Hovasaurus (Greek for "Hova lizard"); pronounced HOE-vah-SORE-us
Shallow waters of Madagascar
Late Permian-Early Triassic (255-245 million years ago)
Size and Weight:
About 20 inches long and a few pounds
Broad, flat tail; webbed feet
No sooner had the first prehistoric amphibians evolved into the first true reptiles than some of these "advanced" creatures returned to a marine lifestyle. Hovasaurus is important for being one of the first diapsid reptiles to return to the water (diapsids, which have two characteristic holes in their skulls, comprise dinosaurs, crocodiles and modern birds). Befitting its marine environment, Hovasaurus possessed a long, undulating, tetrapod-like tail, and there's also evidence that it swallowed small stones as ballast, so it could feast on tasty marine organisms near the sea floor. Significantly, Hovasaurus (and its fellow diapsids) survived the end-Permian extinction event that doomed most of its anapsid relatives.