Scientists unearth most primitive bat ever found

By Will Dunham

WASHINGTON (Reuters) - The most primitive bat ever found fluttered around about 52 million years ago, but lacked a key feature seen in most bats -- the ability to echolocate, hunting and navigating using a kind of sonar.

A team of scientists announced the discovery on Wednesday of a medium-sized ancient bat called Onychonycteris finneyi that possessed fully developed wings and was completely capable of flying. But they said that based on the evidence from its skeleton it lacked the ability to echolocate.

Kevin Seymour of the Royal Ontario Museum in Canada, one of the scientists who describe it in the journal Nature, said this bat appears to settle a long-standing debate of which came first in bats -- echolocation or flight. The answer is flight.

"It is like this is sort of half way to being a modern bat. It's the most primitive bat that we know. It could clearly fly. But it could not echolocate. The evidence from the skull and throat region shows us none of the features that echolocating bats have," Seymour said in a telephone interview.

Bats are the second most common type of mammal living today, constituting a fifth of all mammal species. Only rodents, which make up half of mammals, are more plentiful.

Bats also are an ancient form of mammals, and scientists have struggled to understand their early evolutionary history. Onychonycteris, unearthed in 2003 in southwestern Wyoming, appears to be filling in some important gaps.

"MISSING LINK"

"It's clearly a bat, but unlike any previously known," Nancy Simmons of the American Museum of Natural History in New York said in a statement. "In many respects it is a missing link between bats and their nonflying ancestors."