Ancient Marine Reptiles

Vertebrate evolution has led to the convergent appearance of many groups of originally terrestrial animals that now live in the sea. Among these groups are familiar mammals like whales, dolphins, and seals. There are also reptilian lineages (like plesiosaurs, ichthyosaurs, mosasaurs, thalattosaurs, and others) that have become sea creatures. Most of these marine reptiles, often wrongly called "din...