儘管巴西已發現許多恐龍化石,亞馬遜龍是首種在亞馬遜盆地發現的恐龍。其屬名是以巴西亞馬遜地區為名。亞馬遜龍目前只有一個種,學名是馬拉尼昂亞馬遜龍(A. maranhensis),種名是以巴西的馬臘尼昂州而來。在2003年,巴西古生物學家Ismar de Souza Carvalho及Leonardo dos Santos Avilla、與他們的阿根廷同僚利安納度·薩爾加多(Leonardo Salgado)將這些化石敘述、命名的。
^Salgado, L., Garrido, A., Cocca, S.E., & Cocca, J.R. 2004. Lower Cretaceous rebbachisaurid sauropods from Cerro Aguada del León (Lohan Cura Formation), Neuquén Province, northwestern Patagonia, Argentina. Journal of Vertebrate Paleontology 24(4): 903-912.
^Carvalho, I.S., Avilla, L.S., & Salgado, L. 2003. Amazonsaurus maranhensis gen. et sp. nov. (Sauropoda, Diplodocoidea) from the Lower Cretaceous (Aptian–Albian) of Brazil. Cretaceous Research. 24: 697-713.
^Novas, F.E., de Valais, S., Vickers-Rich, P., & Rich, T.H. 2005. A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids. Naturwissenschaften. 92: 226–230.