The research team that studied the fossils described them as marine animals that lived during the early part of a period that followed the Cambrian, known as the Ordovician.
Professor Derek Briggs from Yale University in New Haven, US, who was an author of the study, told BBC News that the discovery provided “a much more complete record of early marine life than we’ve ever had before”.
The creatures, he explained, closely matched those found in the Burgess Shale of British Columbia, a locality in Yoho National Park, which is famous for yielding rare fossils of soft-bodied marine creatures from the Middle Cambrian period.
“There was an anomaly in the fossil record,” said Dr Peter Van Roy, the lead researcher on the study, who is also based at Yale University. “Most of these animals just seemed to disappear at the end of the Middle Cambrian.”
The transition between the Cambrian and the Ordovician periods is crucial in evolutionary history.