Genus: Tirotherium MONTELLANO-BALLESTEROS & FOX, 2015
Etymology: Latin, tiro, "apprentice" (noun, masculine); in reference to the early stage of tribosphenic evolutin this taxon represents; and Latinzed Greek, therium, therion, (neuter), "beast or wild animal," a common suffix in mammalian generic names.

Species: aptum MONTELLANO-BALLESTEROS & FOX, 2015
Etymology: Latin, aptus (adjective), "adapted"; as presumably this species was for its way of life. 

Holotype: UALVP 29421

Locality: MR-6, Verdigris Coulee, 20 km east of Milk River, Warner County, Alberta Province, Canada.

Horizon: Upper part of Milk River Formation.

Biostratigraphy:

Age: Late Santonian to Early Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous (PAYENBERG et al., 2002) or Aquilian age, Lower Campanian Stage, Aquilian in age, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material: Right upper molar.

 Referred material:

Locality: Localities 12, 20, Verdigris Coulee, 20 km east of Milk River, Warner County, Alberta Province, Canada.

Horizon: Upper part of Milk River Formation.

Biostratigraphy:

Age: Late Santonian to Early Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous (PAYENBERG et al., 2002) or Aquilian age, Lower Campanian Stage, Aquilian in age, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material:

UALVP 29419, 29430, UALV 29426: Left upper molars.

UALVP 29425: Right upper molar.

UALVP 29417, UALVP 29423: Right lower molars.

UALVP 29422: Left lower molar.