Bare bear bone: beautiful

December 17, 2013

Ursus americanus - canines

Yes, it’s bear skulls on the brain lately. I have nothing scientific to say here, I was just going through old files and found myself struck by the beautiful form and texture of the bones. The photos are all close-ups of this skull of an American black bear, Ursus americanus.

Ursus americanus - smile

Ursus americanus - nasal-frontal sutures

Part of the forehead, where the nasal bones (bottom center) and maxillae (either side) meet the frontals (top).

Ursus americanus - temporal bone

The left temporal bone in posterodorsal view; anterior is to the left. The open web of bone in the middle of the photo is one of the pneumatic sinuses inside the temporal bone. The round hole just above the web enclosed a blood vessel in life. The half-tube on the right is the bottom half of external auditory meatus, or bony ear-hole (where you stick the Q-tip when you clean your ears, if you’re a reckless, safety-warning-diregarding outlaw). All of this got exposed when a bullet or shotgun slug took the back quarter of this bear’s head off, as described here.

Personally I’d be happier if the skull was still in the bear and the bear was still doing its bearish business, but as long as it’s dead anyway, we might as well learn what we can from the remains (my universal policy on dead animals). And also just stop now and then to appreciate their natural intricacy and beauty.

Many thanks to everyone who played pin-the-skull-on-the-carnivore. The answers are down at the bottom of this post, so if you’ve just arrived here and want to take the challenge, go here before you scroll down.

To fill up some space, let me point out how crazy variable the skulls of black bears, Ursus americanus, are.

My bear skull - left lateral reversed

Here’s the one I helped dig up, missing the occipital region. Note the double inflection in the dorsal outline that separates the forehead from both the snout and top of the head, and the way the nasal bones stick out at a very different angle from the maxilla.

Page Museum black bear skull

Here’s the skull of a black bear from the La Brea tar pits, in the Page Museum in L.A. I don’t know if this one was female or juvenile or what, but the dorsal margin of the skull is one mostly-smooth curve from occiput almost to incisors, with the nasals scarcely deviating at all. Lest you think these differences were caused by evolutionary change rather than intraspecific variation, similar “roundhead” bear skulls from modern times are here and here and near the bottom of this page.

It’s this variability that first got me thinking about doing the Carnivore Skull Challenge. I saw a couple of photos of skulls of wolverines, and except for having carnassial cheek teeth instead of flatter premolars and molars, the wolverine skulls look like they could fit right into the span of black bear skull variability (in shape; obviously they’re not nearly as big). Then I saw a hyena skull and thought that it wasn’t that far off from a wolverine either. A little more searching for plausible distractors and I was all set.

Here are the answers, by the way:

Carnivore skull challenge - answersIt’s kind of ironic, then, that the first two people to venture identifications picked out the black bear right away. In the very first comment, Dean got it almost all right except for swapping the seal and the fossa. Dean was also the first to get all of the skulls correctly identified, albeit on his second pass. Markus Bühler (of Cthulhu-sculpting fame) was the first to get them all the first time. Tom Nutter, our own Darren Naish, and microecos Neil also aced the test, although in light of the Page Museum bear skull shown above, I was amused to see Darren’s “D: Bear. Because forehead.” I guess it’s one of those presence-of-forehead-means-bear, absence-of-forehead-does-not-rule-out-bear things that logicians are always going on about.

I was really happy to see people getting the wolverine and hyena mixed up, because they really do look strikingly similar to me. It’s almost like hyena + bear = wolverine.

Brian Engh asked on Facebook when I was going to do one for sauropods. Patience, good sir! It’s on my to-do list.

Finally, speaking of bear skulls, you can get a sweet tiny bronze one with a hinged jaw as part of this already successful Kickstarter, or from Fireandbone.com once the Kickstarter ends.

Something very different, and very unexpected, tomorrow.

Carnivore skull challenge

In this image I have assembled photos of skulls (or casts of skulls) of six extant carnivores. I exclusively used photos from the Skulls Unlimited website because they had all the taxa I wanted, lit about the same and photographed from similar angles. The omission of scale indicators is deliberate.

Your mission, should you choose to accept it, is to match these skulls with the animals they came from. Here are their currently-understood hierarchical relationships, scientific names, and common names (aside: I know this is ugly, is there a way to make nested tables in WordPress?).

Carnivora

- – Herpestoidea

- – – – Eupleridae

- – – – – – Fossa, Cryptoprocta ferox

- – – – Hyaenidae

- – – – – – Brown hyena, Hyaena brunnea

- – Arctoidea

- – – – Ursoidea

- – – – – – American black bear, Ursus americanus

- – – – Musteloidea

- – – – – – European badger, Meles meles

- – – – – – Wolverine, Gulo gulo

- – – – Pinnipedia

- – – – – – Mediterranean monk seal,  Monachus monachus

If you accept the challenge, leave your guesses as comments below, but only if you’ve played fair–no checking websites, references, or your own skull collection! Don’t worry about being wrong, I freely admit that I would have flunked this bigtime if anyone else had inflicted it on me. I decided to set up this challenge after I noticed the striking similarity between two of these critters in particular; I’ll tell you which two when I post the reveal in a day or two.

Dödös need röck döts

November 12, 2013

Dodo skull drawing MJW 2013

It’s a strange time of year for me. Teaching and SVP are both behind me, my tenure dossier is in (I’ll find out how that goes next April, probably), and for the first time in a while, I’m not shepherding any pressing manuscripts through the valley of potential rejection. Urgency has dissipated. Flights of fancy are very in right now.

Take this post. I was supposed to be writing about intervertebral cartilage thickness in sauropods, but I got distracted and drew this instead. I am going through one of my periodic bouts of fascination with dodos, inspired by the awesome poster by Biedlingmaier et al. at SVP. So here’s an attempt. It’s based on this photo from Arkive:

Arkive Dodo-skull

with some details filled in from this plate from Strickland and Melville (1848):

Strickland and Melville dodo skull

and, to be honest, a very generous helping of artistic license. I don’t know from bird skulls so I may have the basioccipital wired to the nasals or some other godawful assault on sanity. I did it for fun, not for science.

If you want dodo science, I have mixed great news. Crappily–and futilely–enough, Owen’s descriptive papers on the dodo are paywalled at Transactions of the Zoological Society of London. (Seriously, guys? After 140 years you still haven’t made your nut off those papers?) BUT you can get them for free from a couple of other places–see Sarah Werning’s comment below. And happily Strickland and Melville (1848) is available for free from the Internet Archive, and in a host of formats. I am sorely tempted to have a hardcopy printed through Lulu. For more on the dodo side of the Aves 3D project underway at the Claessens lab, of which the Biedlingmaier et al. poster is early fruit, check out the news stories here, here, and here, and keep your fingers firmly crossed for the coming year. I can say no more for now.

If, like me, you are just a dodo fanperson, these videos with Adam Savage make interesting viewing: originalsequel.

Röck döts inspired by a few hours of stippling, and copied and pasted, appropriately, from False Machine.

References

moo-2011-flamingo-neck

But not “funny ha-ha”. More like, “funny how that neck is clearly impossible.” I mean, really.

This is another shot from the Museum of Osteology in Oklahoma City. A few hundred more posts like this and I’ll be done.

For more flamingo-related weirdness, check out Casey Holliday’s work (with Ryan Ridgely, Amy Balanoff, and Larry Witmer) on the wacky blood vessels in flamingo heads. Unfortunately, Holliday et al. found no evidence of the antigravity generators that are obviously present in flamingoes somewhere. So there’s more work to be done here.

Kinda makes me sad, to ponder all of the sweet soft-tissue adaptations that extinct organisms must have had, that we will probably never know (enough) about. At least we have freaks like this around to remind us.

Anyone who’s found the SV-POW! Tutorials useful will also like the excellent, detailed osteology posts on Tom Carr’s newish blog Tyrannosauroidea Central. Highly recommended — especially for those, like me, who have a lot to learn about skulls.

xx

Composite skull of a subadult Albertosaurus libratus in right lateral view with the major openings and struts labeled. From the first of Carr’s blog entries, linked below.

Here are the osteology posts so far:

If your museum doesn't look like this, you should reconsider your existence.

If your museum doesn’t look like this, you should reconsider your existence.

We’re just back from SVPCA 2013 in Edinburgh. The first part of the meeting was held at the Royal Society of Edinburgh, but on Friday we moved to the National Museums Scotland. Which is awesome. And free to the public. The design process for the museum seems to have been, “Okay, let’s get one of, oh, every interesting thing in the world, and put it right here.” We have tons more photos of amazing things from the museum, and maybe we’ll get around to posting them sooner or later, but today I have other things to do.

This pathetic, racially senescent freak is destined for evolution's dustbin.

This pathetic, racially senescent freak is destined for evolution’s dustbin. And he knows it.

Like make fun of Mike. And talk about vomiting dinosaurs.

Dude, this party totally ro-BLAAAUUGGH!!

Dude, this party totally ro-BLAAAUUGGH!!

This groovy stuffed fulmar, Fulmarus glacialis, is shown in the act of puking, which it does to dissuade predators. And probably everyone else. I am reliably informed by Darren that this is unrealistic fulmar vomit, and that the real thing is  more of a thin stream, like the world’s nastiest water gun, which can be directed with considerable accuracy. Note to self: don’t piss off the fulmars.

Vomiting sauropod by Wedel and NichollsLast year cemented “drawing goofy sauropods down at the pub” as a regular SVPCA Thing. So one night I was out with Mike and Darren and paleoartist Bob Nicholls, who is famous around these parts as the creator of the Greatest. Paleoart. Ever. I did a goofy sketch in my notebook illustrating the “defensive vomit” hypothesis, which Brian Engh and I cooked up during this alligator dissection. More on that another time, maybe. Anyway, after bashing out a fairly pathetic sauropod-puking-on-theropod scene, I passed the notebook to Bob and said, “Make this not suck”. Which he did. (Seriously, if you could see my original scrawl, you’d be the one throwing up.)

So now I have an original Bob Nicholls sketch–heck, the world’s first Wedel-Nicholls artist collaboration!–in my notebook, of one of evolution’s most majestic successes responding appropriately to a vulgar, overstudied theropod. Bob drew it right in front of me and I got to drink good beer while I watched him work.

And that, more or less, is why I attend SVPCA.

Giant Irish Mike - cut out

I couldn’t sign off without giving you another version of Giant Irish Mike, with the background cropped out so he can be dropped right into posters, slide shows, and other works of science and art. I really, really hope that he turns up in conference talks and other presentations in the months and years to come. If so, send us a photo documenting his miraculous apparition and we’ll show it to the world.

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