A bat native to Hawaii has recently been recognized for the first time, making it the second mammal known to have evolved on the island chain. However, that winged animal is now extinct.

Synemporion keana lived together with the hoary bat for thousands of years before the arrival of the first humans on the islands, researchers report. Soon after, people arrived in Hawaii, and the species disappeared.

"Besides the animals that humans have introduced to the islands, like rats and pigs, the only mammals that we've known to be native to Hawaii are a monk seal, which is primarily aquatic, and the hoary bat. So finding that there actually was a different bat - a second native land mammal for the islands - living there for such a long period of time was quite a surprise," said Nancy Simmons of the Department of Mammalogy at the American Museum of Natural History.

The remains of the now-extinct bat were uncovered in 1981 inside a lava tube on the island of Maui. Later, specimens of the ancient animals were found on the big island of Hawaii, Oahu, Molokai and Kauai.

Mammalogist Alan Ziegler studied the remains for decades, until his death in 2003, attempting to place the species in the family tree of animals. Following the loss of Ziegler, the research was carried out by Simmons and Francis Howarth, an entomologist who found the original specimen.

They found out that the creatures are a form of evening bat, or vesper, unlike any other species.

Researchers studying the extinct animal are uncertain where the ancestors of Synemporion keana came from prior to the species first landing on the island chain.

This species appeared to have evolved about 320,000 years ago, later going extinct 1,100 years past. Its disappearance may have been linked to invasive species that arrived along with the first human settlers. Many native forests and insects on the island also suffered setbacks as people arrived on the Pacific Island chain.

Future research may compare the Synemporion keana to other species of bats through the use of DNA analysis.

Discovery and analysis of the newly recognized species of extinct bat were profiled in the journal American Museum Novitates.