Gigantic Extinct Worm With Impressively Large Jaws Discovered In Canada


Catch ‘em! An artistic reconstruction of W. armstrongi hunting prey. Credit: James Ormiston

A long primordial worm with massive jaws has been discovered in Ontario, Canada, providing a snapshot of the sea some 400 million years ago. The worm, called Websteroprion armstrongi, reached a jaw-dropping 2 meters (6.6 feet) in length, proving itself an undersea creature not to be messed with.

The raptorial worm likely feasted on fish, snatching them with their jaws and dragging them into underwater burrows. This, although still speculative, is similar to its closest living relative – the giant eunicid species, dubbed “Bobbit worms”.


The ancient fossil was recently rediscovered at the Royal Ontario Museum, but was originally found in the sediment of the Hudson Bay Basin in Ontario, Canada. The new findings are published in Scientific Reports.

Bobbit worms (Eunice aphroditois) are ambush predators that bury their long bodies in the ocean floor, launching at prey with sharp teeth and great speed. SARAWUT KUNDEJ /Shutterstock

This extinct species is by no means the longest worm. That lovely award belongs to the bootlace worm (Lineus longissimus), which typically measures 5-15 meters (16-50 feet) in length, but was once found at over 55 meters (180 feet).

However, W. armstrongi does receive one award: It possesses the largest jaw in the fossil record of polychaetes – a diverse group of segmented worms – at over 1 centimeter in length. While this doesn’t exactly sound record-breaking, these creatures usually have jaws only a few millimeters in size. 


“Gigantism in animals is an alluring and ecologically important trait, usually associated with advantages and competitive dominance,” said lead author Mats Eriksson of Lund University in a statement. "It is, however, a poorly understood phenomenon among marine worms and has never before been demonstrated in a fossil species.” 

Despite the primarily soft anatomy of polychaetes, which results in low preservation potential, their fossil record extends to the beginning of the Palaeozoic. Multiple specimens of W. armstrongi were also found, suggesting it was a common species at this location of the Kwataboahegan Formation million of years ago.

A 3D reconstruction of various parts of the jaw of W. armstrongi. Credit: Luke Parry 

Jaw-dropping imprints. Credit: Luke Parry


The creature has been named Websteroprion armstrongi in honor of Derek K. Armstrong, who collected the first specimens in the field, and Alex Webster – a “giant” of a bass player from the death metal band Cannibal Corpse.

As it turns out, sometimes scouring the depths of a museum can garner a gem of a specimen overlooked by its previous discoverers.

Check out a video of a Bobbit worm in action below.



Hidden Killer: The Bobbit Worm from Jungles in Paris on Vimeo.


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