<i>Issi saaneq</i> gen. et sp. nov.—A New Sauropodomorph Dinosaur from the Late Triassic (Norian) of Jameson Land, Central East Greenland

oleh: Victor Beccari, Octávio Mateus, Oliver Wings, Jesper Milàn, Lars B. Clemmensen

Format: Article
Diterbitkan: MDPI AG 2021-11-01

Deskripsi

The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in 1994 and were assigned to <i>Plateosaurus trossingensis</i>. However, continuous new findings of early non-sauropod sauropodomorphs around the globe facilitate comparisons and allow us to now revise this material. Here, the non-sauropod sauropodomorph <i>Issi saaneq</i> gen. et sp. nov. is described based on two almost complete and articulated skulls. The two skulls represent a middle-stage juvenile and a late-stage juvenile or subadult. <i>Issi saaneq</i> differs from all other sauropodomorphs by several unique traits: (1) a small foramen at the medial surface of the premaxilla; (2) an anteroposteriorly elongated dorsoposterior process of the squamosal; (3) a relatively high quadrate relative to rostrum height; (4) a well-developed posterodorsal process of the articular. These features cannot be explained by taphonomy, ontogeny, or intraspecific variation. <i>Issi saaneq</i> shows affinities to Brazilian plateosaurids and the European <i>Plateosaurus</i>, being recovered as the sister clade of the latter in our phylogenetic analysis. It is the northernmost record of a Late Triassic sauropodomorph, and a new dinosaur species erected for Greenland. <i>Issi saaneq</i> broadens our knowledge about the evolution of plateosaurid sauropodomorphs.