Africa's Aquatic Dinosaur

Last evening, NOVA, on PBS, focused on the discovery and evaluation of Spinosaurus fossils, the largest carnivorous dinosaur yet unearthed and the only one known to have been semi-aquatic.  Larger than Tyrannosaurus rex, Spinosaurus lived in the Saharan Desert region of North Africa, some 95 million years ago.  Its fossils have been found in a layer of late Cretaceous sandstone which also contains the fossils of numerous marine creatures, indicating that a shallow sea covered much of the region during that period.

Characterized by a long, crocodilian snout, relatively large forelimbs and a large, boney fin on its back, Spinosaurus would have been too top-heavy to walk upright like T. rex; indeed, paleontologists have concluded that it was primarily aquatic (scouring the shallows for large fish, sharks and other marine life) and only came ashore to sleep, nest or perhaps to feast on small terrestrial vertebrates.  Its conical teeth and flat feet (both seen in crocodilians) favor this hypothesis.

One of the most interesting aspects of the Spinosaurus story is that fossils of this giant predator were first discovered in Egypt by Ernst Stromer, German paleontologist, but were unfortunately destroyed by a bombing raid during WWII; almost 100 years later, other fossils were dug up in Morocco and sold to a museum in Milan, Italy, setting the stage for the high-tech investigation reported on NOVA.  A full skeleton of Spinosaurus has yet to be found but many surely lie beneath the vast sands of the Saharan Desert.