Genus: Opisthias GILMORE, 1909
Etymology:
= Theretairus SIMPSON, 1926
Etymology:

Species: rarus GILMORE, 1909
Etymology:

Holotype: USNM 2860

Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone 3.

Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material: Left jaw ramus.

Paratype: USNM 2858: Dentary.

Referred material:

SIMPSON, 1926

YPM 13765: Right maxilla.

YPM 13766: Left maxilla.

 

CHURE, 1992, FRASER & WU, 1998

Locality: DNM 400, Dinosaur National Monument, Uintah County, Utah.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone?

Age: Comobluffian age, Stage?, uppermost Malm Epoch, Late Jurassic.

Material:

DINO 15911: Cranial material.

 

Locality: DNM-96 (Quarry 94), Rainbow Park micosite, Dinosaur National Monument West, Rainbow Park Area, Uintah County, Utah.

Horizon: Upper Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone 4.

Age: Upper Part, Comobluffian age, Tithonian Stage, uppermost Malm Epoch, Late Jurassic.

Material:

DINO 13860: Disarticulated partial skull.

Unidentified genus and species A

DINO 14728: Distal end of left ilium.

Unidentified genus and species B

DINO 14729: Pair of ilia.

 

Locality: DMN 307, Dinosaur National Monument, Uintah County, Utah.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone?

Age: Comobluffian age, Stage?, uppermost Malm Epoch, Late Jurassic.

Material:

DINO 15944: Partial skull and postcranium.

 

LEADER & SMALL, 1999

Locality: Wolf Creek Site, Near Massadona, Moffat County, Colorado.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone?

Age: Comobluffian age, Stage?, uppermost Malm Epoch, Late Jurassic.

Material:

DMNH:

 

REYNOSO, 1993

Locality: Huizachal Canyon, Tamaulipas State, Mexico.

Horizon: La Boca Formation.

Biostratigraphy:

Age: Early-Mid Jurassic.

Material:

IGM 3495: Dentary.

 

= Theretairus antiquus SIMPSON, 1926
Etymology: Latin, antiqua, "ancient."

Genholotype: YPM 13764

Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone 3.

Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material: Most of a right dentary.