Here’s one of my most prized possessions: a cannon bone from a giraffe. I got it last fall from Necromance, a cool natural history store in LA. Originally they had a matched pair on display in the front window. Jessie Atterholt got one of them last summer, and I got the other a few months later.

The cannon bones of hoofed mammals consist of fused metacarpals (in the forelimbs) or metatarsals (in the hindlimbs). In this case, the giraffe cannon bone in the top photo is the one from the right forelimb, consisting of the fused 3rd and 4th metacarpals, which correspond to the bones in the human hand leading to the middle and ring fingers. Only my third metacarpal is traced in the top photo. For maximum homology goodness I should have traced MC4, too, but I’m lazy.

I didn’t know that this was a right forelimb cannon bone when I got it. In fact, I only figured that out this afternoon, thanks to the figures and text descriptions in Rios et al. (2016), which I got free through Palaeontologia Electronica (you can too). The weirdly large and perfectly circular holes at the ends of my cannon bone were clearly drilled out by somone, I guess maybe for mounting purposes? At first I thought it might have been to help the marrow cook out of the shaft of the bone during simmering and degreasing, but none of the drilled holes intersect the main marrow cavity, they’re just in the sponge of trabecular bone at the ends of the element.

This post is a sequel to one from last year, “Brachiosaurus and human metacarpals compared“, which featured metacarpal 3 from BYU 4744, the partial skeleton of Brachiosaurus from Potter Creek, Colorado. I know what everyone’s thinking: can we make these two high-browsing giants throw hands?

Yes, yes we can. The giraffe cannon bone is 75.5cm long, and the brachiosaur metacarpal is 57cm long, or 75.5% the length of the giraffe element. I scaled the two bones correctly in the above image. My hands aren’t the same size because they’re at different distances from the camera, illustrating the age-old dictum that scale bars are not to be trusted.

The Potter Creek brachiosaur is one of the largest in the world–here’s me with a cast of its humerus–but ‘my’ giraffe is not. World-record giraffes are about 19 feet tall (5.8m), and doing some quick-and-dirty cross-scaling using the skeleton photo above suggests that the metacarpal cannon bone in a world-record giraffe should be pushing 90cm. So the giraffe my cannon bone is from was probably between 15.5 and 16 feet tall (4.7-4.9m), which is still nothing to sniff at.

I don’t know how this bone came to be at Necromance. I assume from an estate sale or something. I only visited for the first time last year, and at that time they had three real bones from giraffes out in the showroom: the two cannon bones and a cervical vertebra. They might have put out more stuff since–it’s been about six months since I’ve been there–but all of the giraffe bones they had at that point have been snapped up by WesternU anatomists. Jessie and I got the cannon bones, and Thierra Nalley got the cervical vertebra, which is fair since she works on the evolution of necks (mostly in primates–see her Google Scholar page here). I don’t know if there are any photos of Thierra’s cervical online, but Jessie did an Instagram post on her cannon bone, which is nearly as long as her whole damn leg.

There will be more anatomy coming along soon, and probably some noodling about sauropods. Stay tuned!

Reference

Ríos M, Danowitz M, Solounias N. 2016. First comprehensive morphological analysis on the metapodials of Giraffidae. Palaeontologia Electronica 19(3):1–39.

 

 

Click to embiggen. Trust me.

Last year about this time I wrote:

Here’s a stupid thing: roughly 2-3 times a year I go to the field or to a museum and get hundreds of SV-POW!-able photos. Then I get back to the world and catch up on all of the work that piled up while I was away. And by the time I’m done with that, whatever motivating spark I had – to get some of those photos posted and talk about the exciting things I figured out – has dissipated.

The museum I was thinking about more than any other when I wrote that is the Museum of Osteology in Oklahoma City. I don’t get there every year, but I stop in as often as possible, and I make it more years than not. And yet, looking back through the archives I see that almost all of my posts about the Museum of Osteology came in a brief flurry five years ago. Shameful!

This summer I was out in the Oklahoma panhandle for fieldwork with Anne Weil, then I had a very quick day in the collections at the OMNH in Norman, then I had to drop my son London with relatives (he stayed for an extra week) and hop a plane home. In between the kid hand-off and the drop-dead get-to-the-airport time I had exactly one spare hour, so of course I hit the museum.

IMG_0571

UPDATE: for the curious, here’s the signage for the hanging humpback whale skeleton.

The Museum of Osteology is easily one of my favorite natural history museums in the world. Like all my favorite museums, it just packed to the gills with actual natural history objects. The signage is tasteful, informative, and discreet, and there is a blessed absence of blaring videos, rotating 3D whatsits, and interactive geegaws to ruin the experience.* You can walk all the way around the big mounted skeletons with no glass in the way. The staff are friendly and helpful, and as you can see from the photos, they even provide comfortable benches for people who wish to sit and ponder the endless forms most beautiful.

That, folks, is a damn fine museum.

* To be clear, I don’t think all videos and interactive displays are evil. But they need to enhance the experience of natural history, not be a substitute for it, and that’s a distinction that seems lost on many exhibit designers.

I was taken by this conjunction of two water-adapted artiodactyls.

Here’s the hippo by itself if you want the whole skeleton.

And a rhino to round out the big African megafauna. I showed the giraffe in this old post.

Even familiar animals that you may think you know front-to-back are often presented in new and interesting ways. I adore this horse skull, which has the maxilla and mandible dissected to show the very tall, ever-growing teeth, which erupt continuously through the horse’s life until the crowns are entirely worn away.

The textures on this giraffe skull are pretty mind-blowing.

I strongly recommend zooming in and tracing out some blood vessel pathways, especially over the orbit, at the bases of the ossicones, and in the temporal fossa (below the ossicones and behind the orbit).

Bottom line, if you are interested in the natural world at all, you owe it to yourself to visit this museum. And you’ll want to go as heavy in the wallet as you can manage, because the gift shop is ridiculous and can easily eat 30-45 minutes and all your disposable income. Take it from a survivor.

Frog RLN ventral view - Ecker 1889 plate 1 fig 115 - RLN highlighted

Just posting a few images from my impending talk at SVPCA this Thursday.

I’ve written about the recurrent laryngeal nerve before, in Wedel (2012) and in this post. It’s present in all tetrapods, from frogs and salamanders on up. The frog RLN is shown in ventral view above, and in lateral view below, both from Ecker (1889:plate 1, figures 114 and 115). I’ve highlighted the RLN in red in both. Perhaps not a monument of inefficiency, but still recurrent, and therefore dumb.

Frog RLN lateral view - Ecker 1889 plate 1 fig 114 - RLN highlighted

And in a giraffe – RLN in blue, nerve path to hindfoot phalanges in red. Hollow circles are nerve cell bodies, solid lines are axons.

Giraffe skeleton silhouette 1000 with nerves

And in the elasmosaur Hydrotherosaurus, same color scheme plus the nerve path to the tail in purple, base image from Welles (1943).

Hydrotherosaurus nerve pathways 4 - RLN pathway

That’s all for now!

References

I imagine that by now, everyone who reads this blog is familiar with Mark Witton’s painting of a giant azhdarchid pterosaur alongside a big giraffe. Here it is, for those who haven’t seen it:

Arambourgiania vs giraffe vs the Disacknowledgement redux Witton ver 2 low res

(This is the fifth and most recent version that Mark has created, taken from 9 things you may not know about giant azhdarchid pterosaurs.)

It’s one of those images that really kicks you in the brain the first time you see it. The idea that an animal the size of a giraffe could fly under its own power seems ludicrous — yet that’s what the evidence tells us.

But wait — what do we mean by “an animal the size of a giraffe”? Yes, the pterosaur in this image is the same height as the giraffe, but how does its weight compare?

Mark says “The giraffe is a big bull Masai individual, standing a healthy 5.6 m tall, close to the maximum known Masai giraffe height.” He doesn’t give a mass, but Wikipedia, citing Owen-Smith (1988), says “Fully grown giraffes stand 5–6 m (16–20 ft) tall, with males taller than females. The average weight is 1,192 kg (2,628 lb) for an adult male and 828 kg (1,825 lb) for an adult female with maximum weights of 1,930 kg (4,250 lb) and 1,180 kg (2,600 lb) having been recorded for males and females, respectively.” So it seems reasonable to use a mass intermediate between those of an average and maximum-sized male, (1192+1930)/2 = 1561 kg.

So much for the giraffe. What does the azhdarchid weigh? The literature is studded with figures that vary wildly, from the 544 kg that Henderson (2010) found for Quetzalcoatlus, right down to the widely cited 70 kg that Chatterjee and Templin (2004) found for the same individual — and even the astonishing 50 kg that seems to be favoured by Unwin (2005:192). In the middle is the 259 kg of Witton (2008).

It occurred to me that I could visualise these mass estimates by shrinking the giraffe in Mark’s image down to the various proposed masses, and seeing how credible it looks to imagine these reduced-sized giraffes weighting the same as the azhdarchid. The maths is simple. For each proposed azhdarchid mass, we figure out what it is as a proportion of the giraffe’s 1561 kg; then the cube root of that mass proportion gives us the linear proportion.

  • 544 kg = 0.389 giraffe masses = 0.704 giraffe lengths
  • 259 kg = 0.166 giraffe masses = 0.549 giraffe lengths
  • 70 kg =0.0448 giraffe masses = 0.355 giraffe lengths

Let’s see how that looks.

Arambourgiania vs giraffe vs the Disacknowledgement redux Witton ver 2 low res

On the left, we have Mark’s artwork, with the giraffe massing 1561 kg. On the right, we have three smaller (isometrically scaled) giraffes of masses corresponding to giant azhdarchid mass estimates in the literature. If Don Henderson (2010) is right, then the pterosaur weighs the same as the 544 kg giraffe, which to me looks pretty feasible if it’s very pneumatic. If Witton (2008) is right, then it weighs the same as the 259 kg giraffe, which I find hard to swallow. And if Chatterjee and Templin (2004) are right, then the giant pterosaur weighs the same as the teeny tiny 70 kg giraffe, which I find frankly ludicrous. (For that matter, 70 kg is in the same size-class as Georgia, the human scale-bar: the idea that she and the pterosaur weigh the same is just silly.)

What is the value of such eyeball comparisons? I’m not sure, beyond a basic reality check. Running this exercise has certainly made me sceptical about even the 250 kg mass range which now seems to be fairly widely accepted among pterosaur workers. Remember, if that mass is correct then the pterosaur and the 259 kg giraffe in the picture above weight the same. Can you buy that?

Or can we find extant analogues? Are there birds and mammals with the same mass that are in the same size relation as these images show?

References

  • Chatterjee, Sankar, and R. J. Templin. 2004. Posture, locomotion, and paleoecology of pterosaurs. Geological Society of America, Special Paper 376. 68 pages.
  • Henderson, Donald M. 2010. Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology 30(3):768-785.
  • Witton, Mark P. 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana 28:143-159.

Crocodiles vs. elephants

November 18, 2014

I’ve been reading The Guinness Book of Animal Facts and Feats (Wood 1982) again. Here’s what he says on pages 98-99 about the strength of crocodiles, and what happens when they bite off more than they can chew.

The strength of the crocodile is quite appalling. Deraniyalga (1939) mentions a crocodile in N. Australia which seized and dragged into the river a magnificent 1 tonne Suffolk stallion which had recently been imported from England, despite the fact that this breed of horse can exert a pull of more than 2 tonnes, and there is at least one record of a full-grown black rhinoceros losing a tug-of-war with a big crocodile. Sometimes, however, even crocodiles over-estimate their strength. One day in the 1860s a hunter named Lesley was a witness when a saurian seized the hind-leg of a large bull African elephant while it was bathing in a river in Natal. The crocodile was promptly dragged up the bank by the enraged tusker and then squashed flat by one of its companions who had hurried to the rescue. The victorious elephant then picked up the bloody carcase with its trunk and lodged it in the fork of a nearby tree (Stokes, 1953). Oswell (1894) says he twice found the skeletons of crocodiles 15 ft 4.6 m up in trees by the river’s bank where they had been thrown by angry elephants. On another occasion a surprised crocodile suddenly found itself dangling 15 ft 4.6 m in mid-air when it foolishly seized a drinking giraffe by the head.

The idea of elephants lodging crocodile corpses up in trees seems too bizarre to be true, but seeing it independently attested by two witnesses makes me more ready to accept it. There’s plenty of Internet chatter about this happening, but I’ve not been able to find photos — or better yet, video — proving that it happens.

References

  • Deraniyalga, P. 1939. The tetrapod reptiles of Ceylon, vol. 1: Testudinates and crocodilians. Colombo Nat. Mus., Ceylon.
  • Oswell, W. Cotton. 1894. South Africa fifty years ago. Badminton Library of Sports and Pastimes (Big Game Shooting), London.
  • Stokes, C. W. 1953. Sanctuary. Cape Town.
  • Wood, Gerald L. 1982. The Guinness Book of Animals Facts & Feats (3rd edition). Guinness Superlatives Ltd., Enfield, Middlesex. 252 pp.

Just a quick post to link to all six (so far) installments of the “necks lie” series. I need this because I want to cite all the “necks lie” posts in a paper that I’ll shortly submit, and it seems better to cite a single page than four of them.

I’ll update this post as and when we write more about lying necks.

Also:

What a world we live in.

X-ray of the neck of a seal, from Irish Seal Sanctuary. Note that the vertebral column becomes much more vertical than the fleshy envelope suggests.

X-ray of the neck of a seal, from Irish Seal Sanctuary. Note that the vertebral column becomes much more vertical than the fleshy envelope suggests.

Folks,

You may know that the inaugral TetZooCon is set to take place next Saturday (12 July) at the London Wetland Centre. It’s an informal convention that’s condensed around occasional SV-POW!sketeer Darren Naish’s absurdly informative blog Tetrapod Zoology, and features a day of talks, a palaeoart workshop and a quiz. At £40 for the day, it’s a bit of a bargain.

Among the speakers is my own good self, and I will be talking about why giraffes are rubbish.

Taylor and Wedel 2013a: Figure 3. Necks of long-necked sauropods, to scale. Diplodocus, modified from elements in Hatcher (1901, plate 3), represents a “typical” long-necked sauropod, familiar from many mounted skeletons in museums. Puertasaurus, Sauroposeidon, Mamenchisaurus and Supersaurus modified from Scott Hartman’s reconstructions of Futalognkosaurus, Cedarosaurus, Mamenchisaurus and Supersaurus respectively. Alternating pink and blue bars are one meter in width. Inset shows Fig. 1 to the same scale.

Taylor and Wedel 2013a: Figure 3. Necks of long-necked sauropods, to scale. Diplodocus, modified from elements in Hatcher (1901, plate 3), represents a “typical” long-necked sauropod, familiar from many mounted skeletons in museums. Puertasaurus, Sauroposeidon, Mamenchisaurus and Supersaurus modified from Scott Hartman’s reconstructions of Futalognkosaurus, Cedarosaurus, Mamenchisaurus and Supersaurus respectively. Alternating pink and blue bars are one meter in width. Inset shows Fig. 1 to the same scale.

If that sounds like your idea of a good time, then you need to move fast! Booking closes at 4pm this evening. Better get on it now!

 

Order up!

Sauroposeidon OMNH 53062 articulated right lateral composite with giraffe

Sauroposeidon is stitched together from orthographic views of the 3D photogrammetric models rendered in MeshLab. Greyed out bits of the vertebrae are actually missing–I used C8 to patch C7, C7 to patch C6, and so on forward. The cervical ribs as reconstructed here were all recovered and they are in collections, but they’re in several jackets and boxes and therefore not easily photographed.

The meter bars are both one meter as advertised. The giraffe neck is FMNH 34426 (from this post), which is actually 1.7 meters long, but I scaled it up to 2.4 meters to match that of the tallest known giraffe. I think it’s cool that a world-record giraffe neck is roughly as long as two vertebrae from the middle of the neck of Sauroposeidon.

There are loads of little morphological details in the Sauroposeidon vertebrae that are clearer now than they were in our old photographs, but those will be stories for other posts.

Giraffe neck FMNH 34426 articulatedThe cervical series of Giraffa camelopardalis angolensis FMNH 34426, articulated by Mike and me and photographed by Mike back in the summer of 2005, cropped and composited by me recently, not previously posted because there’s just too much cool stuff, man. But we’re working on it.

By the way, if you want the details on this critter:

FMNH 34426 specimen tag

UPDATE April 23, 2014: What a maroon–I completely forgot to report the size of this thing! When we articulated all the centra and measured them (without cartilage, obviously), we got a length of 171 cm. When we measured the centra individually, leaving off the anterior condyles, we got a length of 164 cm. I think the discrepancy can be explained by the relative shallowness of the posterior cotyles of the vertebrae–as you can see in the big image above, the condyles do not nest completely within the cotyles, so each one does contribute a little bit to the length of the neck.

The measurements of each vertebra, as recorded by Mike in my notebook in the FMNH mammalogy collections in 2005, are here:

Giraffa FMNH 34426 cervical and dorsal measurements

Just for completeness, I should note that in our neck cartilage paper (Taylor and Wedel 2013b), we found that cartilage added considerably to the length of the articulated neck in many amniotes. Based on the intervertebral spacing in horses, 1-2 cm of cartilage between these giraffe vertebrae doesn’t seem unreasonable, which would bring the length of the neck to perhaps 1.8 meters. Amazingly, this is only 75% of the longest giraffe necks on record, which are up to 2.4 meters (Toon and Toon 2003).

References

supersaurus-vs-giraffe

At the top: our old friend BYU 9024 — the cervical vertebra that’s part of the Supersaurus vivianae holotype. At the bottom, C2 (the longest cervical) of Giraffa camelopardalis angolensis FMNH 34426.

The Supersaurus vertebra is 138 cm long. We don’t know which cervical it is, but there’s no reason to think it’s the longest. The giraffe vertebra is 31 cm long. Not only is the Supersaurus vertebra four times as long as that of the giraffe, it’s one of more than twice as many cervicals as the giraffe has.

Did we cheat by using an unusually small giraffe? Not really. When we articulated all seven cervicals as best we could, the sequence measured 171 cm, which is a fairly healthy 71% of the 2.4 m neck of the world-record giraffe. It’s not a monster, but it’s a decent-sized adult.

Bottom line, giraffes are just lame.