Washington, August 8 (ANI): A new fossil-bat discovery has revealed that a walking bat in New Zealand took its marching orders from a 20-mln-yr-old ancestor, which upends a theory that the lesser short-tailed bat evolved its walking preference independently.
Since the bat's native habitat lacks predators, researchers reasoned that-much like flightless birds on isolated islands-the bat had adapted to its safer surroundings in part by walking.
But, according to a report in National Geographic News, the discovery of fossils of a now extinct walking bat in northwestern Queensland, Australia, suggests that the modern-day bats descended from 20-million-year-old Australian relatives.
"We were amazed to find they were virtually identical to the bats in New Zealand today," said study leader Sue Hand, a paleontologist at the University of New South Wales in Sydney.
The fossil bat had a similar groove in its elbow as its modern counterpart.
This supports a specialized muscular system that allows bats to launch from the ground, where they spend about 40 percent of their time.
Unlike their modern relatives, the ancient bats had plenty of predators, including marsupial lions and carnivorous kangaroos.
But, the quick little bats, measuring up to three inches (eight centimeters) long, would have easily escaped capture.
"They're very agile on the ground, quick to fly, and reasonably aggressive," Hand said.
The New Zealand bats "were in a perfectly good position to exploit a predator-free niche," she added.
Gaining the ability to walk and burrow opened up new food opportunities for the mammals, she explained.
"Being on the ground allowed it to have an incredibly broad diet-an advantage when things became colder," said Hand.
About 15 million years ago, when Australia underwent a climatic shift that made the continent cooler and drier, the Australian walking bats seemed to have died off.
Of the 1,100 known present-day bat species, the lesser short-tailed bat and the American common vampire bat are the only two known to walk on the ground. (ANI)