Classification: Dinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Megalosauroidea, Megalosauria, SpinosauridaeÂ
Ostafrikasaurus is our first Spinosaurid, and lemme tell you, my boyfriend Max's favorite dinosaur group is the Spinosaurids, so he's hella freaking excited about this. It was from the mid Tithonian stage of the Late Jurassic, about 148 to 145.5 million years ago, and is known from an isolated tooth. It was found in the Tendaguru Formation in Tanzania. It was originally described in 1920 as belonging to the genus Labrosaurus, but then that was assigned to Allosaurus, but this tooth was not similar to Allosaurus, so it was instead labeled as Ceratosaurus. Finally, since none of these were a perfect match, it was given a new genus in the spinosaurids. As such, we don't know a lot about this guy, given its size is pretty much unknown, we aren't sure about what it ate, and what it looked like isn't exactly known. However, it is the oldest known spinosaurid, based on the fact that the tooth displays enamel ornamentation similar to Baryonyx and other baryonychines, but it was different enough that it was a fairly basal spinosaurid. It had more denticles (serrated units) than later spinosaurids, indicating that spinosaurid evolution was characterized by a reduction in denticles. If it was like later spinosaurids, it had a crocodile like snout, or in other words very long and narrow. It might have had enlarged claws on its hands, and/or a sail on its back like later spinosaurids; however, since little is known about this dinosaur, more remains will need to be found before more can be said about it. It lived alongside such dinosaurs as Kentrosaurus, Dicraeosaurus, Giraffatitan, and Elaphrosaurus.Â
