A team of scientists from South Carolina has discovered a fossilized ear of a prehistoric animal that holds the answer on the origins of whales' ultrasonic hearing.

According to the study published in the journal Current Biology, the fossil is from a newly identified dolphin called Echovenator sandersi found in a drainage ditch in South Carolina. Using CT scans, the scientists compared the animal's ear to other whales and found out that showed similar characteristics with present-day whales that has ultrasonic hearing.

Morgan Churchill, lead author of the study, explained that the animal's skull features are associated with echolation, which is the ability to process high-frequency soundwaves and then bounce them off as echoes. Particularly, the inner ear of the animal is very similar to whales in modern times.

"Echovenator already shows skull features associated with echolocation, although it perhaps couldn't have processed signals from echolocation as well as modern dolphins," Churchill said.

Currently, echolation is present in modern-day dolphins, sperm whales and orcas. These animals communicate via echoes in order to navigate and hunt in the ocean, (e) Science News reports.

"Echolocation is probably one of the most remarkable and unique adaptations within mammals. Out of 6,000 mammal species alive today, only bats and toothed whales, along with a very small number of small insectivores, use echolocation as a major way of navigating their environment," Morgan Churchill, lead author of the study, told Reuters.

Echovenator sandersi existed 27 million years ago and lived in shallow, warm seas. It's also relatively small compared to other ancient whales at only six feet long. The name "echovenator" means "echo hunter," describing the marine animal's ability to produce echoes.

Apart from the Echovenator, the team reveals that they are also studying other whale fossiils to unlock more secrets regarding the evolution of these animals.