Sauropod Vertebra Picture of the Week

Here’s a photo that – for several reasons – I find interesting (and I hope you agree). It depicts the neck base and pectoral skeleton of the Camarasaurus mounted in London’s Natural History Museum (and is thus © NHM). I should say to begin with that the specimen is a notorious composite, combining the bits of several different-sized animals (and with some parts duplicated from the same individual). This explains why the more anterior of the cervical vertebrae look strangely narrower than the more posterior ones (in a natural series of cervicals, the vertebrae became gradually broader the further posteriorly you travel along the sequence), and why the cervical ribs are all over the place and not neatly in alignment, lying in contact for part of their length. Anyway…

We’ve seen in previous posts here (e.g., Matt’s Russian doll post on Apatosaurus) that at least some sauropods had shockingly broad cervical vertebrae, the transverse processes and cervical ribs combining to form great ‘handles’ sweeping out laterally from the sides of the vertebrae (if you need help with those terms go to Tutorial 2). This mount is nice in showing how wide the neck base was in broad-necked taxa like Camarasaurus and Apatosaurus: rather than having subparallel lateral margins and in being narrow along its length (like a swan’s neck), the neck is damn near half the width of the thorax at its base, and then gradually tapers anteriorly. Camarasaurus cervical vertebrae are interesting in lots of other ways (did I mention the particularly large prezygapophyses and bifid neural spines?), but that’ll do for now.