H. willetti is known from a single
holotype specimen, BMNHB 001876 from the
Wealden Group of the
Isle of Wight that includes a well-preserved nearly complete
skull. It was assigned to a new species of
Goniopholis,
Goniopholis willetti, by Salisbury and Naish in
2011 honoring its collector. A broad
phylogenetic analysis of crocodyliforms published the same year by Andrande
et al. (2011), found the specimen to be the
sister taxon of the clade formed by
Anteophthalmosuchus hooleyi and the unnamed "Dollo's goniopholidid". Thus it was reassigned to its own genus by Buscalioni
et al. (2013), creating the
combinatio nova,
Hulkepholis willetti. The
generic name honors
John Whitaker Hulke who described the specimen as belonging to
Goniopholis. A second species,
Hulkepholis plotos, was first described and named by A.D. Buscalioni, L. Alcalá, E. Espílez and L. Mampel in
2013. The
specific name is derived from
Greek mythology πλοτός,
plotos, the drifter. It is known solely from the
holotype AR-1/56, a partial
skeleton which consists of AR-1-2045, a nearly complete but crushed skull; AR-1-2048, 4859, 4860, three
vertebrae; AR-1-2046, a
rib; AR-1-2048, a metapodial; and AR-1-2049, 4861, 4862, three
osteoderms. It was collected from the early
Albian-aged
Escucha Formation, at Santa Maria Mine located in the municipality of Ariño,
Teruel Province, of
Aragon, along with the closely related
Anteophthalmosuchus escuchae. ==Phylogeny==