Third phalanx

Equus cabalus

Finally got to sit down and do some recording of bones today. It took quite a while to get going; I'd start, then realise that I had forgotten to get the form for recording butchery marks. Print that out and photocopy 30 sheets, sit down again, realise that I'd forgotten another sheet. Rinse and repeat.
It was rather embarrassing as I was supposed to be teaching some students at the same time. Eventually, by the end of the day, I had everything sorted and had remembered most of what was automatic six or seven years ago....

It's a horse's hoof.