What is "pandermochelys"

Pandermochelys is a clade of sea turtles belonging to the superfamily Chelonioidea. It is defined as all turtles more closely related to leatherback sea turtles than to cheloniids ( green sea turtles and relatives). It includes the largest living turtles, the leatherback sea turtle, as well as the largest sea turtles of all time, Archelon.