Tetrapod or near-tetrapod fossils from the Upper Devonian of Scotland

Abstract

SINCE 1932, the earliest known undisputed tetrapods have been of uppermost Famennian (late Upper Devonian) age^1–3. Although a probable tetrapod jaw has been described from the Lower Famennian⁴, and tetrapod tracks of supposedly Frasnian⁵ (and possibly earlier⁶) age are known, no fossil limb material older than the latest Famennian has been discovered. The 'panderichthyids'Panderichthys⁷ and Elpistostege⁸ from the Lower Frasnian (early Upper Devonian) are regarded by some8–10 as the closest known sister group of tetrapods, but Panderichthyshas paired fins rather than limbs¹¹. Here, I describe a hitherto unrecognized tibia from the Upper Frasnian (middle Upper Devonian) site of Scat Craig, near Elgin, Scotland^12–14, collected during the nineteenth century, which extends the fossil record of the tetrapod-type hind limb by roughly seven million years¹⁵. Other isolated bones from the same locality also show tetrapod characteristics. The tibia, a humerus and some incomplete jaws are discussed below, but a complete description of the material is in preparation.