Koreanosaurus

Koreanosaurus was a small herbivorous dinosaur discovered in Late Cretaceous strata of South Korea. Measuring around two metres from snout to tail, it belonged to the orodromines, a subfamily of small, nimble ornithopods. Koreanosaurus stands out due to its disproportionately heavy shoulders, thick upper arm bones, and elongated hands. These unusual anatomical features suggest it was adapted for a fossorial or semi-fossorial lifestyle, capable of digging extensive underground burrows for shelter or rearing young, similar to its close North American cousin Oryctodromeus. While most related ornithopods were obligate bipeds built for running, Koreanosaurus may have frequently moved on all fours. Feeding low to the ground on roots, shrubs, and ferns, this intriguing dinosaur offered valuable proof that specialized burrow-dwelling behaviours occurred widely across diverse dinosaur lineages.

Its exceptionally robust shoulder girdle and forelimbs strongly suggest it was adapted for digging burrows.

Where and when

Koreanosaurus lived in the Late Cretaceous, from 85 to 80 million years ago (Santonian-Campanian age). Its remains come from South Korea, in the Seonso Conglomerate.

The numbers

Length 2.2 m (estimates run from 2 to 2.4 m). Mass about 35 kg. Hip height about 0.7 m. That is 1.3 human-lengths, or 0.2 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, first ma, last ma, hip height.

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