On Friday I gave you this skull to identify:
I deliberately didn’t provide a scale bar, partly because I wanted to demonstrate how important it can be to have a sense of scale when identifying a specimen and partly to make the specimen a bit more challenging to identify.
Nonetheless, most of you got a correct identification, with some very good subtle hints being used to communicate that fact. So well done to Jack Ashby, David Craven, CopilasDenis, Dave Godfrey and Manabu Sakomoto, who all hinted or explicitly stated that this was the skull of a Spotted Hyaena Crocuta crocuta (Erxleben, 1777).
I know it’s not a bear now but it still looks like a bear to me because of the four cheek teeth and the hook on the jaw and the bits round the eyes and because it looks like a bit of a scary animal. What are the bits where you can tell it isn’t really a bear? I can’t tell.
Well, to help point out the differences here’s a Black Bear skull:
The most obvious major difference between the two skulls is in the shape and size of the cheek teeth. Hyaenas have huge, robust teeth when compared to the Bear, which is an adaptation to cracking bone. You may also notice that the Hyaena has much more blade-like molar teeth than the Bear, which has quite flat molars. This reflects the much more carnivorous diet of the Hyaena in comparison with the omnivorous diet of bears. Blade-like teeth are great for chopping a leg to bits, but they’re not much use when it comes to mashing up roots, berries and worms – for that you need grinding teeth.
This difference in molar shape is actually quite important in the Carnivore family tree, since it’s one of the features that helps distinguish the major split between the cat-like and dog-like forms. The cat-like forms tend to have the more highly specialised blade-like carnassial teeth, while the dog-like forms have more generalist molars that include grinding surfaces. That said, I would be no more keen on a dog-like Bear gnawing on my leg than the cat-like Hyaena.