Washington, January 25 (ANI): In a new international study, scientists have used 3D imaging to shed new light on the way bats echolocate.
The team, led by University of Western Ontario (Western) researchers, used state-of-the-art micro-computed tomography systems to collect detailed 3D scans of the internal anatomy of 26 different bats, representing 11 different evolutionary lineages.
This non-destructive technique allowed researchers to identify a bone that connects the larynx to the bones that surround and support the eardrum in bats.
Some bats use their larynx to generate echolocation (biosonar) signals, allowing them to operate at night; other bats use tongue clicks to achieve the same purpose.
The research team discovered that the connection between the larynx and the ear via the stylohyal bone in the hyoid chain was unique to bats that used laryngeal echolocation.
This observation makes it possible to distinguish bats that produce echolocation signals with their larynx from bats that do not echolocate and those that use tongue clicks.
The discovery adds new information to the ongoing debate about the timing and origin of flight and echolocation in the early evolution of bats.
"This discovery may change the way that researchers interpret previous observations from the fossil record of bats," said Brock Fenton, the Western biologist who led the study.
"These new results give researchers working with fresh or fossil material an independent anatomical characteristic to distinguish laryngeally-echolocating bats from all other bats," he added.
"This work is an important step forward in echolocation research because for years, scientists have been searching for a mechanism that would allow echolocating animals to a have a neural representation of their outgoing biosonar sounds for future comparison with reflected echoes of the sounds, and this anatomical discovery may be that mechanism," said Judith Eger, senior curator of mammalogy at the Royal Ontario Museum.
The small-animal micro-CT used in the study also has implications for clinicians and biophysicists working with animal models to identify and correct hearing impairments in humans.
The results also are important because they emphasize the value of detailed, 3D computerized analysis of extensive existing animal museum collections.
In the future, this type of "virtual dissection" could be used to study the micro-anatomy of many other species of small animals or insects.
The resulting three-dimensional computer display of internal structures is likely to lead to the next generation of "virtual museum", where researchers can study internal anatomy remotely and without dissecting the specimen. (ANI)