Leatherback sea turtle million years ago during the Cretaceous period. The dermochelyids are relatives of the family Cheloniidae, which contains the other six extant sea turtle species. However, their sister taxon is the extinct family Protostegidae that included other species that did not have a hard carapace. Leatherback turtles have the most hydrodynamic body design of any sea turtle, with a large, teardrop-shaped body. A large pair of front flippers powers the turtles through the water. Like other sea turtles, the leatherback has flattened forelimbs adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The leatherback's flippers
Loggerhead shrike sex an adult loggerhead shrike in the field, as they are sexually monochromatic. However, several studies have reported sexual dimorphism in plumage and size traits. Juveniles possess a paler gray plumage that is subtly vermiculated. The loggerhead shrike can be distinguished from the northern shrike by its smaller size, darker grey plumage and larger black face mask that covers the eye completely. It also has a shorter bill with less prominent hook. Their calls are similar. Their vocal range is broad and varied, and has been described as harsh and jarring. The shrike’s notes include squeaky whistles, shrill trills, guttural