Paleontologists unveil 506-million-year-old sea predator in Canada

In a remarkable discovery, Canadian paleontologists have unveiled Mosura fentoni, an ancient predator that thrived during the Cambrian period, approximately 506 million years ago, in what is now British Columbia. The announcement came from the Royal Ontario Museum, which detailed the findings in a recent press release. Over the decades, particularly between 1975 and 2022, extensive excavations at Raymond Quarry in Yoho National Park have yielded numerous well-preserved fossils which contribute to our understanding of early arthropods. Mosura fentoni is notable for its size, approximately that of a human index finger, and for its unique anatomical features, including three eyes, spiny jointed claws, and a circular mouth lined with teeth. The creature's body exhibited swimming flaps along its sides, placing it in the extinct group known as radiodonts. This group also included the well-known predator Anomalocaris canadensis, highlighting the ecological complexity of early marine environments. One of the most intriguing aspects of Mosura's anatomy is the segmented abdomen, which consists of 16 segments lined with gills—an attribute previously unidentified within radiodonts and suggesting evolutionary parallels to modern species like horseshoe crabs and woodlice. Joe Moysiuk, a curator at the Manitoba Museum, emphasized this evolutionary convergence, illuminating how ancient species can share anatomical similarities with today's organisms. This remarkable preservation also provides insight into the creature’s respiratory system, which used lacunae for circulation instead of the arteries and veins seen in modern animals. Additionally, the fossils reveal intricate details of Mosura’s internal anatomy, including its nervous system. Jean-Bernard Caron, a curator at the Royal Ontario Museum, remarked on the exceptional quality of the fossil site, which enables scientists to examine aspects such as nerve bundles tied to Mosura's visual capabilities. These discoveries are significant not just for understanding Mosura, but also for providing broader insights into the evolution of arthropods and the dynamics of ancient ecosystems, marking a crucial point in the study of early life forms on Earth.