Last week I gave you this slender bone to try your hand at identifying:

You didn’t have much to go on, but most of you recognised that it’s a fibula (well spotted Ric Morris, Kevin, Mieke Roth and Flick Baker) and I was impressed by the variety of clever clues used to communicate that knowledge. However, Michelle went a step further and identified this as being from a large felid, in the size range of a Mountain Lion, earning loads of bonegeek points.

It took me a little while to work out what this was myself, since it was in a box with Ostrich bones and my first thought was that it might be from another bird. It has articulations at either end and a long midshaft, so it was obviously one of the long bones, but it’s very slender and wouldn’t be able to carry much weight on its own, so it was either a radius or fibula.

I started by looking at the radii of a some large birds, like Albatross and Flamingo. However, on comparison with a few specimens it became obvious that I was looking in the wrong area, since the articulations didn’t fit with those on a bird radius at all. They also didn’t fit the shape of any mammal radius I could think of, so I started considering fibulae.

I knew it couldn’t be a bird fibula, since they are fused with the tibiotarsus and would lack an articulation at the distal end, so I started looking at mammals. It was a bit slender for a dog, but pretty similar to a cat, if on the big side.

Then I remembered that I had a box of postcrania from the same collection as the Ostrich that this bone shared a box with. So I checked the mystery object against that and was pleased to find that there was only one fibula in that box, it was from the other leg and it was a mirror image. So it looks like this bone has not only been identified, but reunited with the Cheetah Acinonyx jubatus (Schreber, 1775) skeleton it came from!

Cheetah in Kruger National Park (South Africa). Image by Mukul2u, 2008