Dodo monograph cover - Claessens et al 2016

Here’s an awesome thing that just landed in my mailbox: the new monograph on the Thirioux dodos by Leon Claessens and his collaborators. They’ve done a better job describing what’s cool about these specimens than I could, so for the rest of this post I’m just borrowing their text from the Aves3D site, where you can view 3D models of whole dodo skeletons and many individual elements (not to mention zillions of elements from lesser, non-dodo birds):

The dodo (Raphus cucullatus) skeleton on exhibit at the Durban Natural Science Museum is one of two unique skeletons discovered and assembled more than a century ago by the amateur naturalist Etienne Thirioux. Thirioux’s two dodos are unique, not just because they are the most complete skeletons in existence, but also because they are the only two skeletons comprised of the bones of either a single individual bird (the Port Louis dodo), or the bones of (only) a few different birds (the Durban dodo). In contrast, all other known dodo skeletons are incomplete and are typically put together from separate fossil bones uncovered at a marsh called the Mare aux Songes.

Port Louis dodo skull - Claessens et al 2016 figure 6

Port Louis dodo skull – Claessens et al 2016 figure 6

The Thirioux specimens contribute greatly to our understanding of the anatomy of the extinct dodo and are the subject of a new, major monographic treatise:

Anatomy of the dodo (Raphus cucullatus L., 1758): An Osteological Study of the Thirioux specimens.
Leon P. A. M. Claessens, Hanneke J. M. Meijer, Julian P. Hume, and Kenneth F. Rijsdijk (Editors).
Society of Vertebrate Paleontology Memoir 15, Journal of Vertebrate Paleontology Vol. 35, Supplement to No. 6.

We are pleased to make the Thirioux dodo skeletons available to the public for viewing on Aves 3D and Sketchfab. Please enjoy these wonderful scans of the skeleton of a fascinating bird, and check back on the site frequently, as we continue to upload more new dodo bone scans each week.

Sincerely,
Leon Claessens
for the Dodo Research Programme and the Aves 3D team

Congratulations, Leon and team, on a landmark publication. And thanks for all the free dodo visualizations!

For previous dödö-related musings, please see this pöst.

Port Louis dodo skeleton - Claessens et al 2016 plate 1

Port Louis dodo skeleton – Claessens et al 2016 plate 1

The pheasant comes apart

March 26, 2016

A couple of weeks ago, I was given a pheasant, which I reduced to science and food. When we last saw it, it was down to a skinned and partially defleshed head/neck and feet. It’s been through a couple of defleshing rounds since then, and today I was able to take it fully apart:

2016-03-26 12.31.09

At the moment, the bits are laid out on this plate, drying. Small amounts of soft-tissue remain (and more on the second foot), which may need the attentions of invertebrates to fully clean.

It pains me to admit, but even though I have kept the cervical vertebrae, for most people the skull will be the interesting part. Here it is in a little more detail, disarticulated into about ten units. The mandible is to the right of this image; the rostrum to the left of it, and the main cranial section to the left again:

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To the sides are the bones that laterally connect the rostrum to the braincase: zygomatics, quadrates and what have you. They are laid out roughly in the right positions, though the two quadrates may have been switched. Once everything is clean and dry, I’ll glue it back together, using my ostrich skull to help guide me.

The feet are trickier. Here’s the one I took apart:

 

2016-03-26 12.31.35

At the top of the photo, you see a mass of ossified tendons, which operated the toes from more proximal areas. This is how all bird feet work, and it’s such a great scheme that it seems weird everything doesn’t do it.

Below these, we have the tarsometatarsus to the right, and the four digits to the left. Each digit has its phalanges in the right order, but I don’t know what order the digits themselves should be in. To help me get that right, I pulled out of prepping the other foot down, hence its current semi-zombified state:

2016-03-26 12.31.23

I’m hoping it’s still intact enough to guide me as a reassemble the bones of the other foot. (Once that’s done, I may also take this one to completion, or I may decide that one pheasant foot is enough.)

Anyway, it’s nice to be progressing this specimen. Next, I need to figure out the best way to decapitate a medium-sized mammal (like a fox or badger) without damaging the skull, and using no special equipment.

I was relaxing on the Sunday afternoon before last, when there was a knock on the door. A couple of friends of mine had popped round with a plastic sack containing a fox and a pheasant that they’d found. (They rightly pointed out that it sounded like a pub.)

The fox is a treat for another day. Here’s the pheasant:

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(Don’t judge me on the state of our kitchen floor — that’s not important right now.)

It was 86 cm long from beak to tip of the tail-feathers, and massed 1393 g. The wingspan was hard to measure, because the wings want to pull back in towards the torso, but my best estimate is 73 cm.

Here’s the right wing extended:

2016-03-06 16.03.58

Shamefully, I’ve not really played with a dead bird before, so it was a new experience for me to feel how astonishingly unmuscled the wings are. There’s nothing there but skin, bone and feathers. The wings are of course operated by tendons, which are powered by the massive breast muscles — something that shouldn’t be surprising since (A) it makes mechanical sense to concentrate the muscles near the centre of mass, and (B) everyone knows birds do this with their hindlimbs, hence the ridiculously thin legs of flamingoes.

I had planned to do a Brodkorb (1955) on the pheasant: plucking it and weighing the feathers; then skinning it and weighing the skin; then eviscerating it and weighing the viscera; and so on. turns out that this is a lot harder than it sounds. I physically couldn’t pull the feathers out of the wings, for example. After a not-very-long struggle, I gave up and pulled off the skin and feathers together.

Here’s the nude bird, looking like a dinosaur. (Who’d have guessed?)

2016-03-06 16.28.08

Note the very distinctive and knobbly fatty deposits.

At this stage, since my Brodkorb-style teardown was a bust, I thought we might as well eat the parts of the pheasant that I didn’t want for science. So I trimmed off the breasts — you really get a sense of how massive the flight muscles are when you do this for a bird that started out intact — and the legs:

2016-03-06 16.48.05

These fried up nicely — though they were hard to photograph through the steam:

2016-03-06 20.13.19

The breasts were very tasty, more like pork than chicken in both flavour and texture. The legs were much tougher to deal with — it was hard to get the meat off them. Still a good flavour, though.

I’d removed the head-and-neck assembly, and the feet, for science. Once I’d removed the guys, I thought I’d simmer the rest of the carcass for stock, but once that process had been under way for quarter of an hour or so, I had to admit that it was smelling of poo. I assume I’d not removed the guts sufficiently. I admitted defeat and tossed the carcass in the trash.

Then I gently simmered the head/neck and feet for an hour or two. Here’s how they looked (and check out how the yellow fat deposits have congealed into nodules):

2016-03-07 13.07.50

What’s that? You want a close-up? Sure!

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And one of the feet?

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Those spurs are nasty!

Anyway, I picked off what flesh I could from the head/neck, and peeled away the scaly skin from the legs and some of the toes:

2016-03-07 13.20.15

I’ve not peeled all the toes, because once that’s done only cartilage keeps the phalanges articulated, and that will come away with more simmering, leaving me with a jigsaw puzzle. The plan now is to keep one of the feet in its relatively intact state and skeletonise the other. Then I can use the whole one as a key to reassemble the bones of the other.

The skull, of course, I will continue to deflesh. More simmering will be needed before I can proceed. After a couple more iterations, I’ll put the skull out under a cage for invertebrates to clean up the remaining shreds of soft-tissue, before rinsing, cleaning, degreasing and drying.

Further bulletins as events warrant.

References

  • Brodkorb, Pierce (1955). Number of feathers and weight of various systems in a Bald Eagle. The Wilson Bulletin 67(2):142.

Liem et al 2001 PPTs - intro slide

Functional Anatomy of the Vertebrates: An Evolutionary Perspective, by Liem et al. (2001), is by some distance my favorite comparative vertebrate anatomy text. When I was a n00b at Berkeley, Marvalee Wake assigned it to me as preparatory reading for my qualifying exams.

This scared me to death back then. Now I love it.

This scared me to death back then. Now I love it – sharkitecture!

The best textbooks, like Knut Schmidt-Nielsen’s Animal Physiology (which deserves a post or even series of its own sometime), have a clarity of writing and illustration that makes the fundamentals of life seem not only comprehensible, but almost inevitable – without losing sight of the fact that nature is complex and we don’t know everything yet. FAotV has both qualities, in spades.

Where vertebrae come from.

Where vertebrae come from. Liem et al. (2001: fig. 8.4).

I’m writing about this now because Willy Bemis, second author on FAotV, has just made ALL of the book’s illustrations available for free on his website, in a series of 22 PowerPoint files that correspond to the 22 chapters of the book. All told they add up to about 155 Mb, which is trivial – even the $5 jump drives in the checkout lanes at department stores have five to ten times as much space.

Aiiiieeee - a theropod! Aim for its head!

Aiiiieeee – a theropod! Aim for its head! Liem et al. (2001: fig. 8.17).

Of course, to get the full benefit you should also pick up a copy of the book. I see used copies going for under $40 in a lot of places online. Mine will have pride of place on my bookshelf until I enter the taphonomic lottery. And I’ll be raiding these PPTs for images from now until then, too.

Countercurrent gas exchange in fish gills - a very cool system.

Countercurrent gas exchange in fish gills – a very cool system. Liem et al. (2001: fig. 18.6).

So do the right thing, and go download this stuff, and use it. Be sure to credit Liem et al. (2001) for the images, and thank Willy Bemis for making them all available. It’s a huge gift to the field. Here’s that link again.

Liem et al 2001 PPTs - shark jaw and forelimb musculature

Dangit, if only there was a free online source for illustrations of shark anatomy… Liem et al (2001: fig. 10.12).

But wait – that’s not all! Starting on June 28, Dr. Bemis will be one of six faculty members from Cornell and the University of Queensland teaching a 4-week massively open online course (MOOC) on sharks. Freakin’ sharks, man!

“What did you do this summer? Hang out and play Nintendo?”

“Yep. Oh, and I also took a course on freakin’ sharks from some awesome shark experts. You?”

As the “massively open” part implies, the course is free, although you have the option of spending $49 to get a certificate of completion (assuming you finish satisfactorily). Go here to register or get more info.

Reference

  • Liem, K.F., Bemis, W.E., Walker, W.F., and Grande, L. 2001. Functional Anatomy of the Vertebrates. (3rd ed.). Thomson/Brooks Cole, Belmont, CA.

Clash of the Titans from above

Here’s the “Clash of the Titans” exhibit at the Sam Noble Oklahoma Museum of Natural History, featuring the reconstructed skeletons of the giant Oklahoma Apatosaurus – which I guess should now be called the giant Oklahoma apatosaurine until someone sorts out its phylogenetic position – and the darn-near-T. rex-sized Saurophaganax maximus, which may be Allosaurus maximus depending on who you’re reading.

Now, I love this exhibit in both concept and execution. But one thing that is more obvious in this view from the upper level balcony is that despite its impressive weaponry, a lone 3-to-5 ton Saurophaganax had an Arctic ice cap’s chance in the Anthropocene of taking down a healthy 30-meter, 40-50 ton apatosaur (which is to say, none). I like to imagine that in the photo above, the apatosaur is laughing at the pathetically tiny theropod and its delusions of grandeur.

Clash of the Titans from behind

In this shot from behind, you get a better look at the baby apatosaur standing under the big one, and it hints at a far more likely target for Saurophaganax and other large Morrison theropods: sauropods that were not fully-grown, which was almost all of them. I am hip to the fact that golden eagles kill deer, and some lions will attack elephants – as Cookie Monster says, “Sometime food, not anytime food” – but not only were smaller sauropods easier prey, they were far more numerous given the inevitable population structure of animals that started reproducing at a young age and made more eggs the bigger they got (as essentially all egg-laying animals do).

In fact, as discussed in our recent paper on dinosaur ontogeny (Hone et al. 2016), there may have been times when the number of fully-grown sauropods in a given population was zero, and the species was maintained by reproducing juveniles. The giant Oklahoma apatosaurine is a unique specimen today – by far the largest apatosaurine we have fossils of – but it may also have been an anomaly in its own time, the rare individual that made it through the survivorship gauntlet to something approaching full size.

Amazingly enough, there is evidence that even it was not fully mature, but that’s a discussion for another day. Parting shot:

Oklahoma Apatosaurus neck and head

Reference

What’s in Mike’s freezer?

February 26, 2016

What’s that in Mike’s freezer? Let’s take it out and have a look.

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Onto the table out in the garden …

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Unwrap another layer …

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Hang on! That looks like … It can’t be, can it?

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It is! It’s a buzzard!

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A buzzard with extremely serious claws!

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And a serious beak as well!

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Further bulletins down the line, when I get a chance to play with it properly.

(Title stolen shamelessly from John Hutchinson’s blog.)

ostrich peeing

cormorant peeing

alligator peeing

Stand by . . . grumpy old man routine compiling . . . 

So, someone at Sony decided that an Angry Birds movie would be a good idea, about three years after the Angry Birds “having a moment” moment was over. There’s a trailer for it now, and at the end of the trailer, a bird pees for like 17 seconds (which is about 1/7 of my personal record, but whatever).

And now I see these Poindexters all over the internet pushing their glasses up their noses and typing, “But everyone knows that birds don’t pee! They make uric acid instead! That’s the white stuff in ‘bird poop’. Dur-hur-hur-hurrr!” I am reasonably sure these are the same people who harped on the “inaccuracy” of the peeing Postosuchus in Walking With Dinosaurs two decades ago. (Honestly, how I didn’t get this written and posted in our first year of blogging is quite beyond my capacity.)

Congratulations, IFLScientists, on knowing One Fact about nature. Tragically for you, nature knows countless facts, and among them are that birds and crocodilians can pee. And since extant dinosaurs can and do pee, extinct ones probably could as well.

So, you know . . . try to show a little respect.

So, you know . . . try to show a little respect.

Now, it is true that crocs (mostly) and birds (always?) release more of their nitrogenous waste as uric acid than as urea. But their bodies produce both compounds. So does yours. We mammals are just shifted waaaay more heavily toward urea than uric acid, and extant archosaurs – and many (but not all) other reptiles to boot – are shifted waaaay more heavily toward uric acid than urea. Alligators also make a crapload of ammonia, but that’s a story for another time.

BUT, crucially, birds and crocs almost always release some clear, watery, urea-containing fluid when they dump the whitish uric acid, as shown in this helpful diagram that I stole from International Cockatiel Resource:

International Cockatiel Resource bird pee guide

If you’ve never seen this, you’re just not getting to the bird poop fast enough – the urine is drying up before you notice it. Pick up the pace!

Sometimes birds and crocs save up a large quantity of fluid, and then flush everything out of their cloacas and lower intestines in one shot, as shown in the photos dribbled through this post. Which has led to some erroneous reports that ostriches have urinary bladders. They don’t, they just back up lots of urine into their colons. Many birds recapture some water and minerals that way, and thereby concentrate their wastes and save water – basically using the colon as a sort of second-stage kidney (Skadhauge 1976).

Rhea peeing by Markus Buhler

Many thanks to Markus Bühler for permission to post his well-timed u-rhea photo.

[UPDATE the next day: To be perfectly clear, all that’s going on here is that the birds and crocs keep their cloacal sphincters closed. The kidneys keep on producing urine and uric acid, and with no way out (closed sphincter) and nowhere else to go (no bladder – although urinary bladders have evolved repeatedly in lizards), the pee backs up into the colon. So if you’re wondering if extinct dinosaurs needed some kind of special adaptation to be able to pee, the answer is no. Peeing is an inherent possibility, and in fact the default setting, for any reptile that can keep its cloaca shut.]

Aaaanyway, all those white urate solids tend to make bird pee more whitish than yellow, as shown in the photos. I have seen a photo of an ostrich making a good solid stream from cloaca to ground that was yellow, but that was years ago and frustratingly I haven’t been able to relocate it. Crocodilians seem to have no problem making a clear, yellowish pee-stream, as you can see in many hilarious YouTube videos of gators peeing on herpetologists and reporters, which I am putting at the bottom of this post so as not to break up the flow of the rant.

ostrich excreting

You can explore this “secret history” of archosaur pee by entering the appropriate search terms into Google Scholar, where you’ll find papers with titles like:

  • “Technique for the collection of clear urine from the Nile crocodile (Crocodylus niloticus)” (Myburgh et al. 2012)
  • “Movement of urine in the lower colon and cloaca of ostriches” (Duke et al. 1995)
  • “Plasma homeostasis and cloacal urine composition in Crocodylus porosus caught along a salinity gradient” (Grigg 1981)
  • “Cloacal absorption of urine in birds” (Skadhauge 1976)
  • “The cloacal storage of urine in the rooster” (Skadhauge 1968)

I’ve helpfully highlighted the operative term, to reinforce the main point of the post. Many of these papers are freely available – get the links from the References section below. A few are paywalled – really, Elsevier? $31.50 for a half-century-old paper on chicken pee? – but I’m saving them up, and I’ll be happy to lend a hand to other scholars who want to follow this stream of inquiry. If you’re really into the physiology of birds pooling pee in their poopers, the work of Erik Skadhauge will be a gold mine.

Now, to be fair, I seriously doubt that any bird has ever peed for 17 seconds. But the misinformation abroad on the net seems to be more about whether birds and other archosaurs can pee at all, rather than whether a normal amount of bird pee was exaggerated for comedic effect in the Angry Birds trailer.

ostrich excreting 3

In conclusion, birds and crocs can pee. Go tell the world.

And now, those gator peeing videos I promised:

UPDATE

Jan. 30, 2016: I just became aware that I had missed one of the best previous discussions of this topic, with one of the best videos, and the most relevant citations! The post is this one, by Brian Switek, which went up almost two years ago, the video is this excellent shot of an ostrich urinating and then defecating immediately after:

…and the citations are McCarville and Bishop (2002) – an SVP poster about a possible sauropod pee-scour, which is knew about but didn’t mention yet because I was saving it for a post of its own – and Fernandes et al. (2004) on some very convincing trace fossils of dinosaurs peeing on sand, from the Lower Cretaceous of Brazil. In addition to being cogent and well-illustrated, the Fernandes et al. paper has the lovely attribute of being freely available, here.

So, sorry, Brian, that I’d missed your post!

And for everyone else, stand by for another dinosaur pee post soon. And here’s one more video of an ostrich urinating (not pooping as the video title implies). The main event starts about 45 seconds in.

References

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