More-complete remains ofProcolpochelys charlestonensis(Oligocene, South Carolina), an occurrence ofEuclastes(upper Eocene, South Carolina), and their bearing on Cenozoic pancheloniid sea turtle distribution and phylogeny

New and more-complete material ofProcolpochelys charlestonensisWeems and Sanders, 2014 provides the first detailed information on the skull, jaw, and plastron of this species, which occurs in the Oligocene Ashley and Chandler Bridge formations near Charleston, South Carolina. This material allows a much more detailed comparison of this turtle with the co-occurring pancheloniid speciesAshleychelys palmeriWeems and Sanders, 2014 andCarolinochelys wilsoniHay, 1923a, as well as with its Miocene successorProcolpochelys grandaeva(Leidy, 1851). Fused dentaries, found in the Cooper River north of Charleston, belong to the pancheloniid genusEuclastes, previously known only from the Upper Cretaceous and Paleocene. This specimen, apparently from the upper Eocene Parkers Ferry Formation, expands the temporal range of this genus and indicates thatEuclastessurvived in the North Atlantic basin far longer than was previously known. These new finds, combined with previous records of fossil pancheloniid sea turtles, provide an improved picture of the temporal distribution, evolutionary trends, and likely phylogeny of pancheloniids from the Late Cretaceous to the present.