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Posts Tagged ‘dissection’

You know the drill- tell me what you can about this rather messy dissected specimen from The Freezers. What are the structures shown? Identification to genus/species level is probably not possible, but try to pin down the group of organisms it is from as tightly as you can:

Edit: This post had a Stomach-Churning Rating of 5/10. So you were probably safe anyway; if not, share your tale of revulsion in the Comments. 🙂

Edit edit: The specimen is revealing more here; this may or may not help:

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You behaved very well with the Mystery CT Slices #3; I was not lynched; so I can reward you for your exquisite mercy with another peering into the RVC’s Anatomy Museum. Yay! As promised, I will now present our fabulous collection of pre-dissected, preserved specimens.

Stomach-Churning Rating: 5/10; for dog lovers perhaps 7/10. I suppose I should enact this SCR system for all blog posts now?

First, a view down the main hall of dissected specimens (note nice blue carpet and bright green door? RVC likes colour sometimes.):

Next, some of those specimens, pertaining in particular to cranial appendages of the canine variety, in two adjacent shelving units (click to embiggen— all images in these posts tend to have substantially larger images you can view):

      

Zooming in on one such canine specimen, emphasizing the jaws and cranial nerves as well as larynx:

Next it would be apropos to reveal the inner anatomy of the jaw muscles (pterygoids!!! trigeminal nerve!) and neck/pharynx/CNS tissues:

And moving on to the upper part of dog necks and their associated muscles, nerves and other tissues that help support the head/larynx:

I would be remiss at this point if I did not show the main nervous system of a dog that runs from the head down to the rump:

Followed by the upper forelimb and lower hind limb dissections of humans’ best friend:

And now any dog lovers can stop panting and take a breather. Go for walkies?

I have horse feet to show instead:

Then I present you with a gorgeous corrosion cast from a mammal whose identity I am not certain of right now (will add later– sheep??) (EDIT: No, pig; a lung “triple cast”):

…and now a specimen that at first glance I thought was some sort of parasite, but the label tells the story (ID pending– cow/horse?from a pig):

Animal Inside Out/Bodyworlds doesn’t hold the monopoly on plastination; we do it too (I must remember to learn how to do this soon!):

Enough musculoskeletal system; I know you all come here for the guts, right? Goat stomach compartments (the reticulum region), as an exemplar of the famed (but inaccurately described) “four-stomach” digestive system of ruminant mammals- not 4 stomachs, but 4 compartments that divide the labour of digestion (including bacterial fermentation):

Bah, enough synapsids! Deep inside, every anatomist might secretly be coveting the dinosaurian digestive tract, here represented by a goose’s guts:

Since we’re really delving into the gooey bits now, how about the reproductive system of a hen, with a perspective across its ontogeny?

Dinosaurs, mammals; get over it! You and me, baby, we ain’t nothing but gnathostomes:

Like fish heads? Try shark brains (nice myosepta also evident here):

Whatever taxon floats your boat, the RVC’s Anatomy Museum has something for you, inside and out! Anyone still with me at this point can probably agree- we all heart anatomy:

Stay tuned for more Mystery CT Slices, museum tours (including a different museum, soon), and even more!

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Welcome to the first of a series of image galleries with highlights from the RVC‘s Anatomy Museum! Our veterinary school dates back to the 1789 epic dissection of the unbeaten racehorse Eclipse by surgeon Mr Charles Vial de Saint Bels, which led to the college’s founding in 1791 (incidentally, the RVC retains Eclipse’s skeleton to this day, and 80% of living racehorses come from Eclipse’s lineage!).

What, you didn’t know we have an anatomy museum? Well this is another of London’s many hidden museum treasures. It is based at our Camden campus, just a 10min jaunt from King’s Cross or St Pancras stations (or Mornington Crescent tube), in the colourful Camden Town neighborhood. It doesn’t have its own website, yet, and my posts are not intended to play that role, but I want to informally and unofficially celebrate its glory because I think we have a great museum full of wonderful features and people deserve to see them.

For example, when I first interviewed for (what became) my job at the RVC in 2003, one of the first sights at the Camden campus was the original, classic ~Victorian style (dark and gloomy, stained wooden cabinets, room chock full of skeletons) anatomy museum which presented the entrant with a lovely view of this:

Which sadly is my only photo of the skeleton of an Asian elephant that shows it in its original position, crowded next to the skeletons of a white rhino, common hippo, horse and other animals. If you know me and my penchant for giant critters, that was like being shown the Promised Land! Since then, modernity has required us to clear out the dusty Victorian room and rehouse the specimens in more airy, spacious surroundings. Which has worked out pretty well in our case, I think. Here is the elephant now, in the midst of our cafe next to our Anatomy Museum (sadly, the rhino and hippo are mostly now tucked away in storage, and no, there is no rhino horn here for people to steal. Sheesh!):

Much easier to walk around, drink coffee with, etc., and it has gained a second skull (with the skull of a baby also on display nearby). So you might immediately be able to see why I like our museum– any museum with a mounted elephant skeleton rocks, in my opinion. But also, I’m gradually cleaning up my freezer specimens, building a little museum of “my” own that will eventually become an official part of the RVC museum’s collection, so there is a connection to this blog too.

Anyway, here is what a visitor gets as a first impression upon entering our museum:

Namely, a horse who is less famous than Eclipse but still no slouch in his day, Foxhunter the show jumping horse, who won Britain its only gold medal at the Olympics 70 years ago (nice timing)! Then, looking around the museum, you will see:

A cow skeleton to your left, which is no shock at a vet school, but then look more closely, to the right:

A nice tiger skeleton is mounted there, with a pig skeleton atop it, and a hippo skull hanging out nearby (closer view of that in a later post). Through the green doors to the right is our lovely cafe, with the elephant and a few more specimens including a splendid mount of a sitting polar bear (to be shown later). And then, meandering around back to the left through the museum hall you will find:

A nice replica chimp skeleton next to a cast of “Lucy”, the famed Australopithecus early hominin! So there’s some decent evolutionary context in the exhibit, too; not just your standard domestic critters with little broader conceptual unification. But I think some of the museum’s greatest treasures  are the preserved specimens of lovingly dissected animal anatomy demonstrations, such as toward the back of the room:

These were done over past decades, many winning awards for the skill displayed in making them, and it is sad that this skill is becoming more and more rare, with shifts toward less hands-on, more computerized education and training. At least BodyWorlds and Animal Inside Out bucks this trend! It’s fortunate we have museums to show off the skill of preparators and dissectors so the beauty of such specimens can continue to be appreciated. I’ll show some closeups later.

There are plenty of surprises in the RVC’s Anatomy Museum, so if you get a chance and expect to be near our Camden Campus, come take a look sometime. Casual, unheralded visitors are not normally welcome, as the museum is more of an in-house educational resource than a public one. But I am told that scientists could easily get entry to study specimens on prior request, and with plenty of advance notice other members of the general public probably could, too. Mr Andrew Crook (recently awarded an MBE for his efforts using our museum and other facilities to educate local students) is the main contact person but please don’t swamp him with requests. It would be best to contact me first for advice and contact details.

So there’s a little introduction to our Anatomy Museum, and coming posts will show you more of the cool specimens within– stay tuned!

I’ll have our friend the ostrich skull show you the way out–

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Well, I’ve been pretty busy with grant-writing and other stuff lately, so I’ve been neglecting my beloved blog. Here is a little sequel to my Animal Inside Out exhibit review, from my 2nd visit there, yesterday. I had previously missed the “3-headed camel” that is in one corner of the great hall (the Diplodocus one overlooked by Darwin). Because that is outside the special exhibit, there are no issues with taking photos, although I must apologize that as usual I just had my mobile phone’s camera. So here you go– a camel anatomy extravaganza. Too bad I didn’t do this on Hump Day

(beefy reward at end for those who view all the pics)

Front view.

Side view.

Back right view. Naughty boy trying to grab the guts. It’s not a petting zoo, kid!

Back view. Kid nearly has snatched some precious entrails.

Front right view.

Cranial view of forelimb. Now I’m starting to get pretty interested in documenting the muscle anatomy for my own records. These AIO displays really do clearly show the myology.

Nice view of right triceps, latisssimus, carpal extensors/flexors, etc.

Guts, glorious guts! Beautifully sectioned stomach, showing “pseudoruminant” three-chambered structure and smaller compartments within.

Right hindlimb, rear/side view. Great view of semimembranosus/tendinosus, biceps femoris, superficial gluteal, tensor fasciae latae?

Left distal hindlimb, side view, emphasizing (toward bottom right) calcaneal “Achilles” tendon, and possibly a slip of the very reduced plantaris muscle? Also distal tendon of hamstrings prominently visible, with belly toward top of image (dark).

Left forelimb, showing elbow region with triceps/anconeus, more carpal flexors/extensors.

Great exhibit. No bullshit.

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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!)

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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!!!)

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A superficial little post for you today, with a skinny specimen from the freezers. What is it, what/where from, etc; tell me what you know about it!

(upper object, not the ruler…)

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Like other birds, ostriches are fluffy. Too fluffy for some anatomists– so fluffy, it’s hard imagining or estimating what they look like beneath all the feathers. A few years ago, we received an ostrich from a UK farmer. The male bird had been killed by a kick to the neck from another rival, and at the time was supposedly “Britain’s largest ostrich.” As the feathers were valuable to him, the farmer delivered the animal to us whole but plucked. I wanted to dissect it mainly to refresh my memory on ostrich anatomy while developing a biomechanical model of their limbs (see below). Taphonomy expert Jason Moore then buried it for his studies of how bodies decompose.

[Side note: ostriches and other ratites (flightless birds, members of the palaeognath group, whose evolution remains fascinatingly complex) are often brought up as uniquely dinosaur-like. That’s rather misleading; all birds are living dinosaurs, so all birds are descended from an ancestor that was equally ‘dinosaur-like’. What we see of them today is a snapshot that is biased by their recent evolutionary history. During their apparently multiple losses of flight, ratite birds increased in body size and “re-evolved” (or simply enhanced) some traits that were more marked in extinct dinosaurs than in the most recent common ancestor of living birds. Some of those more ‘primitive’ traits may be due to flightlessness, some due to large size, some due to their extreme running specializations; science hasn’t sorted all that out just yet. But the point is, ostriches and other ratites are far from the ancestral form that all birds sprung from, which was probably more like a small, flying tinamou-like animal. Their similarities are due to convergent evolution. And they’re still quite different from something like an “ostrich-mimic” dinosaur- which is a sad misnomer because it’s more that ostriches mimicked (in a naughty teleological sense) ostrich-mimic dinosaurs like Struthiomimus than the other way around; the ornithomimosaurs did it first (Huzzah!). Ratites have just gone back, in some ways but not others (e.g. no long tail or large arms) to a superficially more primitive body form. There have been some wacky ideas to the contrary before, such as the idea that ratites evolved entirely separately from other living birds from different dinosaur stock, but they’re so discredited now by multiple lines of evidence that I won’t glorify them by spending time discussing each. This tangent has gone on too long and must die.]

Anyway, back to the plucked ostrich in question. My first look at it really stunned me. It was a powerful example of just how ‘dinosaurian’ most of the anatomy of living birds is, for reasons noted above. I’d never seen a naked ostrich and now I’ll never look at them the same again. Maybe you won’t, either…

First, some images of the animal once it was brought into our dissection room (which you might recognize from the great Inside Nature’s Giants documentary).

The device near the top of the screen is a digital scale; we were weighing the bird before we cut in…

Close-up view of the hugely muscular legs (each leg is around 25% of the animal’s body weight, and mostly muscle; about 50% more bulky than our legs), and the arms (shown more below).

129 kg weight sans feathers; not bad! That’s about 284 pounds for those folks still mired in the medieval Imperial system of units. 🙂

The swollen, bloody region just below the head (on the left above) is where the mortal blow struck. Ouch!

I love the hands of ratite birds. Yes, those are little claws attached to the three vestigial fingers (thumb/first finger at top, long middle finger, and tiny third finger bound to it). Darren Naish covered some of this in a previous post, and let’s not forget SV-POW’s excellent series of “things to make and do” involving various critters including ostriches.

Ostriches and I go way back. Here I am from my less bald immature postdoctoral days at Stanford University in 2002, dissecting a smaller (female, 65kg) ostrich for some biomechanical modelling (still mostly unpublished; aaargh!).

And yes, I had a third hand back then; later lost during a tragic dissection incident involving a battleaxe and a bottle of tequila. I don’t want to talk about that.

Ostrich packed for transport. Just barely fit in the trunk of my little 1993 Toyota Tercel (R.I.P.)!

Once we complete dissections. we put everything together in some fancy biomechanical computer models (a subject of a future post), resulting in a nice, 3D,  poseable, anatomically-realistic model of the entire limb musculature, shown above. This is a right hindlimb in side view, with the individual muscle paths abstracted as red lines. More about this when it is finally published…

This is just a teaser showing off some of the cool external anatomy of ostriches-in-the-buff, and what we’ve done with the anatomical data we’ve gathered. I’ll do a post later showing what’s inside, which is also pretty amazing. Hope you enjoyed it!

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Good morning, Freezerinos! Here is a twin treat for you to puzzle over. Two things, perhaps rather squidlike at first glance, but not cephalopods. There is a conceptual connection between the two images. Can you identify both of these structures? Huge bonus points if you can identify the taxon they belonged to, but stabs at it are encouraged; there are clues in the images…

(labels have been removed to protect the innocent)

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Without further ado, what’s up with this specimen from The Freezers? What is it, what animal etc?

 

(admin note, 28 Oct 2012: Mystery Dissections 2-3 do not exist, mysteriously. At the time, in the jumbled freezers of my mind, they corresponded to Mystery CT Slice(1) and Mystery CT Slice 2. But we can pretend that MD2-3 are just an eternal mystery of this blog, subject of numerous conspiracy theories that you are welcome to expound upon!)

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