The county of Herefordshire in England is known for its rolling green hills and quaint pastoral charm. It hardly seems like the place for punk and emo culture to make a splash. Yet, beneath this serene English landscape lies a treasure trove of prehistoric secrets. Now, that treasure trove includes two extraordinary fossils whimsically named Punk ferox and Emo vorticaudum.

These ancient mollusks, discovered in the Silurian Herefordshire Lagerstätte, once thrived in a marine world far removed from today’s tranquil farmlands. The ancient creatures challenge longstanding ideas of mollusk development and highlight a previously unknown diversity in body plans.

The two mollusks date to the Silurian Age, some 430 million years ago, long before the age of the dinosaurs. They lived in the sea before fossilizing in the so-called Herefordshire Lagerstätte, a well-known geological formation. However, these fossils are not what researchers were expecting to find.

Their names derive from visual features reminiscent of the punk and emo styles, such as spine arrangements likened to hairstyles and the presence of fringed structures:

• Punk Ferox: This worm-like mollusk had a worm-shaped body lacking traditional shell valves. It also featured bristles with elongate spicules on its back that likely served as protection against predators. The ventral (front) surface featured about 25 pairs of gills. The gills were concentrated along its posterior, and a foot-like structure. This is different from the flat sole typical of modern mollusks.

• Emo Vorticaudum: Sporting two small, shell-like valves near its head and a tapering tail encased in a spiral of spines, Emo vorticaudum also lacked a traditional foot. Instead, it featured a smooth ventral surface with hints of respiratory and digestive structures.

Why these fossils are special

Mollusks are the second-largest animal phylum in the world, trailing only arthropods — a diverse group that includes insects, spiders, and crustaceans. Scientists estimate there could be as many as 200,000 mollusk species on Earth today. Despite this immense diversity, all mollusks fall into two primary categories. First, there are the conchiferans, which include familiar creatures like snails, clams, and octopuses. Then, there are the aculiferans, an eclectic group characterized by spines, unusual body shapes, and what can be described as “weird molluscan worms.”

The fossils are striking because they deviate from traditional molluscan forms. Modern mollusks, including gastropods, bivalves, and cephalopods, exhibit a wide variety of body plans. However, this particular group, aculiferans, were long thought to be morphologically conservative, representing primitive offshoots of the molluscan lineage. This is not the case with the emo and punk fossils.

Both species were reconstructed using advanced imaging technologies, including physical-optical tomography and synchrotron X-ray microtomography. These methods provided 3D views of their anatomy, revealing unique combinations of features previously unseen in mollusks.

“Mollusks are one of the most diverse groups of living animals including slugs and snails, clams, octopus, and squids. Less familiar mollusks are coat-of-mail shells (chitons), and so-called ‘spicule worms’ (aplacophorans) which lack a shell and have a worm-like body,” said Yale paleontologist Derek Briggs, co-author of a new study in Nature.

“Both new fossils have a spectacular array of long spicules on their upper surface reminiscent of the hairstyles associated with performers of punk rock and its derivative emo which inspired the scientific names of these new forms,” said Briggs, the G. Evelyn Hutchinson Professor of Earth and Planetary Sciences in the Faculty of Arts and Sciences. “These animals reveal that the group including chitons and aplacophorans — long considered to be much more limited in form than the more familiar groups of mollusks — were remarkably diverse in the distant past compared to the present day.”

Evolutionary surprises

Mollusks are notoriously underrepresented in the fossil record due to the rarity of preserving soft-bodied forms. This scarcity makes every well-preserved specimen invaluable, especially when they capture unique morphologies that redefine our understanding of early life.

The Herefordshire Lagerstätte, with its exceptional preservation, has already offered glimpses into Silurian marine ecosystems. But the discovery of Punk ferox and Emo vorticaudum provides the first detailed look at how early aculiferans might have lived and adapted to their environments.

These fossils push back against the idea that aculiferans were evolutionarily stagnant. Instead, they demonstrate that aculiferans were highly innovative. They had traits that evolved, reversed, and converged in ways that challenge traditional evolutionary models.

The discovery of Punk ferox and Emo vorticaudum is a reminder of how much remains to be learned about life’s evolutionary history. With advances in technology, such as digital tomography and 3D reconstruction, paleontologists can extract more information than ever before from fossil specimens.

The study was published in Nature.