BEACON TRANSCRIPT – The scientific community is amazed after the discovery of dolphin fossils in a drainage ditch in South Carolina. The fossils bring a fresh perspective on the evolution of echolocation and ultrasonic hearing. Prehistoric dolphins and modern day dolphins have something in common: they can hunt and navigate using ultrasounds.
A team of scientists analyzed fossils from a newly identified dolphin species called Echovenator sandersi which lived in shallow sea waters some twenty-seven million years ago. What they found was arguably the best-preserved skeleton ears of an ancient mammal.
After doing computer tomographic scans of the ear and comparing it with other dolphin species, the Echovenator’s ear was found to have many characteristics in common with modern mammals. One of these characteristics is the ability to hear and emit ultrasonic frequencies, which cannot be heard by humans.
The biological sonar, sometimes called echolocation is used by whales and dolphins to give out high-frequency sounds that return in the form of an echo. This way, they can identify an object’s location to a very precise degree.
Echolocation was an important evolutionary trait for whales and dolphins. Before developing biological sonars, these mammals used to hunt their prey by using just their sight.
Echolocation allows dolphins to hunt for fish and squid in unclear waters and survive at great depths.
This is one of the most complex evolutionary adaptations in mammals. Out of the six thousand mammal species which are alive today, only bats, whales, dolphins and a couple of insectivores use biological sonars as a way of navigating and preying in their environment.
In the early days of E.Sandersi, about twenty-seven million years ago, it looked much like today’s dolphins. However, the research has also concluded that the sonar system did not function as well as it does in modern-day dolphins.
Scientists are amazed at how early this intriguing hearing system evolved. On an evolutionary scale, it happened very quickly and it does raise some important questions. The scientific community wants to do further research is required to clear the mystery surrounding the evolutionary path of whales and dolphins.
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