On Friday I gave you a fairly straightforward mystery object to identify – at least straightforward in that it wasn’t an odd section or a fragment of bone, instead it was a very characteristic skull:
As a result a good number of you correctly identified this, with zinjanthropus first past the post with a general identification, Neil with the correct genus and David Craven with the full species identification. So well done everyone, this specimen is indeed the skull of a Short-nosed Echidna Tachyglossus aculeatus (Shaw, 1792).
The tricky part of this identification was probably the strange resemblance that the skull has to that of a bird, which threw several people off the correct scent. After all, the Echidna has no teeth and it has a long ‘beak’ made of bone, much like a bird. The small eyes and the odd jaw closing mechanism of Echidnas make their skulls look superficially similar to some kind of short-billed Kiwi Apteryx sp. Indeed, Echidnas are unusual in a variety of ways, most notably in the laying of eggs, which is restricted in the mammals to the monotremes (Echidna and Platypus). Despite their egg-laying they are counted as mammals because they produce milk to feed their young (although not through nipples), they are hairy (in Echidnas some of that hair has formed quills similar to those of a porcupine) and they have three bones in each ear and one continuous bone that forms each side of the lower jaw (unlike birds and ‘reptiles’ that have a lower jaw composed of several bones). They can most easily be distinguished from birds by the lack of a ‘window’ in the bone in front of the eye and by the clear ‘ear-hole’ in the side of the skull.
So well done to everyone and I hope you’ll all be back for this week’s first anniversary mystery object – I have something very special in mind!
Nice one this week
Glad to hear it – can be hard to gauge what will be a good mystery object at times!
I feel silly now !
All my bird skulls you can see from one eye socket through to the other. Is that a good way of identifying bird skulls ?
Don’t feel silly – we all learn by getting things wrong sometimes! Anyway, you’re right about looking through bird’s eyes – mostly you can see straight through. Well spotted!
Well I’m pleased I got to monotreme without looking anything up. I don’t usually search to get the answer – do enough of that in the day job – just rely on what I’ve heard from you and the lunch club about taxonomy, what others say and wild guesses. But as I couldn’t remember the other montreme I did search, and in the process discovered Millie the Sydney Olympics IT mascot, which is an echidna. Very like Harty the Hertfordshire Hedgehog which you created when you were about eight, but not as well drawn.