Genus: Marasuchus SERENO & ARCUCCI, 1994
Etymology: Generic name refers to the mara, or Patagonian cavy (Dolichotis), a solitarily cavimorph rodent that is quite abundant on the plains of the Camp de Talampaya and around the type locality. The mara, which commonly moves with a totting (four-legged, bouncing) gait, closely resembles long-legged rabbits and hares. The name Marasuchus (mara; souchos (Greek), crocodile) thus retains the spirit of Romer’s original genus Lagosuchus, Greek, lagos, "rabbit" and Greek, souchos, "crocodile."

Species: lilloensis (ROMER, 1972) SERENO & ARCUCCI, 1994
Etymology: In reference to the Instituto Lillo, Tucuman, Argentina.
= Lagosuchus lilloensis ROMER, 1972

Holotype: PVL 3872

Locality: Southwest part of the Los Chanares Locality, “area de Los Chanares, 2 km al SE de la Puerta de Talampaya.”, more accurately located 3 km north of the north branch of Chanares River and 5 km southwest of the Puerta de Talampaya, Talampaya National Park, Chanares beds, Province of La Rioja, Argentina.

Horizon: Lower member of the Chanares Formation.

Biostratigraphy:

Age: Ladinian Stage, Upper Mid Triassic Epoch, Late Triassic.

Material: Back of skull, complete left leg except for phalanges, complete right leg, a series of vertebrae including sacrum and caudal vertebrae.

Referred material:

PVL 4670 Articulated anterior caudal vertebrae lacking chevrons.

PVL 4671: Articulated anterior caudal vertebrae with chevrons.

PVL 4672: Articulated vertebral colum from atlas to the 17th presacral vertebra.

= Lagosuchus talampayensis BONAPARTE, 1975

PVL 3870: Very back of skull, posterior part of premaxilla, maxilla, 9 cervicals, 11 dorsal vertebrae, ilia, pubi, ischia, femur, tibia, fibula, metatarsals, phalanges.

PVL 3871: Scapula and coracoid, humerus, ulna radius, femur.

PVL 3872: Partial braincse and articulated vertebral column form the atlas to the ninth presacral vertebrae.