Hypuronector limnaios (n. gen., n. sp.) is a small reptile described from the Late Triassic (Late Carnian) age Lockatong Formation of the Newark basin of New Jersey. It occurs in the laminated, relatively deep-water portions of sedimentary cycles controlled by orbital forcing of climate. Hypuronector has uniquely elongated chevrons that give the tail a fin- or featherlike shape. Hypuronector was a member of the diapsid family Drepanosauridae, along with Drepanosaurus, Megalancosaurus, Dolabrosaurus, and an undescribed form. The tail of Hypuronector was probably used for swimming, although the proportionally long legs suggest that this reptile at least occasionally moved about on land.