Genus: Thadeosaurus CARROLL, 1981
Etymology:

Species: colcanapi CARROLL, 1981
Etymology:

Holotype: P.M. 1908-11-13a counter block 1908-11-19a

Locality: Sakamena River Valley in the vicinity of Mount Eliva, southwestern Madagascar.

Horizon: Lower Sakamena Formation.

Biostratigraphy:

Age: Late Permian.

Material: Skeleton complete except for the head.

Referred material:

P.M. 1908-11-8a and counter block 1980-11-20a: Nearly complete skeleton.

P.M. 1908-5-1a, 1908-11-4a, 1908-11-4b, 1908-11-5b, 1908-11-6a, 1908ª11-7a, 1908-11-9, 1908-11-10, 1908-11-12, 1908-11-14, 1908-11-15a, 1908-11-16a, 1908-11-19, 1908-11-20, 1908-5-1, N, R, kyx, y, y/x, OLU: Fragmentary skeletons.
Note: Gastroliths were found.