Posts Tagged ‘Rhinos Matter’

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!


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Today, to help thaw you poor Americans out of that Arctic Vortex, we have a guest post bringing the heat, by my PhD student Sophie Regnault! This relates to some old posts about rhinos, which are a mainstay here at the WIJF blog- I’ve posted a lot about the rhino extinction crisisfeet, skin, big and bigger bones, and more, but this is our first rhinoceros-focused, actual published scientific paper! Take it away, Sophie! (We’re planning a few more “guest” blog posts from my team, so enjoy it, folks!)

Almost a year ago to the day, I submitted my first paper written with John Hutchinson and Renate Weller at the RVC and it has (finally!) just been published. To celebrate, I have been allowed to temporarily hijack ‘What’s in John’s Freezer?’ for my first foray into the world of blogging. I started the paper back as an undergraduate veterinary student. It was my first experience of proper research, and so enjoyable that I’m now doing a PhD, studying sesamoid bones like the patella!

We wanted to discover more about the types of bony disease rhinos get in their feet, of which there isn’t much known. Rhinos, of course, are big, potentially dangerous animals – difficult enough to examine and doubly difficult to x-ray clearly because of their thick skin. Unlike diseases which are fairly easy to spot (like abscesses or splitting of the nails and footpad), there is hardly anything out there in the scientific literature on bony diseases in rhino feet. It’s no small issue, either. When your feet each need to support over 900kg (typical for a large white rhino), even a relatively minor problem can be a major pain. Progressing unseen under their tough hide, lesions in the bone can eventually become so serious than the only solution is euthanasia, but even mild conditions can have negative consequences. For example, foot problems in other animals are known to have knock-on effects on fertility, which would be a big deal for programs trying to breed these species in captivity.

Hidden treasures abound!

Hidden treasures abound! (Photos can be clicked to embiggen)

Data gathering was a blast. I got to travel to Cambridge, Oxford, and London during one of England’s better summers, and these beautiful old museums were letting me snoop around their skeleton collections. I’d been there often as a visitor, but it was anatomy-nerd-heaven to go behind the scenes at the Natural History Museum, and to be left alone with drawers and drawers of fantastic old bones. Some of the specimens hadn’t been touched for decades – at Cambridge University Museum of Zoology, we opened an old biscuit tin filled with the smallest rhinoceros foot bones, only to realise they were wrapped in perfectly preserved 1940’s wartime Britain newspaper.

rhino-feet (2)

rhino-feet (4)

rhino-feet (3)

Osteomyelitis… (3 clickable pics above) the toe’s probably not meant to come off like that!

In addition to my museum studies, I had another fun opportunity to do hands-on research.  John (of course!) had freezers full of rhino legs (looking disconcertingly like doner kebabs, but maybe that’s just me!), which we CT scanned to see the bones. Although it is a pretty standard imaging technique, at this point I had only just started my clinical studies at the vet hospital, and being able to flick through CT scans felt super badass. Most vet students just get to see some horse feet or dog/cat scans, at best.

Another osteomyelitis fracture, visible in a CT scan.

Another osteomyelitis fracture, visible in a CT scan reconstruction.

We expected to find diseases like osteoarthritis (a degenerative joint disease) and osteomyelitis (bone infection and inflammation). Both had previously been reported in rhinoceroses, although it was interesting that we saw three cases of osteomyelitis in only 27 rhinos, perhaps making it a fairly common complication. It’s an ugly-looking disease, and in two of the cases led to the fat, fluffy bones fracturing apart.

We also had several unexpected findings, like flakes of fractured bone, mild dislocations, tons of enthesiophytes (bone depositions at tendon/ligament attachments) and lots of holes in the bones (usually small, occasionally massive). For me, writing up some of these findings was cool and freaky paranoid in equal measures. They hadn’t been much described before, and we were unsure of their significance. Was it normal, or pathological? Were we interpreting it correctly? Discussions with John and Renate (often involving cake) were reassuring, as was the realisation that in science (unlike vet school at the time, where every question seemed to have a concrete answer) you can never be 100% sure of things. Our study has a few important limitations, but has addressed a gap in the field and found some neat new things. Six months into my PhD, I’m enjoying research more than ever, and hoping that this paper will be the first of many (though I promise I won’t keep nicking John’s blog for my own shameless self-promotion if that happens!  EDIT BY JOHN: Please do!).

Nasty osteoarthritis wearing away the bone at the joint surface. Most cases occurred in the most distal joint.

Nasty osteoarthritis wearing away the bone at the joint surface. Most cases occurred in the most distal joint.

Deep holes in some of the bones: infection, injury?

Deep holes in some of the bones: infection, injury?

The paper:
Sophie Regnault, Robert Hermes, Thomas Hildebrandt, John Hutchinson, and Renate Weller (2013) OSTEOPATHOLOGY IN THE FEET OF RHINOCEROSES: LESION TYPE AND DISTRIBUTION. Journal of Zoo and Wildlife Medicine: December 2013, Vol. 44, No. 4, pp. 918-927.

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A quick plug here for BBC Radio 4’s fourth episode of “Just So Science”, playing at 13:45 GMT today (this is the link). I was interviewed a few weeks ago for the show “How the Rhinoceros Got His Skin,” a la the classic Kipling tale. This series is revisiting Kipling’s tales in light of modern evolutionary science and evidence, whereas Kipling only had crude, Lamarckian or early Darwinian insight. Check out their earlier episodes on whales, leopards and armadillos– good stuff, and with real scientists.  Richard Dawkins may appear again (EDIT: yep! Dawkins manifested) in this episode to provide some gravitas and evolution street cred, too.

And Freezersaurus gets a big plug! From the website: ” Rhinos and horses have much in common. John Hutchinson studies both, but just don’t ask to look inside his freezer.” 🙂  NOTE: I am not a vet (I am a biologist), and definitely not a horse specialist like others in our lab, but I do study horses a little, in a comparative context.

While the original Kipling story focuses on rhino skin, and the producers were interested because of my popular post here on rhino skin, we discussed other issues such as gait, fossil record, feet, and more. I owe thanks to rhino skin expert Dr Tobin Hieronymus for helping me bone up on the unusual skin of rhinos, which has a surprising amount in common with the tough hide of walruses, boars, some water deer, and a few other species. It’s not just normal thickened skin, as Tobin and others have shown. Anyway, I don’t want to give away what’s on the radio programme; afterwards I might embellish this post more with some rhino anatomy and mechanics facts.

Coincidentally, I’m receiving four white rhinoceros feet today from a zoo mortality. So it’s rhino-fest here!

I hope you like the show— please let me know what you think in the comments below! I really enjoyed listening to it, but I’d like to know what you thought.

White rhinoceros forelimb (left), ready for dissection.

White rhinoceros forelimb (left side), ready for dissection.

How did the rhinoceros get her foot tendons?

How did the rhinoceros get her foot muscles?

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In case you haven’t heard, Saturday, September 22nd, 2012 (today, at this writing) is World Rhino Day! The main websites include here and here.  Ivan Kwan has also posted a fantastic blog entry “Rhinos are not prehistoric survivors” for WRD2012- check it out! And if you haven’t seen the WitmerLab’s AWESOME Visible Interactive Rhino site, you really really need to (in fact, quit reading this and go there first; it is soooooo good!).

I’ve written about the global rhino crisis before, and about rhino foot pathologies. The title of today’s post may be “cute”, or at least goofy, but the real situation is as grim as the images I’ll share. I won’t repeat the explanation, but all five living species of rhinoceroses are in serious trouble. There’s a good chance that most or all of them will go extinct quite soon– see the previous links for more information on this. Javan and Sumatran rhinos are dangling the most precariously over the precipice of extinction. My goal in this post is to share the beautiful, complex and exotic anatomy of rhinoceros anatomy and movement, and the joy of contributing new scientific information about poorly understood species.

Stomach-Churning Rating: 7/10— dissections, and there are a couple of pics where the specimens are not so fresh, and there’s big skin, and a huge heart.

Baby white rhinoceros. Will frozen specimens like this be all we have of rhinos someday?

The purpose of today’s rhino post is to share a bit more; especially images; of the work my team has done on rhinoceros gait and limb anatomy; all of it unpublished but hopefully coming soon. We’ve steadily been collecting data since ~2005. Because my previous post went through some of this, I’ll keep it brief and image-focused.

First, a video of one of our amusing encounters with a white rhinoceros, at Woburn Safari Park. In this study, we wanted to measure, for the first time really, the gaits (footfall patterns) that a white rhinoceros uses at different speeds, and how often it uses those different gaits. We attached a GPS unit on a horse surcingle around the rhino’s torso, which measured the animal’s speed once a second. We then observed 5 individuals (1 at a time over various days), following them in my station wagon (estate car) across the safari park. We filmed them with a conventional camcorder to document their gaits, and concentrated on the two periods of the day that they’d normally be active: when released from their overnight barn, and when coming in for the night back to that barn. They got rather excited and frisky some of those times. The GPS belt then kept recording speeds for the rest of the day; unsurprisingly, the rhinos generally did not do much. I have to thank Nick Whiting, rhino handler, for his help making this research happen. I’ve been meaning  for too long to finish the final paper… soon, I hope! Enjoy this tense scene of a rhino investigating my car (driven by me and with an undergraduate student filming) then having a nice canter/gallop across the field (accompanied by my jubilant narration).

Like our foot pressure research, we aim that this work provides baseline data useful to caretakers of rhinos; for example, to test if a particular animal is lame. This follows what we’ve successfully done with elephant gaits and feet, translating basic research into more clinical application. But my major scientific interest is in understanding more about what makes any rhinoceros, even a 2-tonne White rhino, so much more athletic than any elephant (even a baby or 2-tonne small adult Asian elephant). As the video shows, they can use a variety of gaits including cantering and galloping, and trotting at slower running speeds. No elephant ever does that, and no one knows precisely why. The leg bones are more robust, but the muscles aren’t that dramatically larger in rhinos.

An Indian rhinoceros forelimb- note the characteristic knobbly hide, unlike the smoother, more elephant-like hide of a White rhinoceros.

Similarly, the anatomical work we do with rhinos is intended to not only be useful science for comparative biologists like me, showing how rhino limbs work and how they differ from those of other animals, but also to aid clinicians in comparing normal vs. pathological anatomy. For conveying that anatomical work, I’m lucky to have been granted permission to use a professional photographer’s pictures of some of my freezers’ rhino specimens– big thanks to James King-Holmes and the Science Photo Library. The watermarked images below belong to them. I ask that you do not use them elsewhere, honouring their license to me for personal usage on this website (and I will only use them here). I’m in all the images, which makes me feel weird putting them up here, but it’s about the rhinos (and freezers), not me. First: the infamous “rhino foot freezer”, featuring some of its denizens:

Second, a re-introduction to multifarious contents of Freezersaurus, but this time featuring rhino feet (here, a skinned white rhino foot that we had already studied):

…and inside we go (and I begin to get frosty and numb-fingered from holding a foot; my smile soon fades):

Taking a rest with the skinned white rhinoceros foot:

And now warming up at the “digital freezer”, our CT scanner, and preparing to scan another rhinoceros foot, which segues nicely out of this image sequence:

Now over to some 3D anatomy– segmented reconstructions of rhinoceros fore (top) and hind (bottom) feet, from CT scans; if you’ve frequented this blog you know the drill. Here, the longest bones are the metacarpals/metatarsals and the upper bones are the carpals/tarsals, then the bones near the botttom are the phalanges, which connect to the hooves (visible in the bottom image):

I’ll wrap up with a series of images of basic limb muscle anatomy from dissections we’ve done of baby and adult Indian and White rhinoceroses. First, here’s what a rhino looks like underneath the skin:

But ahh that skin, that fabled “pachyderm” skin! A rhino’s greatest defense is also a real chore to get through in a dissection.  Here, we enlist the help of a crane and hook, hurrying to get down to the muscles of this forelimb before rotting takes over too much (as with other big animals, this is a tough race against time even in chilly England!):

Here is a closer look at that amazing armoured skin; sometimes 10cm or so thick:

Back to the forelimb muscles– stocky and well-defined for this athletic animal:

(late addition) Here are the massive shoulder muscles, such as the serratus and latissimus dorsi (this is a left limb in side view; head is toward the left):

And now a close look at the forearm muscles:

And then over to the hindlimb, here from an adult Indian rhino, whose thigh bone (femur) shows the characteristic giant “third trochanter” (toward the bottom centre of the image), which is an expanded bony attachment for the giant “gluteobiceps” muscle complex that retracts the femur for the power stroke in locomotion. Also, this specimen showed fascinating anatomy that I’d never seen before: the third trochanter has a thin bar of bone that extends up (toward the bottom left in the image) to fuse with the greater trochanter, opposite the head of the femur (upper left corner):

Damn my photography skills, cutting off the edge of that image and instead giving a view of my boots! Anyway, another interesting feature of that femur: the medial (inner) condyle of the femur (knee joint surface) has a pink stripe of worn cartilage. This is indicative of at least a moderate stage of arthritis, shown here (look for the pinkness amidst the shiny, healthy white cartilage on the upper right side). It is an exemplar of serious welfare problems that some captive, and probably some wild as well, rhinos face:

(late addition) Back up the limb, this baby White rhino shows the massive thigh muscles, especially that “gluteobiceps” that attaches to the third trochanter, noted above, and also showing the hamstrings:

Moving down the limb, we encounter the glorious three-toed perissodactyl foot of rhinos, and the robust hooves/nails, which are reasonably healthy in this animal– unlike others I’ve seen:

And the sole of that foot, showing a fairly healthy pad, below. Toward the rear (away from the nails), it culminates in a modest-sized fat pad, or digital cushion, akin to that in elephants but far less well developed and lacking the false “sixth toe” (predigit) (see also CT scan movie of the hindfoot above):

Here’s a view inside that marvelous foot, showing the HUGE digital flexor tendons. These help support the toes against gravity and, in theory, can act to curl them up– although in a rhino’s foot, as in an elephant’s, the toes are more like a single functional hoof, with reduced independence compared to a carnivore or primate:

And that ends our tour of rhinoceros limb anatomy and function. Help spread the word of how precious and threated rhinos are; educate yourself and others! And if you overhear someone talking about using rhino horn for medicine, try to politely educate them on the utter fallacy of this tradition. It is this cruel, greedy, ignorant practice that needs to die; not rhinos. I don’t enjoy receiving dead rhinos, on a personal level, even though the science excites me. I’d rather have many more alive and living good, healthy lives. And my team is trying to do what we can to help others on the “front lines” of rhino conservation make that happen.

For example, Will Fowlds, vet and co-owner of Amakhala Game Reserve, South Africa, recently sent us some images of a white rhino that had been caught in a poacher’s foot snare some years ago. The poor rhino still was having problems healing– we inspected x-ray images and external photos and helped to make an initial diagnosis of osteomyelitis, a nasty infectious, inflammatory foot bone/joint disease. We are following this case to hope that the rhino recovers and contribute help where we can, but the tough job belongs to the keepers/vets on the ground, not to mention the rhinos…

Furthermore, we’ve done foot pressure research covered here, and here is an example of the data we’ve collected (image credit: Dr Olga Panagiotopoulou), showing high pressures on the toes and low pressures on the foot pads:

Big thanks to people on my team that have helped with this and related research: Dr Olga Panagiotopoulou (and Dr Todd Pataky at Shinshu University, Japan), Dr Renate Weller in the VCS Dept at the RVC, Liz Ferrer at Berkeley, and former undergraduate student researchers Sophie Regnault, Richard Harvey, Hinnah Rehman, Richard Sheehan, Kate Jones, Bryony Armson and Suzannah Williams.

A White rhino’s heart, with more images below, all courtesy of William Perez’s Veterinary Anatomy Facebook pages. A mass of around 10kg (22 lbs weight) is not unusual! (Compare with even larger elephant heart)

White rhino closeup: coronary arteries

White rhino: branches of left coronary artery

White rhino heart: right atrium

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Well, I happened to take some more photos of a few of my favourite skeletons/bones from our Anatomy Museum during my last jaunt over to our Camden campus, and figured I might as well share them. So here you go! (Right now it’s so hot I wish I was a skeleton! Gigantothermy is not always so great) First, two views of our seated polar bear, which I learned this week is a celebrity— a model for the kickass armoured polar bears in the film The Golden Compass:


Then, also out in our cafe area you’ll find some nice smaller specimens in addition to our elephant. Such as:

A decent mount of a three-toed sloth is above; and below I’ll share several skulls including a second hippo (male? quite different morphology from the other one I showed):

And another charismatic megafauna, a ?black? rhinoceros (shown previously as a mounted skeleton in our old hall):

And a small gharial (Gavialis) skull:

Which can be nicely juxtaposed with a more robust Caiman (or our earlier Alligator):

And then a small wallaby:

Let’s go back inside. I have a few more friends for you to meet. Such as our chimp next to a Lucy skeleton (both casts), briefly glimpsed in my first post:

And a really, really gnarly-faced bulldog! Shudder.

During my brief perusal of the exhibits the other day, I realized I had never shared our nice knee joint dissection in my post on those specimens, nor had I included it in my knotations about knee joints. This is particularly egregious as I am now doing a year-long fellowship/sabbatical to study knee joints, in particular the patella (kneecap) of birds. Here, a dog, with helpful labels of the anatomy around the stifle:

And that’s all folks! I’m preparing a particularly wacky post for later, which will include lots of whimsical anatomy, so stay tuned and keep coooooooool!

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Well, here we are at the end of our virtual tour of the RVC’s little-anatomy-museum-that-could. Soon we will return to our regularly scheduled programme of dismembered cadavers and frozen body segments. I know you’ve missed them.

This post has a Stomach-Churning Rating (SCR) of 2/10, unless either penis bones or the backs of knees really gross you out (then maybe 4/10 at worst, although there is a link hidden in the text that might really freak you out).

OK, here we go. You might remember this chap, the famed racehorse Foxhunter:

And the museum features sundry other domestic-type species and their close kin, such as this sheep (a Soay Ram):

And this skeleton that is probably also a sheep, unless it is a tricky goat (notice framed photo of Bodyworlds exhibit on wall):

As well as his barnyard buddy, a quite robust pig:

But I want to focus more here on the surprises that the museum’s collection of skeletons has to offer, like this tiger poised below the pig:

Along with a wide assortment of smaller mammals such as this kinkajou coatimundi (note: label is wrong; see this Twitter chat we had that solved this mystery):

And a rhesus monkey (our primate skeletal collection is not shabby at all!):

And a whole shelf of ossified dog (and other carnivore) penises, oh joy! (os baculum; the “penis bone” of various Primata, Rodentia, Insectivora, Carnivora and Chiroptera– the infamous mnemonic P.R.I.C.C. of comparative anatomy):

But, great as penises may be and much as the internet may love them, there is much more to see here. Carry on reading, or incur the wrath of the giant fossil walrus baculum [oosik]! (this, Freezerinos, is called an argument ad baculum, I have just discovered; had to share!)

As I mentioned way back in my first post, what really sold me on the museum when I first viewed it back in 2003 was the megafauna! Here’s a photo I dug up of how the rhino used to appear in the museum’s old settings:

And the hippo was close by:

My off-with-their heads bias rears its ugly cranial appendage here, but I’ve already shown you its skull, so rest easy craniophiles; you had your day of glory. It’s time to kneel before Zod, or in this case kneel before my collection of animal knee photos! I hate to remind you of the trauma, but I did promise this with the mystery emu knee dissection, so suppress your PTSD [knee TSD?] and come along quietly now… Let an elephant knee soothe your tortured soul (from here on, all knees are left knees, in caudal/rear view):

I’m going to continue on without providing longwinded interpretations. I’ll leave you to draw your own, and just enjoy the diversity of knee anatomy, with some surprises toward the end. Descending in the size scale from multi-tonnes to semi-tonnes, first, a rhino:

And then our hippo:

The RVC does not have a mounted giraffe skeleton but I can show you the knee from our dissections, now nice and tidy (note the absence of a fibula, reduced to a small tarsal (ankle) bone in many artiodactyls– but not pigs or hippos as you can see above; what consequences this change has for knee joint mechanics is entirely unknown! However, the fibula has such a small/nonexistent connection to the femur/knee joint in many large mammals that the consequences may be negligible; who knows.):

Now, a horse of course:

One reason I find knees so fascinating scientifically is that they are mechanically so complex (and often over-simplified as simple hinges) and yet so fragile (knee injuries are common in many species; poorly adapted humans in particular! To wit…). But I also love knees because they feature prominently in discussions of form and function in extinct animals; in particular, dinosaurs. Let’s not forget Scrotum humanum, either…

Consider a few representative dinosaur images (mostly from the AMNH; not RVC!) here, starting with my old pal Tyrannosaurus (sorry, dislocated knee in this mount; ouch!):

Now, a ceratopsian (probably Triceratops??), I think; photo-labelling fail! Could easily be some sort of hadrosaur or something, though:

For what its worth, sans massive cartilages, a sauropod knee to round out the holy trinity of Dinosauria:

Consider here how the fibula plays a greater role in the dinosaurian knee joint (as in birds, too, to some degree), compared with the mammals above. But also consider the whopping amount of soft tissues missing here, as made evident in the emu post. Daunting indeed.

We kneed to know more about knees before we can knavigate their aknatomy and make knew iknfereknces about their fukntiokn! And so I’m coming back full circle to my earlier anatomical studies this year to look more closely at knees in a variety of species; more about that later.

And that’s the end. I hope you liked the kneet photos and knurture the kneed to come back for my knext post, which will kontain more knormal spellikng.

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