A near-tetrapod from the Baltic Middle Devonian

The tetrapodomorph sarcopterygian Livoniana multidentata gen. et sp. nov, i s described on the basis of lower jaw fragments from the Middle Devonian (l ate Givetian) of Latvia and Estonia. It possesses a suite of derived charac ters previously only known from tetrapods, which first appear in the late D evonian (late Frasnian), and a phylogenetic analysis places it on the inter node between Panderichthys and the base of the Tetrapoda. The analysis also reveals that the 'Elpistostegalia' are paraphyletic to Tetrapoda, with Elp istostege closer to tetrapods than is Panderichthys. Owing to incompletenes s of the material, there is almost no overlap between the data sets for Elp istostege and Livoniana; the analysis places the two genera in an unresolve d trichotomy. In addition to the tetrapod features, Livoniana has a strikin gly autapomorphic dentary dentition comprising multiple tooth rows. It thus provides evidence both for the unexpectedly early evolution of tetrapod ch aracteristics and for morphological radiation around the fish-tetrapod tran sition.