The Clarion nightsnake is hard to spot, so hard to spot that for decades, the only sighting of the species native to one of Mexico's Revillagigedo Islands—the original sighting—was assumed to be a mistake. A joint US-Mexico team, however, managed to rediscover the species found by American naturalist William Beebe in 1936 by using his original field notes to retrace his steps and search for the nocturnal snake, which blends in with the island's rock formations, the AP reports. The expedition found 11 of the snakes, and DNA tests confirmed that the Clarion Island snake is a unique species, reports the BBC.
The snake is related to snakes found on part of the Mexican coast more than 500 miles away, and researchers believe its ancestors may have arrived on a tree trunk washed out to sea long ago. Beebe returned from a visit to the island, located 400-plus miles off Mexico's Pacific coast, nearly 80 years ago with a snake preserved in a jar, but his sample had long been considered a labeling error and his find was largely struck from taxonomic registries. The National Museum of Natural History praised the team's work, describing the snake as the "only species ever to be discarded due to a presumed locality error." The rediscovery "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," the museum said in a statement.