Last week I gave you a guest mystery object from Catherine McCarney, the manager of the Dissection Room at the UCD School of Veterinary Medicine:
The first question I normally try to answer when undertaking an identification is “what kind of bone is this?”, but in this instance it’s not immediately obvious.
There is a broad section with articulation points, a foramen (or at least something that looks like a hole, which might be a foramen) and a flattish section that looks like it probably butts up against something with a similar flat section. This would normally put me in mind of the ischium of a pelvis.
But it’s not a pelvis as the articulations are all wrong and the shape of the skinny piece of bone that projects off doesn’t fit any functional ilium shape that I’m aware of.
The pectoral girdle has a similar set of structural features and this object starts to make more sense with that in mind. Things like turtles and whales may have a structure like this, but there’s something to keep in mind: despite being fairly large, this object only weighed in at 26g.
Turtles and whales have dense bone that helps reduce buoyancy, to make remaining submerged less energetically demanding, but this bone must be full of air spaces – which offers a clue as to likely type of animal it came from. A bird – as Joe Vans noted in the comments.
Considering the size of this object there are very few possible candidates. Most birds are pretty small and this object is pretty big, so we just need to look at some of the Ratites.
The comparisons I managed to find have led me to the conclusion that this is most likely part of the pectoral girdle of an Ostrich Struthio camelus Linnaeus, 1758.
More specifically, I think it’s the coracoid (#2 on image), clavicle (#3 on image), and scapula (#4 on image) from the left hand side of the pectoral girdle of an Ostrich.
I was delighted to see that Wouter van Gestel agreed with this assessment in the comments, since he knows more about bird bones than I could ever hope to learn!
Finally I’d like to thank the fatastic Catherine McCarney for sharing this mystery object from the depths of the Vet School’s collections. I hope you all enjoyed this challenge!