Carnivore Skull Challenge: the reveal

December 10, 2013

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.

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8 Responses to “Carnivore Skull Challenge: the reveal”

  1. Mike Taylor Says:

    I am delighted to say that I got one right!

  2. Neil Says:

    The example skull in the Mammalian Species entry for U. americanus is (to my eyes anyway) a dead ringer for the “roundhead” La Brea bear (pdf: Larivière 2001. That skull is labelled as a female so I suspect some of this variation in proportion, forehead shape and crest development is relatd to sexual dimorphism and probably ontogeny too. Do you know the age/sex of your specimen, looks like a pretty grumpy old dude?

    Interestingly this set (yearling, adult female, adult male) all seem to show the concave forehead, although part of that could be photo angle.

  3. Stevo Darkly Says:

    Wow. I did much horriblier* than I thought. At least I got the bear and the hyena right. I am super-delighted that I got one more right than Mike Taylor.

    I am especially surprised about I got the seal and the fossa wrong.

    And I had no idea that black bear skulls were so variable. I guess I lucked out that every bear skull I’ve seen happened to look like your test example.

    *I repeat: I majored in English in school.

  4. Matt Wedel Says:

    And I had no idea that black bear skulls were so variable. I guess I lucked out that every bear skull I’ve seen happened to look like your test example.

    Yeah, after I set this whole thing up precisely because bear skulls are so variable and they look like so many other things, and then almost everyone got the bear right off the bat–and some people only got the bear, I was like, “What the hell?” But, hey, there’s no reason to run an experiment if you’re not open to the prospect of being surprised by the results.

  5. Dean Says:

    :) It seems my vertebrate osteology class will pay off. The Fossa skull threw me, it looks like it came from a much larger animal!

  6. AnJaCo Says:

    My old Mammology TA wishes to remain anonymous.

  7. hi Says:

    0MG! I got ALL of them correct without guessing a single answer! I can’t believe it! I guess my classes really helped.

  8. Mike Taylor Says:

    Congratulations!


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