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

I thought it looked a bit like an Ewok’s weapon, but fairly obviously it’s a bit of some critter’s leg. The question is, which critter?

In comments by David M Watson, David Hone, taihaku and palfreyman1414  it was quickly recognised as being from a ratite (the group of flightless birds that include Emus, Cassowaries, Kiwis, Rheas and Ostriches – plus some extinct examples like Moas and Elephant Birds), but it was henstridgesj who narrowed it down to a tarsometatarsus (fused ankle and foot bones) of the correct ratite – the Ostrich Struthio camelus Linnaeus, 1758.

The size is a bit smaller than you’d expect for an adult Ostrich and the top of the bone (the bit on the left) is less well fused, so it appears to be from a subadult individual. The reason it can be distinguished from some of the other suggested ratites is all down to the number of trochlea (the rounded and grooved end bits that the toes attach to). Ostriches only have two toes, whereas the other ratites have three or four and this is reflected in those trochlea.

Ostrich foot showing the two toes. Image by Tony Wills (2007)

So well done to everyone who took part, especially henstridgesj who was spot on!