On Friday I gave you this mystery object from the collections at the Horniman Museum to identify:
The bone is interesting because it was badly broken when the animal was alive. As Jake pointed out, the bone has healed without the attentions of a vet, so it hasn’t healed straight and there’s a lot of excess bone growth. This makes it harder to work out what the bone originally looked like.
Minioncat recognised that this is the humerus of a juvenile animal and although there were several species suggested on the basis of size, none seemed to quite fit.
Lena made a really helpful observation about the presence of a supracondylar foramen – which is the hole that can be clearly seen on the side of the bone in the top image, near the articulation on the right hand-side of the picture.
This foramen is something seen in some of the carnivores, like cats and mustelids, but the bone itself doesn’t really match any of the cat or mustelid bones that I compared it to.
When I first found this bone I though that it belonged to a tree-climbing (or arboreal) carnivore, because the head of the humerus would allow for a considerable range of movement (plus broken bones are common in arboreal animals). The only thing I could really think of that was likely was a small species of bear, since cat humeri are quite different from this.
However, on Twitter Raymond Vagell made the inspired suggestion that it could be the humerus of a Fossa Cryptoprocta ferox Bennett, 1833 – something that I never even considered.
I don’t have any Fossa postcrania for comparison and I can’t even find a good image of a Fossa humerus online, so it’s hard to check. There is a Fossa skeleton image on the Museum Victoria website, which shows that the humerus is pretty similar, but alas it’s a clear enough image to be more sure.
Once I started thinking about less commonly occurring carnivores I broadened my search and came across a paper with a comparative drawing of the humerus of a Binturong Arctictis binturong (Raffles, 1822), which is another tree-climbing mammal, with a similar humerus shape.
The long and short of it is that I still don’t know what specimen this mystery object came from, but I now have a fresh perspective for renewing my search, thanks to the people who get involved with the Friday mystery object. I will let you know if I get any further in my search for an identification, but I owe you all a big thanks for contributing!
Zygoma 