👉 Selachoidei, also known as selachians or marine ichthyosaurs, are a group of marine reptiles that lived during the Cretaceous period and were part of the group called "Pterosauria". These creatures had a streamlined body shape with sharp teeth and claws. They were primarily aquatic animals but could also be found on land. Some examples of selachoidei include the sea turtle, the sea snake, and the sea iguana.