Eukaryota : Metazoa : Bilateria : Deuterostomia : Vertebrata : Tetrapoda : Diapsida : Archosauria : Dinosauria : Theropoda


Spinosaurus aegypticus, hence Spinosauroidea, was the earliest known representative of the group, but the original Egyptian specimen (mostly bits and pieces) was destroyed in WWII. It was once the only unique African theropod known — field research by paleontologist Paul Sereno of the University of Chicago has shown that there is a great diversity of unique African theropods, many of which show relationships with North American specimens; such as Afrovenator abakensis, which is similar to Allosaurus. These new dinosaurs are providing glimpses into what evolutionary events were occuring in Africa (compared to North America) while the continents were splitting apart. Thus, theropods show us something about how evolution works!

Spinosauroids appeared in the Middle Jurassic and survived into the Late Cretaceous. Other spinosauroids include Torvosaurus from North America and Portugal, Baryonyx from England and Spain, Suchomimus from Niger, and Irritator from Brazil.

Spinosauroids are classified based on several skull specializations. These include a very long skull which is over 2.5 times as long as it is tall and conical teeth with a circular cross-section, much like those of a crocodile. Generally, theropods have serrated, blade-like teeth so spinosauroids are somewhat unique in this respect. The conical teeth suggest that spinosauroids may have fed on fish.

Portions of this page created by John Hutchinson 11/1995; modifications and additions since 2005 by David Smith.