In a paper published in the Zoological Journal of the Linnean Society, scientists reveal that a beaver like animal, called Kimbetopsalis simmonsae, replaced the dinosaurs and was one of the largest animals in the post apocalyptic era, the Washington Post reports.

After the meteorite-induced apocalypse, "all this ecological space became available and the mammals went a bit nuts," said Sarah Shelley, a paleontologist at the University of Edinburgh and a co-author on the paper.

Kimbetopsalis was recently discovered from a few teeth and a fragment of skull discovered during an archaeological dig in a remote New Mexico desert. The fossils were uncovered by Carissa Raymond, a sophomore at the University of Nebraska.

From those fossil fragments, Shelley and her colleagues gained a rough understanding of how the ancient mammal looked and lived.

Scientists believe that Kimbetopsalis grew from tiny proportions to the size of a very large beaver over the course of just 500,000 years. Paleontologists say it had a beaver's broad face and chunky frame as well, but lacked a paddle-like tail.

Kimbetopsalis is one of the longest-living groups of mammal in history. It survived for 160 million years.

 "The history of life hinges on moments that can reset the course of evolution," Stephen Brusatte, a professor of vertebrate paleontology at the University of Edinburgh and another co-author on the paper, wrote in an essay for the conversation.