Ca4 - Spinosaurus aegyptiacus neotype

3D ModelNoAI

4th caudal vertebra of the Spinosaurus aegyptiacus neotype, FSAC-KK 11888.

At the level of Ca4, the bony core of the tail is wide; about 50 cm across the transverse processes, with a dorsoventral height of 51 cm without the chevron (as preserved - the tip of the spine is missing), and about 70 cm including this element. These proportions clearly indicate that the basal portion of the tail was relatively expanded (both transversely broad and dorsoventrally deep).

A complex of vertebral laminae and fossae is present in the neural arches of the proximal caudal vertebrae and partly persists distally to the mid-caudal neural arches. Ca4 provides the best example (see Ibrahim et al 2020: fig. 2).

The specimen is housed in the palaeontological collections of the Université Hassan II, Aïn Chock, Casablanca, Morocco.

Reference: Ibrahim N. et al. (2020). Tail-propelled aquatic locomotion in a theropod dinosaur. Nature, doi.org/10.1038/s41586-020-2190-3.