Last week I gave you this guest mystery object from the comparative anatomy collection of the Harry Brookes Allen Museum of Anatomy and Pathology at the University of Melbourne, courtesy of Rohan Long:

This is one of those specimens that it can take a while to get your head around, as most of the key features are entirely missing. From the top, the skull almost looks mammalian. Perhaps a little like a large rodent missing part of its zygomatic arches:

Even from the side there are some similarities, although it looks a bit more like a turtle:

If you look closely at the underside of the skull, you’ll notice that it has a single occipital condyle, which is something you see in reptiles and birds, but that view of the underside also becomes clear that the front section of the mystery object doesn’t taper to create a bill, like you’d see in a turtle:

In fact, a bill is the most diagnostic feature that’s missing, and that’s because it’s fallen off.

Those cervical vertebrae are quite distinctively avian – and from a long-necked avian at that. Once you realise that this is the braincase of a fairly large long-necked bird, the next task thing is to look at birds with a bulbous and cleft region on the head, just at the base of the bill (most bird skulls taper down to the bill).

For me that indicates one species above all others – the Mute Swan Cygnus olor (Gmelin, JF, 1789).

I’d like to offer a hearty ‘bravo’ to Adam Yates, who was the first to comment and correctly identify this with a great cryptic clue:

It is an anseriform for sure the large oval basipterygoid articulations are a give away. With that profile, i’d lose my voice while trying to say the name of a certain Western Australian River.

Adam Yates: January 20, 2023 at 8:45 am Edit

This was backed up the ever-knowledgable Wouter van Gestel who runs SkullSite, which is the single most useful online resource I know of for bird skull identifications. Speaking of useful online resources, Rohan has been working on a project to make the collections of the Harry Brookes Allen Museum of Anatomy and Pathology available online – so be sure to check it out!