A new species of Pygocephalomorpha (Eumalacostraca, Peracarida) from the Leitchfield Formation, Lower Carboniferous (Mississippian) of Grayson County, Kentucky, U.S.A.

We describe a new species of pygocephalomorph eumalacostracan from the Leitchfield Formation, Mississippian (Lower Carboniferous) of Kentucky, U.S.A. The fossils display a well-developed cephalothorax, pleon, and tail fan, and they show greatest affinity with other species within Tealliocarididae, especially to species of Pseudotealliocaris. The new species, Pseudotealliocaris holthuisi, is a second taxon of tealliocarid from the American Lower Carboniferous, the other being P. palinscari from the Mississippian of Pennsylvania. We compare the new species to other known species in the family and provide an overview of pygocephalomorph evolution.