Genus: Kayentatherium KEMACK, 1982
Etymology: In reference to the Kayenta Formation, Early Jurassic and Greek, theron, “beast, mammal”: Kayenta beast.
= Nearctylodon LEWIS, 1986
Etymology: Neartic and Tritylodon (m): Nearctic tritylodont.

Species: wellesi KERMACK, 1982
Etymology: In honor of Samuel P. Welles.

Holotype: UCMP No. V6897/83671

Locality: San Bernale Locality, Many Farms, Apache County, Arizona.

Horizon: Kayenta Formation.

Biostratigraphy:

Age: ?Sinemurian-Pliesbachian Stage, Middle Lias Epoch, Middle Early Jurassic.

Material: Skull.

Referred material:

UCMP No V6987/83672: Fragmentary palate and badly damaged roots of teeth.

UCMP No. V6987/83672: Fragmentary right lower jaw.

 


Locality: Coconino County, Graces Mesa, Arizona.

Horizon: Kayenta Formation.

Biostratigraphy:

Age: ?Sinemurian-Pliesbachian Stage, Middle Lias Epoch, Middle Early Jurassic.

Material:

UCMP No. 72056/97756: Fragmentary left lower jaw with teeth.

 


SUES, 1986

Locality: Northern Arizona.

Horizon: Kayenta Formation.

Biostratigraphy:

Age: ?Sinemurian-Pliesbachian Stage, Middle Lias Epoch, Middle Early Jurassic.

Material:

MCZ 8812: Skull and dentary and partial skeleton.

MCZ 8811: Fragmentary skull.

USNM 317203: Skull and dentary of a juvenile.

 


= Nearctylodon broomi LEWIS, 1986
Etymology:

Holotype: USNM 317201

Locality: Us Geological Survey Fossil Vertebrate Locality D1 on Comb Ridge, 11.4 km airline, bearing 069" true, Kayenta, Navajo County, Arizona.

Horizon: Kayenta Formation.

Biostratigraphy:

Age: ?Sinemurian-Pliesbachian Stage, Middle Lias Epoch, Middle Early Jurassic.

Material: A nearly complete articulated skeleton with skull and mandible.

Referred material:

USNM 317202, 371207, 317208: Skull and skeleton.

USNM 317209, 317210: Skulls, mandibles and cervical vertebrae.

USNM 317203, 317205, 317206: Skulls and mandibles.

USNM 317204, 317211, 317212, 317213, 317214: Fragmentary skulls and lower jaw fragments.