Figure 1. Vertebral fossae in the sauropod dinosaur Rapetosaurus krausei.

Vertebral fossae in sauropods are hypothesized to be produced by pneumaticity, which is usually limited to the axial column, excluding the atlas, chevrons, and distal caudal vertebrae (bottom image). The middle photograph shows fossae in a cervical vertebra, which in the neural arch are bounded by vertebral laminae. The close-up photograph (top) shows the that bone texture within the fossa is often smooth, crenulated, and shiny, which is indicative of pneumatic bone. Silhouette reconstruction from [49]; cervical vertebra from [59]:fig. 10). Scale bar equals 1 m in silhouette; scale bars equal 3 cm in photographs. ©Copyright 2009 The Society of Vertebrate Paleontology. Reprinted and distributed with permission of the Society of Vertebrate Paleontology.