Giant Ancient Crocodile Uncovered in Colombia
The crocodile, described in Paleontology Sept. 15, has a long, narrow snout full of sharp teeth. The fossils were uncovered in the Cerrejón coal mine and reveal a time when Paleocene reptiles dominated the South American environment. Florida Museum of Natural Hist

The remains of a previously undiscovered prehistoric crocodile measuring 20 feet long has been discovered by U.S. researchers in a Columbian coal mine.

The creature, known as Acherontisuchus guajiraensis, is believed to have lived around 60m years ago and is a cousin of the modern-day crocodile, not a direct ancestor.

The excavations at the site were led by Jonathan Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History; and Carlos Jaramillo, a paleobotanist with the Smithsonian Tropical Research Institute.

Early analysis of Acherontisuchus guajiraensis suggest it was one of the few creatures to survive the mass-extinction event which wiped out the dinosaurs.

Alex Hastings, a geological sciences PhD student at the University of Florida, collected the type-specimen for Acherontisuchus - one of a number of prehistoric reptiles found in the area.

"One of the questions about this group was how they were able to survive ... what advantages did they have?" Hastings told FoxNews.com.

"What this new crocodile really contributes to that is that it is the first evidence of a large-bodied member of this group in a freshwater habitat," he said.

Before now, it was thought that only baby crocodiles would spend any appreciable amount of time in freshwater, and that adults would spend most of their time in a saltwater environment.