Tiktaalik roseae

A lobe-finned fish with a mobile neck and robust fins — a celebrated transitional form between fish and four-limbed animals.

Ellesmere Island, Nunavut, Canada · Late Devonian (c. 375 million years ago)

Tiktaalik roseae was described in 2006 from Late Devonian rocks of Arctic Canada. It combines fish features (scales, fins, gills) with traits seen in early tetrapods (a flattened skull, a neck and sturdy fin bones).

The team chose where to search by predicting the age and environment of rocks likely to preserve such a transition — a clear example of hypothesis-driven fieldwork.