A new type of hammerhead shark has been discovered in the northwestern Atlantic Ocean, marine scientists say.
The shark prefers to breed in South Carolina waters
The shark resembles a common species called the scalloped hammerhead but has not yet been classified or named.
US researchers say the animal appears to be rare, breeding only in waters off the South Carolina coast.
They believe the shark is at risk of extinction and conservation efforts are needed to protect females when they are raising their pups.
The shark was discovered by a biology professor at the University of South Carolina.
Dr Joe Quattro became curious about a common coastal shark called the scalloped hammerhead shark while studying coastal fish.
Genetic studies revealed that there was a second "cryptic" species - that is, "genetically distinct" from the scalloped hammerhead.
The shark appears to breed only in waters off South Carolina, although adults swim into waters off Florida and North Carolina.
"If South Carolina's waters are the primary nursery grounds for the cryptic species and females gather here to reproduce, these areas should be conservation priorities," said Dr Quattro.
"Management plans are needed to ensure that these sharks are not adversely impacted so that we can learn more."
Scientists plan to tag the shark so they can understand more about its range.
Ali Hood, director of conservation at the Shark Trust in the UK, said with only 454 recorded species of shark in the wild, it was exciting to discover another one.
"It shows how small areas of coastline are significant to certain species and it is so important to consider shark conservation on an area by area basis," she said.