Researchers have made an extraordinary discovery that has significantly expanded our understanding of the evolutionary history of mollusks, one of the largest and most diverse groups of animals on Earth. By examining two 430 million-year-old fossils, named Punk and Emo, the team has revealed that ancient mollusks were far more complex and adaptable than previously thought. These exceptional fossils, unearthed from the Silurian period in Herefordshire, challenge long-standing assumptions about the early origins of mollusks, particularly those belonging to the Aculifera group, which includes chitons and worm-like mollusks.
Traditionally, scientists have regarded early mollusks from the Aculifera group as relatively simple and primitive creatures. This view was based on limited fossil evidence, which made it difficult to grasp the full extent of the diversity and complexity that early mollusks exhibited. However, the discovery of Punk and Emo has provided researchers with a wealth of new information, forcing a rethinking of how these creatures evolved and adapted to their environment.
The names of the fossils—Punk ferox and Emo vorticaudum—were given by the research team as a lighthearted reference to their distinctive features and “rebellious” nature. Punk, in particular, with its spiky appearance, is reminiscent of a punk rock aesthetic, while Emo, with its more delicate form, complements the name perfectly. Despite the playful names, the fossils themselves are anything but trivial. They offer invaluable insights into the early development of mollusks and challenge preconceived notions about their early evolutionary history.

The research team, led by Dr. Mark Sutton from Imperial College London, collaborated with experts from various institutions, including the University of Leicester, the University of Oxford, the Senckenberg Research Institute, the Natural History Museum Frankfurt, and Yale University. Their study, published in Nature, employed advanced imaging techniques, including X-ray scanning and 3D digital modeling, to create “virtual fossils” that revealed intricate details of both the internal and external structures of the specimens. This approach allowed the researchers to preserve the fossils’ delicate features while gaining unprecedented insight into their morphology and behavior.
The fossils of Punk and Emo were exceptionally well-preserved, an uncommon occurrence for fossils of such ancient mollusks. The preservation of soft tissues, which is rare in fossil specimens, proved invaluable in providing a clearer picture of the mollusks’ physical traits and their evolutionary significance. Using X-ray scanning, the researchers were able to examine the internal structures of the fossils in fine detail without causing any damage to the specimens. By grinding down the fossils in thin layers and taking photographs at each stage, they were able to reconstruct the external features in three-dimensional digital models, revealing more about these ancient mollusks than ever before.
One of the most striking revelations was that both Punk and Emo displayed unique features that set them apart from other known mollusks, both living and extinct. For example, both fossils had smooth undersides, indicating that they likely lived on the sea floor, a habitat typical for many mollusks today. However, it was the fossils’ unconventional movement strategies that truly set them apart.
Emo, the more worm-like of the two, was preserved in a folded posture, suggesting it moved in a manner similar to an inchworm. The creature likely used its spines to grip the substrate and push forward in a manner akin to the crawling motion of modern-day inchworms. This discovery suggests that Emo had evolved a highly specialized and efficient means of locomotion that may have been well-suited to its environment.
Punk, on the other hand, presented more of a mystery. Researchers are still unclear as to how Punk moved, but they found that it had a ridge-like foot, a feature not seen in any modern mollusk. This foot, coupled with its long spines, indicates that Punk may have had a unique mode of movement that set it apart from other mollusks in its time. Its body structure was also quite unusual, with features resembling both worm-like mollusks and chitons, suggesting that Punk may have been capable of diverse movement strategies, enabling it to adapt to various environmental conditions.
The blend of characteristics found in these two fossils provides a crucial piece of the puzzle in understanding the evolutionary history of mollusks. Both Punk and Emo possess features that link them to both worm-like mollusks and chitons, a diverse group of mollusks known for their distinctive shell plates. This combination of traits helps researchers map out the mollusk evolutionary tree, offering a more complex and diverse picture of how mollusks evolved over time. Far from being simple and primitive, the early Aculiferan mollusks represented a group that was rich in evolutionary potential, capable of adapting to a wide range of environments and challenges.
The study of these ancient mollusks not only sheds light on the evolution of a major animal group but also offers insights into the broader processes of evolutionary diversification. The findings suggest that early mollusks, including those in the Aculifera group, were far more varied and adaptable than previously believed, with different species employing a range of locomotion strategies and occupying diverse ecological niches. This discovery challenges the idea that early mollusks were “basic” organisms, instead showing that they were capable of much more sophisticated behaviors and structures.
Moreover, this discovery underscores the importance of advanced imaging techniques in paleontological research. The ability to create virtual models of fossils and examine them in three dimensions has opened up new possibilities for studying ancient life forms. For many years, paleontologists were limited by the physical condition of fossils, particularly those that lacked well-preserved soft tissues. With the advent of X-ray scanning and other imaging technologies, however, scientists can now explore the internal and external structures of fossils with unprecedented clarity, leading to groundbreaking discoveries like that of Punk and Emo.
Reference: Mark Sutton, New Silurian aculiferan fossils reveal complex early history of Mollusca, Nature (2025). DOI: 10.1038/s41586-024-08312-0. www.nature.com/articles/s41586-024-08312-0