Canadian paleontologists have uncovered the fossilized remains of Mosura fentoni, an ancient predator dating back 506 million years. The discovery, made by researchers at the Royal Ontario Museum (ROM), has shed light on the anatomy of extinct radiodonts, offering a fascinating glimpse into early marine life from the Cambrian period.
Mosura fentoni, described as resembling a moth, was found in the Raymond Quarry of Yoho National Park in British Columbia. The fossils, collected between 1975 and 2022, revealed the creature’s unique anatomical features, including three eyes, spiny jointed claws, a circular mouth with teeth, and a body with swimming flaps along its sides. These traits place it within the group of radiodonts, which also includes the famous Anomalocaris canadensis, a larger predator that coexisted with Mosura in ancient seas.
One of the most intriguing aspects of Mosura is its segmented abdomen, a feature not previously observed in radiodonts. According to Joe Moysiuk, a curator at the Manitoba Museum, the creature had 16 segments lined with gills, showcasing an evolutionary convergence with modern arthropods such as horseshoe crabs, woodlice, and insects. This suggests that the segmented body structure for respiration may have origins dating back to the Cambrian period.
The discovery also provides detailed insights into Mosura’s internal anatomy, including its nervous system, circulatory system, and digestive tract. Unlike modern animals, Mosura’s heart pumped blood into large internal cavities called lacunae, which supported its complex organ systems. ROM curator Jean-Bernard Caron emphasized the significance of the find, stating that few fossil sites worldwide offer such detailed information on soft internal anatomies, making this discovery a critical piece in understanding the evolution of arthropods.