Scientists believe they have discovered a new species of hammerhead shark.

While the “bonnethead,” a small species of hammerhead found in the U.S., the Bahamas, the Caribbean and Latin America, had been considered abundant, after a recent DNA sequencing of bonnethead sharks in Belize, they were shocked to find what is likely an entirely different species.

What that means, though, is that scientists will have to reassess each of their extinction vulnerabilities.

“Now we have to define the range of each of these species individually and assess them independently against where the potential threats are,” said Florida International University marine scientist Demian Chapman, who is the lead researcher of the team making the discovery.

So what did the scientists discover about the species?

While it can be difficult to determine when one species becomes two, a trait that defines this process is the end of interbreeding between the two groups, the scientists said.

The DNA analysis conducted by Andrew Fields from Stony Brook University enabled the team in Belize to estimate bonnethead sharks around the nation stopped interbreeding with those from Mexico, the United States and the Bahamas several million years ago. Over time, genetic differences accumulated between the two groups. While their appearances haven’t changed, their DNA definitely has.

The data that led to the finding was obtained in part during a 2016 shark tagging expedition.

Bonnetheads are commercially fished in the United States, throughout the Caribbean and in South America; only the U.S. has strong management measures in place for the species.

— Caribbean Journal staff