Astudycarried out byProfessor Jonathan Geislerat the New York Institute of Technology College of Osteopathic Medicine has provided evidence for a primitive mannikin of the biological sonar , experience as echo sounding , which existed in a congenator of present daylight odontocetes ( toothed whale and dolphin ) that lived around 28 million year ago . The subject field was publish yesterday in Nature .
echo sounding involve the emanation of calls that produce sound wave , which travel into the environment and eventually bounce off objects . The animal then listens to echoes that reappearance . This allows the animal to detect how far out a particular target is by the length of prison term it assume for the echo to return . The beast can also determine the placement , size of it and front of objects . This allows the animal to pilot through gloomy environments where vision is poor , like muddy water supply or dark cave . Echolocation is used by numerous beast other than odontocetes , include bats , shuttle and shrews . Echolocation is usually at such a high lurch that it can not be discover by humans .
Discoveries of complex adaptations are always exciting , and it is often found that they evolve in a step - sassy , gradual fashion . Through the habit of fogey records , we can observe small changes over prison term which top to particular feature article that conform the organism to its changing surround . Odontocetes are unique in their mechanism of echo sounding ; they bring forth high - absolute frequency vocalisations in a constricted surface area of nasal passage just beneath the blowhole shout out the phonic lips . This vox is then modulated by a large fatso organ refer the melon vine . Until now , the origins of echo sounding remained a mystery .
The researcher discovered an odontocete fossil in South Carolina , which was from the Oligocene , part of the Paleogene period that extends from around 40 to 23 million years ago . The fossil , Cotylocara macei , presented several features which suggested it was capable of echolocation . This include a dense and downturned rostrum , and a cavity at the top of its head which could potentially have served to store aviation and reflect sound . They also discovered a bowl - like area of bone near the nasal openings which could have served to reflect sound and thus ameliorate echolocation in this brute .
