The first record of a sauropod dinosaur from the Late Cretaceous phosphates of Morocco

Abstract

Sauropod dinosaur remains have been discovered recently in the Late Cretaceous (Maastrichtian) phosphatic deposits of the Oulad Abdoun Basin, near Khouribga (central Morocco). The material consists of right hindlimb bones (femur, tibia and fibula) from a small-sized individual. The marine associated fauna, mainly selachians, actinopterygians, turtles, mosasaurids and plesiosaurs, suggests a marine depositional environment, so that the dinosaur remains may be a remnant of a floating carcass. The femur exhibits a prominent lateral bulge on the proximal one-third, a diagnostic feature of Titanosauriformes. The Moroccan sauropod lacks synapomorphies of Titanosauria and less inclusive clades (i.e., distal tibia expanded transversely to twice mid-shaft breadth; femoral distal condyles angled dorsomedially relative to the shaft); therefore, it is here assigned to a basal titanosauriform as Titanosauriformes indet. This is the first sauropod reported from the Maastrichtian of Morocco and one of the few dinosaur records from the uppermost Cretaceous formations of northern Africa. This discovery confirms the wide geographical distribution of Titanosauriformes during the Late Cretaceous and supports their survival into the Late Maastrichtian of Africa.