Last week I gave you this mystery bone to identify:
As I suspected, it was simultaneously easy and difficult: easy because it’s clearly an os penis or baculum; difficult because it can be hard to narrow down the species to which a baculum belongs without having specimens for comparison. For some reason people can be funny about penis bones and, despite the fact that male animals tend to be over-represented in museums, the baculum will often have been removed or not included in skeletal mounts.
That said, Steph came closest, getting the right family with the clue:
Bac to the bear-minimum I would guess?
If you remember one of my past posts I showed an image of the baculum mounted on the skeleton of a Giant Panda in Berlin (more about this below):
You can see that, although it differs slightly with a bit of a dip towards the tip, it’s rather similar in structure to the mystery object.
Oddly however, it appears that this baculum on the Berlin Panda specimen has been switched for that of a different bear species. Pandas have a very distinctive reduced baculum with wings (see below), that looks nothing like this, which is more similar to the os penis of a Spectacled Bear (or possibly a Polar Bear at a push).
The mystery object is actually the baculum of a Sloth Bear Melursus ursinus (Shaw, 1791).
In future, should you ever find yourself with an unidentified bear penis on your hands, I suggest taking a look at this handy figure by Abella et al. 2013¹:
So in answering one mystery object we’ve uncovered a far bigger mystery – how did the Berlin Panda end up with the wrong penis?
¹Abella J, Valenciano A, Pérez-Ramos A, Montoya P, Morales J (2013) On the Socio-Sexual Behaviour of the Extinct Ursid Indarctos arctoides: An Approach Based on Its Baculum Size and Morphology. PLoS ONE 8(9): e73711. https://doi.org/10.1371/journal.pone.0073711