1.5m (5ft) long

A jaw fragment of Obruchevichthys gracilis was recovered from Upper Frasnian (Late Devonian) deposits in Latvia. This specimen, originally identified as a lobe-fin fish, was reclassified as a tetrapod after Per Ahlberg reported that it shared many diagnostic features with the jaw of Elginerpeton, a tetrapod of similar age from Scotland.

Aquatic predator

Late Devonian Latvia

Obruchevichthys and Elginerpeton predate the other Late Devonian tetrapods by 5-8 million years. This, and the fact that both tetrapods share several unique features, suggest that they represent a distinct and presumably short-lived radiation that diverged prior to the emergence of other tetrapods.