At a Glance
- Scientists have discovered a new radiodont species named Mosura fentoni from the Burgess Shale that lived 506 million years ago and had a uniquely segmented abdomen, unlike other early arthropods.
- Mosura had 16 abdominal segments lined with gill-like structures, suggesting specialized adaptations for breathing and movement similar to those found in modern insects and horseshoe crabs.
- This instance of convergent evolution indicates that similar environmental pressures led to the development of comparable features in unrelated species across vast spans of time.
- Exceptionally preserved fossils of Mosura reveal internal anatomy, including its nervous, circulatory, and digestive systems, offering rare insight into early arthropod biology.
- The discovery reinforces the Burgess Shale’s importance in illuminating the Cambrian period and the evolution of complex life on Earth through decades of fossil research.
A discovery from the Burgess Shale, a famous fossil site in Canada, has revealed an ancient predator that adds to our understanding of early arthropods. This creature, named Mosura fentoni after the monster “Mothra” of “Godzilla” fame, was a small, sea-moth-like predator that lived around 506 million years ago during the Cambrian period. The newly discovered species is part of a group known as radiodonts, among the first arthropods to evolve. What sets Mosura apart is its unique body structure, which includes a highly segmented abdomen—a feature not seen in other radiodonts.
The fossilized remains of Mosura show that it had 16 segments in its body, each lined with gill-like structures. This discovery is significant because it suggests that early arthropods, like Mosura, had specialized adaptations for breathing and movement. The abdomen segments in Mosura are similar to those found in modern species like horseshoe crabs and insects, which have multiple segments dedicated to respiration. This is an example of convergent evolution, where different species evolve similar traits due to similar environmental pressures.
The fossils also provide insight into Mosura’s internal anatomy. Remarkably well-preserved, the fossils show detailed features of its nervous, circulatory, and digestive systems. Mosura had an open circulatory system, meaning its blood flowed freely into large body cavities, unlike humans with arteries and veins. This discovery helps scientists better understand the early evolutionary stages of arthropods and their internal structures, which are rarely preserved in such detail.
These findings, published in the journal Royal Society Open Science, not only shed light on Mosura‘s unique anatomy but also highlight the richness of the Burgess Shale site, which continues to provide valuable information about life in the Cambrian period. The research, including fossils collected over several decades, is helping scientists piece together how some of Earth’s earliest complex life forms adapted to their environments. The Mosura discovery is just one example of how the Burgess Shale remains a key resource for understanding the early history of life on Earth.
References
- Royal Ontario Museum. (2025, May 13). Paleontologists discover 506-million-year-old predator. Phys.Org; Royal Ontario Museum. https://phys.org/news/2025-05-paleontologists-million-year-predator.html
- Moysiuk, J., & Caron, J.-B. (2025). Early evolvability in arthropod tagmosis exemplified by a new radiodont from the Burgess Shale. Royal Society Open Science, 12(5), 242122. https://doi.org/10.1098/rsos.242122
