Numerous Species of Crocs Inhabited Ancient Peru

Posted on February 25, 2015

Gnatusuchus pebasensis

Ancient Peru was inhabited by numerous species of Crocs. The crocodiles existed about thirteen million years ago before the Amazon basin had its enormous river. The river formed about 10.5 million years ago.

Scientists found the fossils of at least seven species of crocs in Amazon bone beds. This is the largest number of co-existing crocs ever found in one place during Earth's history. This was due in part to a great abundance of clams and other mollusks for the crocs to eat. The Amazon would have been a massive wetland system with many lakes, swamps and smaller rivers during this time period.

The image above shows a model of the head of Gnatusuchus pebasensis, which scientists believed scooped up clams with its snout. The image below shows a scene of crocs in the Amazonian mega-wetland 13 million years ago. The crocs pictured include Kuttanacaiman iquitosensis (left) and Caiman wannlangstoni (right). Gnatusuchus pebasensis is busy scooping up clams at the bottom of the river. This croc would then crunch the shells with its globular teeth.

Ancient crocs in proto-Amazonian mega-wetland Peru


John Flynn, Frick Curator of Fossil Mammals at the American Museum of Natural History and an author on the paper, says in a statement, "The modern Amazon River basin contains the world's richest biota, but the origins of this extraordinary diversity are really poorly understood. Because it's a vast rain forest today, our exposure to rocks--and therefore, also to the fossils those rocks may preserve--is extremely limited. So anytime you get a special window like these fossilized 'mega-wetland' deposits, with so many new and peculiar species, it can provide novel insights into ancient ecosystems. And what we've found isn't necessarily what you would expect."

A research paper on the extinct caimans can be found here in the journal, Proceedings of the Royal Society B.

Images: Aldo Benites-Palomino (top)/ Javier Herbozo (second)