This week I have another skull for your identification delectation:
Any idea which species this specimen belongs to? If so, please don’t just blurt it out – drop some clues in the comments section below.
Have fun!
Friday mystery object #409
Zygoma
Adventures in natural history collections
Zygoma 
Ooh. I’m thinking a freshwater version of those things from Yeats’s Sailing to Byzantium.
Whoops. I meant Byzantium, not Sailing to Byzantium.
It shares a name with a Russian sturgeon, but this arctic whale is not related to it.
looks scary enough to be a Krampus. Maybe we should ask Risso if it is his.
Boo! I thought I was first! Paolo – Adam is your winner. I spent too long thinking it was a stupid narluga (of which there’s only one, ever, and it’s actually a belwhal). ☺️
I’m not quite desperate enough to go with narluga just yet – which is a thing, apparently.
But I that’s the closest so far amongst the “toothed whale skulls.”
Maybe it’s a belwhal (like the original narluga actually was)? The lack of top teeth is suspicious – narwhals only have a (left side) tusk (rarely, they can actually have 2 tusks), and no teeth.
Oh, she bewailed, the unicorn fell in the caviar!
We have moved away from the hybrid freaks. It’s a real species. Not a narluga, a belwhal – although that’s what I thought – or a wholphin (LOL). There may still only be one narluga in history (and that’s actually a belwhal).
OK. I’m going for the cross-breed/hybrid arctic whale. The dentition?
It’s a real species.
Could it be a bit like a Boris answer at PMQ
As in a cross EU blag ?
It would be interesting to know whether the upper teeth are absent or just lost
They naturally have no upper teeth, just the lower teeth.
This is one killer competition. (Couldn’t help making a pun attempt.)
I am assuming Goatlips has it right. Comment: isn’t it weird that such closely related species (the subfamily including this one) should have such very different dental arrangements? Having visible teeth only in the lower jaw isn’t a unique feature of this species: think Physeter. So maybe we should think of the species to which this skull belongs as being to the Orca … sort of what Physeter is too Livyatitan. But WHY?
Coming late to the senior party for the grampuses…