Article: A new rauisuchian (Archosauria, Suchia) from the Upper Triassic of the Argana Basin, Morocco
In the 1970s the Upper Triassic strata of the Argana Basin yielded archosaurian remains that were tentatively attributed to the rauisuchian Ticinosuchus. Restudy of this material together with new remains reveal new anatomical data and show that it in fact belongs to a new taxon, Arganasuchus dutuiti gen. et sp. nov. The systematics of the Rauisuchia are still unresolved; nevertheless, a monophyletic suprageneric group can be defined within the probable non-monophyletic rauisuchians. Arganasuchus dutuiti differs from all adequately known rauisuchians in three autapomorphies: acetabular rim on pubis runs anteroventrally parallel to pubic shift rather than being terminal and perpendicular to it; large contribution of pubis to acetabular depression; palatal process of maxillary low and confluent with interdental crest, rather than separated from it by a large area. The maxilla of Arganasuchus resembles those of Batrachotomus and Fasolasuchus in having a Y-shaped rather than a U-shaped form. As in rauisuchids, Arganasuchus dutuiti has short cervical vertebrae and a dorsal border of the proximal extremity of the pubis that is convex in lateral view. It shares one derived character state with Batrachotomus and Postosuchus (a tear-shaped and anteriorly orientated rugosity on the lateral side of the pubis, lying on a deep, longitudinal depression) and one more derived character state with Batrachotomus (narrow ante-acetabular part of the pubis; hence, the anterior border of the proximal extremity of the pubis is almost contiguous with the actabular rim).