• lower jaw morphology;
  • dentition;
  • phylogeny

Abstract:  A new genus and species of Devonian tetrapod has been identified from material collected in 1947 from the southern slope of Mt. Celsius, Ymer Ø, North-East Greenland. The specimen preserves both lower jaws, partial palate, premaxillae and maxillae, with a natural mould of parts of the shoulder girdle. The new taxon, Ymeria denticulata, shows differences in dentition, skull ornament and lateral line expression from both Acanthostega and Ichthyostega, but it shows a closer resemblance to the latter. A cladistic analysis not only suggests that Ymeria lies adjacent to Ichthyostega on the tetrapod stem, but also reveals substantial topological instability. As the third genus and the fifth species of tetrapod identified from North-East Greenland, it demonstrates the high diversity of Devonian tetrapods in that region.