Although not obviously noticeable, today the Purus Arch crosses the Amazon River near the mouth of the Purus River. Following the water breach of the arch about 8–10 million years ago, the western (cf. Pebas Mega-wetland) and eastern parts of the present-day Amazon basin became a unified system, which played an important role in the biogeography of many aquatic organisms in the region.[3][4][5]
^Morales L.G. (1957). "A study of the Upper Amazonas and its oil possibilities". Relatório Interno da Petrobras, Depex 822, 22 p.
^Albert, J.S.; Lovejoy, N.R.; Crampton, W.G.R. (2006). "Mioscene tectonism and the separation of cis- and trans-Andean river basins: evidence from Neotropical fishes". Journal of South American Earth Sciences. 21 (1–2): 14–27. doi:10.1016/j.jsames.2005.07.010.