Friday, August 12, 2016

Echovenator sandersi: a Toothed Whale Fossil Shows High Frequency Echo Location Hunting Evolved 10 Million Years Earlier Than Previously Thought

A newly-named fossil whale species had superior high-frequency hearing ability, helped in part by the unique shape of inner ear features that have given scientists new clues about the evolution of this specialized sense.

In a study published August 4 in Current Biology, researchers from New York Institute of Technology and colleagues from the National Museum of Natural History in France describe a new species of whale, Echovenator sandersi ("Echo Hunter"), an ancient relative of the modern dolphin, and its ability to hear frequencies well above the range of hearing in humans.

The research pushes the origin of high frequency hearing in whales farther back in time -- about 10-million years than previous studies have indicated.

"Previous studies have looked at hearing in whales but our study incorporates data from an animal with a very complete skull," says Morgan Churchill, a postdoctoral fellow at NYIT College of Osteopathic Medicine and the paper's lead author. "The data we gathered enabled us to conclude that it could hear at very high frequencies, and we can also say with a great degree of certainty where it fits in the tree of life for whales."

"This was a small, toothed whale that probably used its remarkable sense of hearing to find and pursue fish with echoes only," says Associate Professor Jonathan Geisler, a study co-author. "This would allow it to hunt at night, but more importantly, it could hunt at great depths in darkness, or in very sediment-choked environments."

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