Two Eocene chelonioid turtles from Northland, New Zealand

Abstract

The partial skeletons of two marine turtles are reported from Late Eocene strata of Northland, northern New Zealand. One, from the autochthonous Ruatangata Sandstone near Whangarei, is identified as a new species of the previously monotypic cheloniid genus Eochelone Dollo, 1903. It is larger than the European type species, E. brabantica Dollo, 1903. The new species, E. monstigris, represents a geographic range extension for Eochelone and for the group of ‘Eocene stem cheloniines’ to which it belongs, a long-distance interchange that the configuration of Late Eocene–Early Oligocene marine currents and land-sea distribution must have permitted. The other specimen, from the allochthonous Pahi Greensand of northeast Kaipara Harbour, was previously reported as a cheloniid but we believe it more likely to belong to the Toxochelyidae. Given previous records of two dermochelyids (Psephophorus and Maoriochelys), the Middle to Late Eocene of New Zealand hosted at least four species of marine turtle which approaches the modern diversity of five species.