Scientists are amazed to discover a bat that has been confirmed as a new species to the island chain.

The bat, Synemporion keana, is one of just two bats — the other being the Hawaiian hoary bat — as the only bats native to Hawaii, and is one of only three mammals endemic to Hawaii, with the monk seal being the third, according to an American Museum of Natural History statement.

This bat was smaller than the hoary bat, and showed up about 320,000 years ago. It is believed to have gone extinct about 1,100 years ago.

It’s not some slight difference in the existing genus, but an entirely new creature, scientists believe based on fossils found of the species. Scientists believe its ancestors flew to Hawaii, but they’re not sure where it came from: it could have come from North America, or from Asia, or even from the Pacific islands.

The fossils of Synemporion keana were found in 1981 in a cave on Maui. Decades later, the bat takes on a special new significance in Hawaii’s history.

“The Hawaiian Islands are a long way from anywhere, and as a result, they have a very unique fauna–its native animals apparently got there originally by flying or swimming,” Nancy Simmons, a co-author on the paper and curator-in-charge of the American Museum of Natural History’s Department of Mammalogy, said in the statement. “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.”