Amygdalodon

Amygdalodon is an early sauropod dinosaur discovered in Chubut Province, Argentina. It lived during the Early to Middle Jurassic period and is notable as the very first Jurassic dinosaur described from the South American continent. Known primarily from fragmentary vertebrae, ribs, pelvic bones, and almond-shaped teeth, it represents a crucial early stage in sauropod evolution. It was a quadrupedal plant-eater with stout limbs and a moderately long neck, estimated to have measured between twelve and fifteen metres in length. Its almond-shaped tooth crowns feature prominent enamel wrinkles suited for shearing tough vegetation. While its incomplete remains make exact relationships tricky to pin down, palaeontologists generally classify Amygdalodon as a basal member of the Eusauropoda.

Amygdalodon was the first Jurassic dinosaur ever described from South America.

Where and when

Amygdalodon lived in the Early Jurassic, from 179 to 170 million years ago (Toarcian-Aalenian age). Its remains come from Argentina, in the Cerro Carnerero Formation.

The numbers

Length 14 m (estimates run from 12 to 15 m). Mass about 6.7 t. Hip height about 3 m. That is 7.9 human-lengths, or 1.21 of a double-decker bus. These are estimates from fragmentary remains; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

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