Canadian researchers studying 450-million-year-old fossils near Quebec City have identified a new species of basal-medusozoan: Paleocanna tentaculum, a soft-bodied, tube-shaped polyp with a ring of tentacles.
Closely related to modern jellyfish, the species was identified from fossils discovered about 50 kilometres northeast of Quebec's capital. It's a rare find: only a few other species in its subphylum have ever been described in the fossil record.
It's likely the fossils were preserved during a sudden burial event on the seafloor during the Paleozoic era, when fine mud quickly covered the animals and protected their remains from scavengers and disturbance.
The find by researchers at Université de Montréal and McGill University is detailed in a study published in February in the Journal of Paleontology.
“Because several (polyps) are aligned in the same direction, we think they were buried in place or were not transported far before being buried,” said the study's lead author, Greta Ramirez-Guerrero, a PhD candidate at UdeM supervised by biology professor Christopher B. Cameron.
“This rapid burial, combined with low-oxygen conditions in the surrounding environment, slowed decay and helped preserve the animals before the sediment turned to rock," said Ramirez-Guerrero.
Soft-bodied organisms do not preserve as well as hard-bodied organisms, usually making any soft-bodied fossil more valuable to understanding the history of life, said co-author Louis-Philippe Bateman, a graduate student in biology at McGill.
The discovery also highlights Quebec’s significant fossil record, he added.
“I've often caught myself saying that we have a less glamorous fossil record than places like British Columbia or Alberta,” Bateman explained. “Discoveries like this one show that many things have yet to be discovered and described here.”
