Sauropod Vertebra Picture of the Week

This is a caudal vertebra from the middle of the tail of an ostrich, LACM Bj342:

The middle row shows it in anterior, left lateral and posterior views; above and below the anterior view are the dorsal and ventral views. It’s about 5 cm across the transverse processes. (This figure is from a manuscript that Matt and I will submit to a journal probably within 24 hours.)

In compositing the different views, I had a heck of a time recognising what was what. The dorsal view looks so much more like what we’d expect a ventral view to look like — indeed, the two are more similar for this vertebra than for any other I’ve seen.

How about those big pnuematic foramina right at the top of the bone? At first, Matt and I thought we’d never seen anything like that before. But then we realised that we sort of had — in a cervical vertebra of Apatosaurus which appears as part one of Taylor and Wedel (2013: figure 9).

This is Apatosaurus sp. OMNH 01341 in right posterodorsolateral view. “las” marks a ligament attachment site — a big, baseball-sized rugose lump — and right next to it is a pneumatic foramen, marked “pfo”.

Just like this, the ostrich caudal is a saurischian vertebra with a bifid neural spine, and with pneumatic foramina within the intermetapophyseal cleft.