Sauropod Vertebra Picture of the Week

Ventral, to be precise. Here are the first few cervicals of Cetiosaurus oxoniensis, from the mounted skeleton in the Leicester City Museum. A more typical lateral view is shown below. Forget about the skull, it’s plastersaurus.

We tend to think of vertebrae as cylinders with weird bits hanging off, and in most mammals that’s true. (Incidentally, the next time you eat a t-bone steak, have a look at the bone. It’s one half of a lumbar [non-rib-bearing trunk] vertebra. Proof at the bottom of the post.) But sauropod vertebrae are wacky, and nowhere more so than in the neck. The condyle and cotyle are round and point to the ancestral cylindrical state, but the centrum in between is often nothing like a cylinder. First, it is frequently waisted–narrower in the middle than at the ends, like an hourglass–as you can see in the ventral view at top. Second, the ‘walls’ of the cylinder are usually so eaten away by pneumatic openings that what is left looks like more like an I-beam or stick person in cross-section. So sauropod cervicals are often only round where they have to be–where they fit together.

Hey, look, something red for Valentine’s Day! Awwww!