 In 1930, he described "Amphekepubis", a genus of mosasaur from the Late Cretaceous of Mexico.Their remains correspond to the holotype specimen UM VP 509 (University of Missouri), a partial skeleton preserved in three dimensions, comprising the pelvic area, hind limb bones and nine caudal vertebrae, found in the east of Monterrey, in the state of Nuevo Leon, which come from marine sediments (claystones) apparently from the San Felipe Formation, which corresponds to the boundary between the ages of Coniacian and Santonian in the early Late Cretaceous.However, it has been suggested that age may be more recent and its remains even might belong to the genus "Mosasaurus".