Morphology and paleoecology of the oldest lobster-like decapod, Palaeopalaemon newberryi Whitfield, 1880 (Decapoda: Malacostraca)

Palaeopalaemon newberryi Whitfield, 1880 is redescribed based upon a large collection of specimens including those collected in the nearly 40 years since P. newberryi was last evaluated. Previously undescribed aspects of its morphology include a large, pectinate maxilliped; the dactylus of pereiopod I; a triangular sternal field; well-preserved antennae, including an endopod with an antennulate flagellum; and a broad, roughly triangular scaphocerite. Phylogenetic analysis supports the position of P. newberryi as a lobster and suggests that Palaeopalaemonoidea is the sister taxon of Polychelida. Palaeopalaemon newberryi is distinct from Angustidontus, and pectinate claws shared by the two taxa may be a convergent morphology and not phylogenetically informative. Palaeopalaemon newberryi probably exhibited a benthic habit.