It’s a bird, It’s a plane, It’s a plesiosaur!
Plesiosaurs, a group related to lizards, lived in the sea. Although plesiosaurs were not dinosaurs, they became extinct at the end of the Cretaceous, 65 million years ago, at the same time as the non-avian dinosaurs. Plesiosaurs had powerful swimming muscles attached to their expanded shoulder and pelvic bones, and they used their flippers to swim.
This Fossil Friday is Thalassomedon haringtoni, a long-necked plesiosaur with a relatively small head and many sharp teeth for seizing fishes and other marine animals. This long, flexible neck, with as many as 70 vertebrae, probably helped in grasping such rapidly moving prey.
Find Thalassomedon swimming overhead in the Hall of Vertebrate Origins.