Last week I gave you this mystery skull to have a go at identifying:

I didn’t think it would pose as much of a challenge as it did, but as I hinted when setting the question, this specimen is on the chunky side and I think the robustness threw some of you off the scent.

Allen Hazen offered a suite of great observations and considerations (which is well worth a read), but katedmonson and Adam Yates were on the right track from the get-go in the comments and the Twitterati twigged pretty quickly. This skull is from a Raccoon Procyon lotor (Linnaeus, 1758).

Most Raccoon skulls I’ve seen have been smaller and a lot more gracile than this chunkster, so when I first spotted this specimen it took me a moment to recognise the species. In particular, this specimen has very well-developed muscle scars around the zygomatic arches (cheekbones) and sagittal crest (the ridge along the midline of the braincase) compared to the younger specimens that I tend to see, such as this one from my handling collection:

This robustness in the mystery object changes the profile of the skull to some extent, making it more rounded on top and wider across the cheeks. The canines are also larger and the various suture lines are more fully fused, making it seem to be from a more formidable animal than a Raccoon – like a Wolverine or Honey-badger (both of which were suggested on Twitter).

This sort of cranial variation within a species is always interesting to me, since it reflects the biomechanical forces acting on the bone during the animal’s life. It will be influenced by the sex and age of the animal as well, so it illustrates why it’s important for collections to hold several examples of any species, with different sexes and developmental stages represented.

Thanks to everyone for their comments on this – it’s always interesting to get an insight into your thought processes!