On Friday I gave you this piece of skull to identify:

It was in the Horniman collections with no identification beyond a pencil note saying ‘Monkey?’, but that seemed to be a  bit of an odd suggestion, since primates have very rounded braincases – even the longer skulled ones like baboons. I think the person who made the tentative identification had got the section the wrong way round – thinking that the nuchal crest was a part of a brow-ridge or something – a mistake that Jake certainly didn’t make. They also missed what several of you spotted – the rugose (sort of wrinkly) structure that supported the olfactory epithelium (the inner back part of the nose where the receptors for smell are located).

What most of you did miss however, was the lack of fusion of the cranial sutures, which indicates that this was from a juvenile animal. As a result it is smaller and has far less well-developed muscle scars than an adult animal would have. A faint muscle scar can be seen converging on what looks like the beginnings of a sagittal crest (as pointed out by Manabu Sakamoto), so it seems reasonable to guess that the adult animal would have a reasonably well developed crest on the top of the braincase.

Eventually Neil dropped a couple of hints that showed he knew what it was and David Craven and KateKatV also suggested that they knew that it was part of the braincase of a juvenile Black bear Ursus americanus Pallas, 1780.

This particular specimen has an orange dot on it, that indicates it had been treated with methyl bromide insecticide when it entered the museum. This is typical of a large collection of comparative skeletal material that was donated in a couple of batches in the 1980s, from the collections of a couple of London colleges. Over the course of years of teaching some bits had become separated from specimens and by the time the collections came to us there were plenty of incomplete specimens and boxes of unassociated parts.

Once I had worked out that this was probably from a juvenile bear I was able to check on the bears in the collection and find this specimen from the same era:

It was incredibly satisfying to be able to reunite the top of this specimen’s skull, since it completes the specimen and it means that there is one less unidentified ‘bit’ in the collections. So now at least the poor dead bear cub has a more intact skull:

All that remains is to find the missing part of its zygomatic arch and some teeth – although I suspect that they were probably lost years before this specimen ever came to the museum. It’s all part of the fun of being a museum curator!