Atlasaurus

Atlasaurus is a remarkable Middle Jurassic sauropod excavated from the High Atlas Mountains of Morocco. Named in 1999, it is represented by a nearly complete skeleton found in the Guettioua Formation. Atlasaurus stood out from most other contemporary sauropods due to its unusual body proportions: it had elongated forelimbs and hindlimbs combined with a relatively short neck and a large skull. Measuring around fifteen metres in total length and weighing up to fifteen tonnes, it bore superficial resemblances to brachiosaurids, although phylogenetic studies frequently link it to the Turiasauria lineage. Its elevated posture allowed it to browse on elevated vegetation in lush semi-arid Jurassic floodplains.

Atlasaurus had exceptionally long legs relative to its body, giving it a distinctive high-shouldered profile.

Where and when

Atlasaurus lived in the Middle Jurassic, from 168.3 to 163.5 million years ago (Bathonian-Callovian age). Its remains come from Morocco, in the Guettioua Formation.

The numbers

Length 15 m (estimates run from 14 to 16 m). Mass about 15 t. Hip height about 3.8 m. That is 8.8 human-lengths, or 1.34 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

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