Fossilized teeth allowed researchers too peer into bats' ancient lineage.
Madagascar sucker-footed bats cannot be found outside of their "island home," but new research suggests they evolved in Africa and later moved to South America, a Duke University news release reported.
The team found the bat family was about 36 million years older than they previously believed.
"We've assumed for a long time that they were an ancient lineage based on DNA sequence studies that have placed them close to very old groups in the bat family tree," Nancy Simmons, co-author and curator-in-charge of the American Museum of Natural History's Mammalogy Department said in the news release.
The researchers believe sucker-footed bats (which developed stick foot pads to help them cling to slippery surfaces once existed outside of their Madagascar habitat.
There are currently two species of sucker-footed bats in Madagascar, Myzopoda aurita and M. schliemanni. Unlike most bats that hang upside down, the sucker-footed bat roosts with its head up in traveler's palm leaves. In the past researchers thought the bats held themselves in place by suction, but new research suggests they actually rely on wet adhesion (the method used by tree frogs).
Researchers excavated the Fayum Depression in Egypt's Western Desert where they found ancient human relics as well as ancient bat teeth and jawbones.
The team found remnants of two species, Phasmatonycteris phiomensis and P. butleri; the fossils dated back to 30 and 37 million years ago when Northern Africa was much more tropical and diverse.
"The habitat was probably fairly forested, and there was likely a proto-Nile River, a big river that led into the ancient Tethys Ocean," Gregg Gunnell, director of the Duke University Lemur Center's Division of Fossil Primates.
Researchers are unsure if these ancient species had already developed sucker feet, but the researcher shows the Madagascar bats are part of a long-lived lineage.
Most of South America's bats are believed to belong to the superfamily Noctilionoidea.
"We think that the superfamily originated in Africa and moved eastward as Gondwana was coming apart," Gunnell said. "These bats migrated to Australia, then actually went through Antarctica and up into South America using an ice-free corridor that connected the three continents until about 26 million years ago."
"Now, we can unambiguously link them through Africa," Simmons said.
