A species of nocturnal snake once thought to be either extinct or entirely nonexistent has been "rediscovered" by Smithsonian scientists, a new field study reported.

The study is published in PLOS ONE and details the circumstances around the discovery and rediscovery of Hypsiglena ochrorhyncha unaocularus - the Clarion nightsnake.

According to the study, renowned naturalist William Beebe first encountered this mysterious snake in 1936 during a three month expedition, taking a yacht from San Diego California out to Isla Clarión in the Revillagigedo Archipelago.

According to the naturalist's journals, it was there that he encountered the Calrion nightnsake - a subspecies of nightsnakes that had a very distinct habitat and markings. However, in field studies on the island years later, the nightsnake was never found, suggesting that the lone snake sample was either now extinct, or simply an observational error.

But, in an attempt to verify Bebee's work, National Museum of Natural History researcher Daniel Mulcahy launched several DNA tests of the original Bebee specimen. While testing did indicate the snake had some ties to other nightsnakes, it remained inconclusive as to whether the Clarión specimen was its own species or not.

Then, working with Juan Martínez-Gómez, an expert on the Revillagigedo Islands, Mulcahy retraced Bebee's steps, eventually finding 11 snakes amid a rock habitat near the waters of Sulphur Bay that matched Bebee's description. The researchers wrote that they suspect that the species was formally declared extinct and remained absent in field studies because their habitat is extremely remote and difficult to gain access to.

DNA testing on the snakes verified that they are indeed their own full species - genetically distinct from other snakes located on the mainland of Mexico.

"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," Mulcahy said in a Smithsonian press release. "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."

The study detailing this discovery was published in PLOS ONE on May 16.