Editor's Summary

16 October 2008

Fins to limbs: joining the dots

Details of the morphological changes involved in the vertebrate transition to land — including the order in which they occurred — are sparse. The fossil record is too sketchy to give a feature-by-feature timeline, but by examining multiple specimens of the braincase of the Devonian fossil Tiktaalik roseae, a transitional form between fishes and tetrapods, Downs et al. have filled in some of the gaps. Although primitive in many respects, some of T. roseae's features nod to the tetrapod state. And by reference to this new view of Tiktaalik morphology, the transition from finned to limbed fossil forms can be more readily understood.

Article: The cranial endoskeleton of Tiktaalik roseae

Jason P. Downs, Edward B. Daeschler, Farish A. Jenkins & Neil H. Shubin

doi:10.1038/nature07189

Abstract | Full Text | PDF (1,111K) | Supplementary information