Noasaurus

Noasaurus was a small, lightly built predatory ceratosaur that lived in what is now northwestern Argentina during the latest Cretaceous period. Discovered in rocks of the Lecho Formation, this agile carnivore measured roughly one and a half to two metres long and weighed around twenty kilograms, making it about the size of a medium dog. It was closely related to the massive abelisaurids but evolved a much more slender, gracile body plan suited for hunting small vertebrates. When first described, palaeontologists believed its large curved claw was an enlarged sickle claw on the foot like that of a dromaeosaur. Subsequent analyses of better-preserved relatives revealed this sharp weapon actually tipped the first finger of the hand. While only fragmentary remains are known, Noasaurus gave its name to an entire family of unusual predatory dinosaurs found across the southern continents.

Its large raptorial claw was originally thought to belong to the foot, but is now recognised as a hand claw.

Where and when

Noasaurus lived in the Late Cretaceous, from 72.1 to 66 million years ago (Maastrichtian age). Its remains come from Argentina, in the Lecho Formation.

The numbers

Length 2 m (estimates run from 1.5 to 2.4 m). Mass about 23 kg. Hip height about 0.6 m. That is 1.2 human-lengths, or 0.18 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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