The newly-found ancient fish, "Laccognathus embryi", is a 1.8-meter-long predator, which was "waiting to lunge out to grab whatever was in front of it," said study co-author Ted Daeschler, a vertebrate zoologist at the Academy of Natural Sciences in Philadelphia, the U.S..

　　It had a jaw filled with sharp teeth that were 1.5 inches long, the Journal of Vertebrate Paleontology described.

　　The fish lived in the Devonian period, 415 to 360 million years ago, which "was a fish-eats-fish kind of world," Daeschler said. "There was a real arms race going. If you didn't have good armor on your body, you were very vulnerable."

　　"It's not just finding the animal - it's also placing the animal in its evolutionary crucible," Daeschler added.

　　Its closest living relative is the lungfish which can survive in the drought, scientists said.

　　Scientists hope the finding can help in their study on the revolution of fishes as well as other species.