News Bite: Crazy croc diversity in the ancient Amazon!

In a study published in the Proceedings of the Royal Society B, Rodolfo Salas-Gismondi and other paleontontologists described the crocodiles from a gigantic wetland that predated the Amazon. Ten million years ago there was the giant Purussarus, the duck-billed Mourasuchus, the tube-snouted gharial-like croc, a coyote-like croc similar to Paleosuchus, and three new crocs with […]

In a study published in the Proceedings of the Royal Society B, Rodolfo Salas-Gismondi and other paleontontologists described the crocodiles from a gigantic wetland that predated the Amazon. Ten million years ago there was the giant Purussarus, the duck-billed Mourasuchus, the tube-snouted gharial-like croc, a coyote-like croc similar to Paleosuchus, and three new crocs with broad teeth perfect for crushing shells: Kuttanacaiman, Caiman wannlangstoni, and Gnatusuchus pebasensuis. This is the largest number of croc species living in the same place at the same time that the Earth has ever known. How did they find room for each other in the ecosystem? These new animals from Peru shed light on the South American croc ecosystem before the Amazon River started to flow and tell us we have a lot to learn about the ways crocs can make a living.

The crocodiles from the Pebas Formation were a diverse bunch. The fossil new species are shown on the left drawn by Javier Herbozo, the giant Purussaurus was drawn by Nobu Tamura, Mourasuchus-like Stomatosuchus (they look similar, but are distantly related) by Dmitry Bogdanov.

Drawing of the new croc species from the Pebas Formation in northeastern Peru by Javier Herbozo. All three are closely related to caimans, a group of crocodilians closely related to alligators. Gnatusuchus has blunted teeth that would have made it a formidable shellfish eater.

Citation:

Rudolfo Salas-Gismondi, John J. Flynn, Patrice Baby, Julia V. Tejada-Lara, Frank P. Wesselingh, Pierre-Olivier Antoine. 2015. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands. Proceedings of the Royal Society B.