

Acanthostega vs. primate forelimb: so like us.

Ichthyostega parts keep Acanthostega company.

A closer look at the “Mr. Magic” Ichthyostega specimen, which takes some unpacking but is incredibly informative and was a mainstay of our 2012 model. Back of skull, left forelimb, and thorax (from left to right here).

Eucritta, another stem-tetrapod.

Closer look at Eucritta‘s skull.

Weird stem-tetrapod Crassigyrinus, which we’re still trying to figure out. It’s a fabulous specimen in terms of completeness, but messy “roadkill” with too many damn bones.

The large skull of Crassigyrinus, in right side view.

Early temnospondyl (true amphibian-line) skulls and neck.

Nectrideans or the boomerangs of the Palaeozoic.

Cool fossil frogs.

Giant Japanese salamander!

Fire salamanders: not as colourful as the real thing, but here revealing their reproductive cycle in beautiful detail.

Closeup of oviduct in above.

Sexual dimorphism in Leptodactylus frogs: the males have bulging upper arms to (I am assuming) help them hold onto females during amplexus (grasping in mating competitions).

Did I forget that Leptodactylus has big flanges on the humerus in males, to support those muscles? Seems so.

An early stem-amniote, Limnoscelis (close to mammals/reptiles divergence); cast.

Grand sea turtle skeleton.

One of my faves on display: a real pareiasaurian reptile skeleton, and you can get a good 3D look around it.

Details on above pareiasaurian.

Mammals are downstairs, but we’re reminded that they fit into tetrapod/amniote evolution nonetheless.

Let there be reptiles! And it was good.

Herps so good.  (slow worm, Gila monster, glass lizard)

A curator is Dr Jason Head so you bet Titanoboa is featured!

Crocodylia: impressive specimens chosen here.

It ain’t a museum without a statuesque ratite skeleton. (There are ~no non-avian dinosaurs here– for those, go to the Sedgwick Museum across the street, which has no shortage!)

Avian diversity takes off.

Glad to see a tinamou make an appearance. They get neglected too often in museums- uncommon and often seemingly unimpressive, but I’m a fan.

I still do not understand hoatzins; the “cuckoo” gone cuckoo.

Dodo parts (and Great Auk) near the entrance.

Wow. What an oilbird taxidermy display! :-O

There we have it. Phew! That’s a lot! And I left out a lot of inverts. This upper floor is stuffed with specimens; easier there because the specimens are smaller on average than on the lower floor. Little text-heavy signage is around. I give a thumbs-up to that– let people revel in the natural glory of what their eyes show them, and give them nuggets of info to leave them wanting more so they go find out.

Now it’s in your hands– go find out yourself how lovely this museum is! I’ve just given a taste.

To me, there is no question that the Galerie de Paléontologie et d’Anatomie comparée of Paris’s Muséum national d’Histoire naturelle (MNHN) is the mecca of organismal anatomy, as their homepage describes. Georges Cuvier got the morphological ball rolling there and numerous luminaries were in various ways associated with it too; Buffon and Lamarck and St Hiliaire to name but a few early ones. It is easy to think of other contenders such as the NHMUK in London (i.e., Owen), Jena in Germany, the MCZ at Harvard (e.g. Romer) and so forth. But they don’t quite cut the dijon.

As today is John’s Freezer’s 7th blogoversary, and I was just at the MNHN in Paris snapping photos of their mecca, it’s time for an overdue homage to the magnificent mustard of that maison du morphologie. The exhibits have little signage and are an eclectic mix of specimens, but this adds to its appeal and eccentricity for me. I’ve chosen some of my favourite things I saw on exhibit on this visit, with a focus on things that get less attention (NO MESOZOIC DINOSAURS! sorry), are just odd, or otherwise caught my fancy. It’s a photo blog post, so I shall shut up now, much as I could gush about this place. I could live here.

Need plus-grand images? Clic!

Stomach-Churning Rating: 7/10 for some potentially disturbing anatomical images such as viscera, preserved bits, models of naughty bits etc.

Greetings. Note the stomach-churning rating above, please.

Right. We’ll get the amazing first view as one steps into the gallery done first. Mucho mecca. Anatomy fans simply must go here at least once in their life to experience it, and one cannot ever truly absorb all the history and profound, abundant details of morphology on exhibit.

Less-often-seen views from the balcony; one more below.

Indian Rhinoceros from Versailles’s royal menagerie; came to the MNHN in 1792.

Brown bear hindlimb bones.

Brown bear forelimb bones and pelvis.

Two baby polar bears; part of the extensive display of ontogeny (too often missing in other museums’ exhibits).

Asian elephant from Sri Lanka.

Lamb birth defect. Like ontogeny, pathology was a major research interest in the original MNHN days.

Wild boar birth defect.

Fabulous large Indian gharial skull + skeleton.

“Exploded” Nile crocodile skull to show major bones.

Let’s play name-all-the-fish-skull-bones, shall we?

Rare sight of a well-prepared Mola mola ocean sunfish skeleton.

Diversity of large bird eggs.

Asian musk deer (male), with tooth roots exposed.

Freaky gorilla is here to say that now the really odd specimens begin, including the squishy bits.

Freaky tamandua, to keep freaky gorilla company. Displaying salivary glands associated with the tongue/pharynx. These are examples of anatomical preparations using older analogues of plastination, such as papier-mâché modelling. I’m not completely sure how the preservation was done here.

Tamandua preserved head, showing palate/tongue/pharynx mechanism.

Chimp ears. Because.

Why not add another chimp ear?

Many-chambered ruminant stomach of a sheep.

Simpler stomach of a wolf. Not much room for Little Red Riding Hood, I’m afraid.

Expansive surface area of a hippo’s stomach; but not a multi-chambered ruminant gut.

Cervical air sacs of a Turquoise-fronted Amazon parrot.

Heart and rather complex pulmonary system of a varanid lizard.

It’s pharynx time: Keratinous spines of a sea turtle’s throat. All the better to grip squids or jellies!

Pharynx convergent evolution in a giraffe: keratinous spines to help grip food and protect the pharynx from spiny acacia thorns while it passes down the long throat.

Tongue/hyoid region of the pharynx of a varanid, showing the forked tongue mechanism.

Palaeontological awesomeness on the upper floor (the 2nd part of the gallery’s name). Here, the only Siberian woolly mammoth, I’m told, to have left Russia for permanent display like this. Frozen left side of face, here, and 2 more parts below.

Mammuthus primigenius freeze-dried lower ?left forelimb.

Skeleton that goes with the above 2 parts. It’s big.

But “big” is only relative- my large hand for scale here vs. a simply ginormous Mammuthus meridionalis; full skeleton below.

Four-tusked, moderate-sized Amebelodon elephantiform.

Naked woolly rhinoceros Coelodonta.

Extinct rhino Diaceratherium, with a pathological ankle (degenerative joint disease). I love spotting pathologies in specimens- it makes them stand out more as individuals that lived a unique life.

Glyptodont butt and thagomizer, to begin our tour of this business-end weaponry.

Eutatus leg bones, from a large fossil armadillo; Argentina. Really odd morphology; Xenarthrans are so cool.

Giant ground sloth (Megatherium) foot; ridiculously weird.

Giant ground sloth hand is full of WTF.

Metriorhynchus sea-crocodile from the Cretaceous: hind end.

Odobenocetops one-tusked whale that I still cannot get my head around, how it converged so closely on the morphology of a walrus.

Thalassocnus, the large marine sloth… few fossils are so strange to me as this one. But modern sloths swim well enough so why not, evolution says!

Rear end of the sea-sloth.

Megaladapis, the giant friggin’ lemur! Not cuddly.

A basilosaurid whale Cynthiacetus, one of the stars of the show, as the denouement of this post. Plan your visit now!