It’s been more than two decades since a Canadian scientist discovered a fossil in Ontario among many others, but finally scientists have noticed that a new species was sitting right under their noses at the Royal Ontario Museum. It’s a new species of ancient marine worm that lived 400 million years ago and had tiny jaws.

The fossil was dug up by Derek Armstrong in 1994 in a remote part of northern Ontario, according to a Christian Science Monitor report. Researchers coming through the collection recently found a species from the class Polychaeta, which are relatives of earthworms, but this one was new.

While most Polychaeta worms had tiny jaws, this one had a pair of jaws that were about 20 times bigger than a normal ancient marine worm. They’ve named the new species Websterprior armstrongi, and it may have been more than three feet long. Their findings were published in the journal Nature.

Lead author Mats Eriksson from Lund University said: “Gigantism in animals is an alluring and ecologically important trait, usually associated with advantages and competitive dominance.

“It is, however, a poorly understood phenomenon among marine worms and has never before been demonstrated in a fossil species.

“The new species demonstrates a unique case of polychaete gigantism in the Palaeozoic, some 400 million years ago.”

Co-author Luke Parry from the University of Bristol’s School of Earth Sciences, added: “It also shows that gigantism in jaw-bearing polychaetes was restricted to one particular evolutionary clade within the Eunicida and has evolved many times in different species.”