Researchers recently announced that they discovered a new species of ghost shark in the Jan. 31 issue of the journal Zootaxa. Ghost sharks–which aren’t actually sharks–are extraordinarily rare sightings. Just a few months ago, in fact, they’d never been filmed alive in their natural habitat. The new species is the second largest ever discovered, and it’s the 50th species of ghost shark so far.

Also known as chimaeras or rat fish, ghost sharks have been around since before the dinosaurs, and are a distant relative of rays and regular sharks. Researchers put the new species into the Hydrolagus genus, which basically means water rabbit. That’s because it’s got an interesting set of teeth that can only be described as buckteeth. So far, there are three other species in the genus, and they all live between South Africa and Antarctica in the southeastern Atlantic and southwestern Indian Oceans.

Fisherman, who accidentally catch ghost sharks on a semi-frequent basis, have been claiming that the new species is just that: a new species. “The scientists and the fishermen in South Africa knew this was not the same species because Hydrolagus africanus [another ghost shark in the same genus] is small, it’s brown, and this one was huge and really dark in color,” Kristin Walovich, a graduate student at the Pacific Shark Research Center, told Live Science. “Just visibly, they were definitely different species.”