Species: unicus BONAPARTE, 1991
Etymology: Latin, unicus, "alone or solitary"; in reference to metatarsal III, being the largest of the metatarsals.

Holotype: MUCP v 41

Locality: Northern area of Neuquen City, Neuquen Province, Patagonia, Argentina.

Horizon: Bajo de la Carpa Formation, Lower Rio Colorado Subgroup, Upper Neuquen Group.
(was Bajo de la Carpa Member, Rio Colorado Formation.)

Biostratigraphy:

Age: Coloradoan Tetrapoda Assemblage, Age: Santonian-Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Tibia, astragalus, metatarsals II, III and IV, phalanges, 1 and 2 of metatarsal I, phalanges 1, 2 ,3 and proximal end of ungual of metatarsal III, phalanges 1, 2 , 3, 4 and ungual of metatarsal IV.

Referred material:

EGLI, AGNOLI & NOVAS, 2016

Locality: Paso Cordova, Rio Negro Province, Patagonia, Argentina.

Horizon: Bajo de la Capa Formation, Rio Colorado Subgroup, Nequen Group.

Biostratigraphy:

Age: Santonian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material:

MPCN-PV-370: Incomplete left femur, tibia, metatarsals II, III and IV, several pedal non-ungual phalanges, and digit IV pedal claw.