New discoveries of archosaur and other tetrapod footprints from the Timezgadiouine Formation (Irohalene Member, Upper Triassic) of the Argana Basin, western High Atlas, Morocco - Ichnotaxonomic implications

Abstract

© 2016 Elsevier B.V.New discoveries of tetrapod footprints from the Irohalene Member (T5, Upper Triassic, Carnian) of the Timezgadiouine Formation near Irohalene (Argana Basin, Morocco) are assigned to Parachirotherium isp., Atreipus-Grallator isp. (Dinosauromorpha), Brachychirotherium isp. (crocodylian-stem archosaurs), Apatopus lineatus (phytosaurs) and Rhynchosauroides (lepidosauromorphs/archosauromorphs). Parachirotherium is present on the surfaces with different tetradactyl-pentadactyl extramorphological variations, similar to the preservation mode observed at the type locality of the ichnogenus in the Middle Triassic of the European Germanic Basin. Described specimens permit a re-evaluation of footprints described earlier from the Irohalene locality that are synonymized here with Parachirotherium and Atreipus-Grallator. The presence of Brachychirotherium is the second record in North Africa and Morocco. The assemblage is similar in composition to other T5 localities and to some ichnofaunas in North America and central Europe. Biostratigraphically, the occurrence of Brachychirotherium indicates the respective biochron that can be cross-correlated with the Carnian-Rhaetian interval.