plesiosauroid

Plesiosauroid refers to a group of marine reptiles that lived from the late Triassic to the late Cretaceous periods. These creatures were part of the larger sauropterygian group, which were well-adapted to aquatic life. Plesiosaurs are characterized by their long, flexible necks and broad, stout bodies, with limbs modified into flippers for swimming. They possessed long jaws filled with sharp teeth, ideal for catching fish.12

The plesiosauroid lineage is distinguished by its relatively small head and exceptionally long, flexible neck, which could have snakelike proportions. In contrast, pliosaurs, another lineage within Plesiosauria, had shorter necks and larger heads. Some plesiosaurs grew to impressive sizes, with certain species reaching lengths of up to 13 meters (43 feet).1