Genus: Amazonsaurus CARVALHO, AVILLA & SALGADO, 2003
Etymology: For the type-locality which is part of the Brazilian Legal Amazon region, and Greek, sauros, "lizard" for reptile.
= Amargasaurus like CARVALHO & AVILLA, 2002

Species: maranhaensis CARVALHO, AVILLA & SALGADO, 2003
Etymology: In reference to the Brazilian State of Maranhao.

Holotypes: (see below).

Locality: Mata, Itapecuru-Mirim County, Parnaiba Basin, Maranhao State, Brazil.

Horizon: Itapecuru Formation.

Biostratigraphy:

Age: Aptian-Albian Stage, Middle Gallic Subepoch, Upper Early Cretaceous Epoch, Early Cretaceous.

Material:

MN 4558-V, UFRJ-DG 58-R/9: 2 dorsal neural spines.

MN 4559-V, MN s/n°-V: 2 dorsal centra.

UFRJ-DG 58-R/7: Neural spine of anterior caudal vertebra.

MN 4555-V: 1 mid caudal vertebra.

MN 4560-V: 1 mid-posterior caudal vertebra.

MN 4556-V): 1 posterior caudal vertebra.

UFRJ-DG 58-R/10: 1 posterior caudal vertebra.

UFRJ-DG 58-R/2, 58-R/3, 58-R/4, 58-R/5: 4 chevrons.

MN 4564-V: 4 chevrons.

UFRJ-DG 58-R/1: Ilium.

MN s/n°-V: A partial pubis.

MN 4562-V: 3 ribs.