When San Antonio was an ocean: the first record of mosasaurs from the Late Cretaceous of San Antonio, Bexar County, Texas.

During the Cretaceous Period, a shallow inland sea divided North America in two, resulting in much of Texas being covered by the Western Interior Seaway. These ancient waters were dominated by gigantic marine lizards called mosasaurs. Mosasaurs were one of the more successful group of reptiles during the Mesozoic. In less than 35 million years, they went from very small semi aquatic lizards to the apex predators of the world’s oceans. Recent fossil discoveries show that these top marine predators once called San Antonio home 83 million years ago.