No one had spotted the world’s smallest known snake for nearly two decades. Some scientists worried that maybe the Barbados threadsnake had become extinct.

I was making a joke and in my head I said, ‘I smell a threadsnake,'” Justin Springer, Caribbean program officer for the NGO Re:wild, recalled. “I just had a feeling, but I couldn’t be sure because we turned over a lot of rocks before that and we saw nothing.

The Barbados threadsnake was among 4,800 species of plants, animals and fungi once believed to be lost to science.