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

Since 1932, the earliest known undisputed tetrapods have been of uppermost Famennian (late Upper Devonian) age1–3. 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, Scotland12–14, 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.