First thought to be crossed out in the scientific records indefinitely, a very elusive and mysterious species of snake was once more sighted in the same remote island 700 kilometers off Mexico where it was first discovered 80 years ago.

It was in 1936 when natural scientist William Beebe first discovered the nocturnal serpent slithering alone amid the volcanic rocks of Isla Clarión, the second largest and most remote island in the four islets of Revillagigedo Islands. It was difficult to spot since the snakes with its brown and black colorings blended well with its environment.

Beebe gave it the name Hypsiglena ochrorhyncha unaocularus, which is now more commonly known as Clarion nightsnake, and was tagged and stashed away in the anthology of American Museum of Natural History's specimens. Since then, no other sighting of the nightsnake was ever reported, which then stirred a series of questioning in the scientific community about the find's legitimacy.

The access to the island made it even harder to prove the snake's existence, since biologists could only conduct their studies if they have a military escort. The snakes themselves are naturally hard to pin down, with a length of 18 inches long and streaks of colors that allows them to ingeniously hide themselves in their natural habitat.

Eight decades later, the case of the lost Clarion nightsnake may now be considered solved thanks to the efforts of a team led by Daniel Mulcahy, a researcher at the National Museum of Natural History, and Juan Martínez-Gómez, who is knowledgeable about the islands where these snakes thrive. Their findings can be found in the journal [pdf] PLOS One.

"The rediscovery of the Clarion nightsnake is an incredible story of how scientists rely on historical data and museum collections to solve modern-day mysteries about biodiversity in the world we live in," Mulchay said.

At first, Mulcahy studied the same specimen discovered by Beebe. However, he found the markings of the snake so striking that it encouraged Mulcahy to search for the Clarion night snakes again.

In 2013, Mulcahy and Martínez-Gómez, together with a team from the Instituto de Ecología in Mexico, set forth to the islands in hopes of rediscovering the lost Clarion nightsnakes. As luck would have it, the entire team found 11 snakes that had the same characteristics as the one found by Beebe in the same island.

After a string of laboratory tests at the Smithsonian's Laboratories of Analytical Biology, Mulcahy was able to validate that these snakes are, after all, existing and true. It has now been given the name Hypsiglena unaocualrus.

"Proper identification is the first step toward conserving this snake, and we plan to continue monitoring this species to learn more about the role it plays in the delicate Clarion Island ecosystem," Mulchay remarked.