Featured Image Credit: Marianne Collins/Royal Ontario Museum via AP
By Jessica Kittel
I would not have wanted to be a small crustacean 508 million years ago. If I were, then I would have had to worry about a particularly menacing looking flat worm that roamed the deep sea. Those poor ancient crustaceans probably had nightmares about running into this worm and its’ 50 sharp spines in a dark alleyway at night.
Recently identified by Yale University scientists, this worm, named Capinatator praetermissus, was four inches of pure terror. Okay, probably not pure terror, but at least a little terror. According to Live Science, the worm’s long, inward-curving spines are thought to have been used to catch small creatures swimming along in the water, including small shrimp-like crustaceans and various other marine larvae.
The researchers at Yale University (in coordination with the Royal Ontario Museum) used a collection of 50 fossil specimens, all from Burgess Shale in British Columbia, to identify this new genus and species. The Burgess Shale deposit, located in the Canadian Rocky Mountains, is known as a hotspot for finding fossils left over from the Cambrian period, a period that spanned 543 to 490 million years ago. While it is relatively common to come across a fossil containing a chaetognath spine, finding fossilized remains of soft tissues is much more rare, albeit exceedingly valuable when attempting to identify a new species.
Yale News reported that this newly named worm is actually a chaetognath, a type of bristly jawed, carnivorous marine worm, also known as arrowworms. This new worm is actually one of the largest types of chaetognath worms discovered to date. Its’ scientific name roughly translates to mean “overlooked grasping swimmer.”
As can be seen in the video below, the scientists believe that this worm swam by undulating its body. When they found their dinner, they would have extended their spines (25 on each side of their head) and then closed them over their prey. The number of spines on C. praetermissus is notable due to the fact that today’s chaetognaths have roughly half the number of spines seen on their Cambrian ancestors.
While they might have been fearsome to behold, these ancient chaetognaths were undoubtedly an important component of Cambrian marine ecosystems.