Genus: Ahvaytum LOVELACE, KUFNER, FITCH, CURRY RIGERS, SCHMITZ, SCHWARTZ, LeCLAIR-DIAZ, St. CLAIR, MANN & TERAN, 2025
Etymology: Shoshone, A va-tum, "long ago", in reference to the ancient nature of UWGM 1975.

Species: bahndooivche LOVELACE, KUFNER, FITCH, CURRY RIGERS, SCHMITZ, SCHWARTZ, LeCLAIR-DIAZ, St. CLAIR, MANN & TERAN, 2025
Etymology: Shoshone, ban-doi-ve-che, 'water's young handsome man': In reference to the colourful salamanders found in the region, and also means dinosaur, which is the meaning used here. The name Ahvaytum bahndooivche ('long ago dinosaur' is the product of a multigenerational collaboration between the Fort Washakie Schools 7th grade cohort (2022), educators, Eastern Shoshone Tribal Historic Preservation Office, adn Tribal Elders.

Holotype: UWGM 1975

Locality: Garrett's Surpries (after undergraduate field assistant Garrett Johnson who discovered the locality), Fremont County, Wyoming.

Horizon: Popo Agie Formation.

Biostratigraphy:

Age: Otischalkian, Late Carnian Stage, Lower Late Triassic Epoch, Late Triassic.

Material: Isolated left astragalus.

Ahvaytum bahndooivche after LOVELACE, KUFNER, FITCH, CURRY RIGERS, SCHMITZ, SCHWARTZ, LeCLAIR-DIAZ, St. CLAIR, MANN & TERAN, 2025: A) medial; B, C) lateral: D, J) posterior: E, H) distal; F) proximal; I) anterior and J) posterior orthographic views.

Referred material:

UWGM 7549: Proximal end of left femur.

UWGM 7549 Ahvaytumbahndooivche after LOVELACE, KUFNER, FITCH, CURRY RIGERS, SCHMITZ, SCHWARTZ, LeCLAIR-DIAZ, St. CLAIR, MANN & TERAN, 2025: A) anteromedial; G) posterolateral; C) proximal; D) anterolateral and E) posteromedial orthographic views.