Genus: Unaysaurus LEAL, AZEVEDO, KELLNER & DA ROSA, 2004
Etymology: From Tupy (indigenous Brazilian tribe), unay (u-na-hee), meaning Agua Negra (black water); and Greek, sauros, "lizard"; Black Water Lizard.
= Genus: Nova AZEVDO, ROSA, BOELTER & LEAL, 1999, KELLNER, AZEVDO, ROSA, BOELTER & LEAL, 1999

Species: tolentinoi LEAL, AZEVEDO, KELLNER & DA ROSA, 2004
Etymology: In honor of Mr. Tolentino Flores Marafiga (Aqua Negra Locality, Sao Martinho da Serra City, Ro Grande do Sul State), who discovered the species.

Holotype: UFSM 11069

Locality: Agua Negra locality, Agua Negra District of the Town Sao Martinho da Serra, 13 km north of Santa Maria, Rio Grande do Sul State, Brazil.

Horizon: Caturrita Formation.

Biostratigraphy:

Age: Carnian-Norian Stage, Upper Late Triasisc Epoch, Late Triassic.

Material: Skull and lower jaw, axis, 10 dorsal vertebrae, including some ribs, fragmentary gastralia, 30 caudal vertebae, including some chevrons, both scapulae, coracoid, humeri, ulnae, and radii, metacarpals, and most elements of the right manus (including parts of the claws), incomplete tibiae, right astragalus, left metatarsals and some pedal elements.