The specific epithet is derived from Latin pileus 'hat' and from Latin rivalis 'brook', in reference to the nearby township of Hat Creek, Wyoming, U.S.A.[1] Xenocranium pileorivale was a highly specialized animal that was convergent with the talpids, golden moles and marsupial mole.

It possesses many traits indicative of the lifestyle of a subterranean burrower, including small eyes, an upturned snout, muscular arms with large attachment points for the triceps, teres major, and carpal and digital flexor muscles.

[3] The holotype of Xenocranium pileorivale was recovered from the Brule Formation, 160 feet below the top of the Oligocene outcrop in the area,[1] which correlates with the Chadronian age to the Orellan age under the NALMA classification.

[3] The animals from these formations constitute the White River Fauna, which included predators like Archaeotherium and Hyaenodon, and a large diversity of herbivorous mammals, such as the archaic horse Mesohippus, the cursorial rhinoceros Hyracodon, and the very common "oreodont" Merycoidodon.

[4] The phylogenetic relationships of genus Xenocranium is shown in the following cladogram:[5][6][7] Pan-Carnivora Pholidota (sensu stricto) †Escavadodontidae †Melaniella †Ernanodontidae †Metacheiromys †Metacheiromyinae †Palaeanodon †Brachianodon †Mylanodon †Propalaeanodontinae †Arcticanodon †Alocodontulum †Auroratherium †Pentapassalus †Tubulodon †Dipassalus †Tetrapassalus †Xenocranium pileorivale †Epoicotherium †Molaetherium †Epoicotheriidae†Amelotabes