Prehistoric, shark-like fish could help rewrite aquatic predator timeline

The extinct species -- known as Birgeria americana -- measured nearly six feet long and swam in the sea that covered what is current day Nevada some 252 million years ago.

Chad Young | Aug 09, 2017

A team of Swiss and U.S. researchers working in northeastern Nevada have discovered an ancient, shark-like fish that could help shed light on aquatic predator evolution, recentresearchpublished in the Journal of Paleontology reports.

The extinct species -- known as Birgeria americana -- measured nearly six feet long and swam in the sea that covered what is current day Nevada some 252 million years ago.

What makes the prehistoric fish so interesting is that is had a set of elongated jaws equipped with three parallel rows of sharp teeth on the outside and numerous smaller teeth on the inside. That unique structure suggests the fish chomped down on its prey before swallowing it whole. Such behavior mimics the eating habits of modern day sharks and could help shed new light on fish evolution,Tech Timesreports.

"The surprising find from Elko County in northeastern Nevada is one of the most completely preserved vertebrate remains from this time period ever discovered in the United States," explained lead author Carlo Romano, a researcher at the University of Zurich, in a statement.

B. americana came about shortly after a massive extinction event that killed off roughly 90 percent of marine animals on Earth. While previous research suggests that the first predators on top of the food chain did not show up until 247 to 235 million years ago, this new finding rewrites that timeline.

Not only does the new fossil predate the predatory Ichthyosaur by over 30 million years, but it also reveals that large fish were able to survive in water previously thought to be too warm to support life. In this way, the bones could also help shed light on the way large predators evolved following the mass extinction that took place at the end of the Triassic period.

"The vertebrates from Nevada show that previous interpretations of past biotic crises and associated global changes were too simplistic," added Romano.

The team plans to follow up on their findings to see what other species the new fossils can help them understand.

bottom ad