Oksoko

Oksoko is a Late Cretaceous oviraptorid recovered from the Nemegt Formation of Mongolia. Reaching approximately two metres in length, it had a tall cranial crest, a sharp, toothless beak, and a robust body. Its most distinctive anatomical feature is its forelimbs: unlike most theropods, which possessed three functional claws, Oksoko had only two functional fingers, with the third reduced to a tiny vestigial remnant. The holotype was discovered alongside three other juvenile individuals preserved in a resting pose, demonstrating that young oviraptorids were gregarious animals that roosted together for warmth or safety. Oksoko was likely an opportunistic omnivore, using its shearing beak to feed on plants, hard seeds, and small prey.

It only possessed two functional fingers on each hand, demonstrating evolutionary digit reduction.

Where and when

Oksoko lived in the Late Cretaceous, from 70 to 66.8 million years ago (Maastrichtian age). Its remains come from Mongolia, in the Nemegt Formation.

The numbers

Length 1.9 m (estimates run from 1.8 to 2 m). Mass about 39 kg. Hip height about 0.8 m. That is 1.1 human-lengths, or 0.17 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Oksoko with a bus Place on the timeline