“The extinction marked an ecological turning point for the pelagic marine vertebrates,” said professor Richard Norris from Scripps Institution of Oceanography at University of California, San Diego, according to Gulf News.
Norris and graduate student Elizabeth Sibert’s research finding appeared in the journal Proceedings of the National Academy of Sciences.
Ray-finned fish, defined by their bony fins, are the world’s most diverse vertebrates and account for 99 percent of modern fish species. There are 30,000 ray-finned fish species in the oceans. Virtually all of the common fish — from tropical fish in an aquarium to tuna in the ocean — are ray-finned fish.
By examining fossilized fish teeth, the scientists discovered the population of ray-finned fish did not begin to explode until after the dinosaur era.
“Before the extinction of dinosaurs, ray-finned fishes existed in a state of relative ecological insignificance just like mammals on land,” Sibert said to Gulf News.
Sibert and Norris noticed how quickly fish multiplied after the extinction and believe that other marine groups had also become extinct. Fish were then freed from predation or competition.
The researchers note that mammals also had become more abundant after the dinosaurs were gone. “Ray-finned fishes have the same kind of story.”
