Ostafrikasaurus

Ostafrikasaurus is a genus of spinosaurid theropod dinosaurs known from the Jurassic of Tendaguru, southeastern Tanzania. It contains a single species, Ostafrikasaurus crassiserratus.

Ostafrikasaurus is only known from the holotype specimen MB R 1084, an isolated tooth. It was originally referred to Labrosaurus? stechowi by Werner Janensch in 1920. All teeth assigned to L.? stechowi were collected by German expeditions from 1909 to 1913 from the area around Tendaguru hill in southeastern Tanzania, German East Africa. Janensch (1925) described a total of nine teeth, which he assigned to L.? stechowi (holotype MB R 1083) and divided them into five types. Later the teeth were reassigned to ?Ceratosaurus stechowi, as Labrosaurus found to be a junior synonym of Allosaurus. Recent studies usually suggest that Labrosaurus stechowi is a nomen dubium, and that these teeth are indeterminate, perhaps representing different taxa.

MB R 1084, which is the only teeth from the Upper Dinosaur Marl (Obere Dinosauriermergel) of the Tendaguru Formation, differs in several respects from the other teeth, from the Middle Dinosaur Marl (Mittlere Dinosauriermergel). Although Buffetaut in 2008 suggested that another isolated tooth, MB R 1091 collected from the Middle Dinosaur Marl, may also represent the same genus as MB R 1084, Buffetaut when naming Ostafrikasaurus in 2012 did not refer it to the genus. The Upper Dinosaur Marl of the Tendaguru Formation dates back to the middle and late Tithonian faunal stage of the Late Jurassic, about 148-145.5 million years ago.