A large fossil discovery has significantly advanced our understanding of dinosaur history in Wales, a region previously believed to be devoid of these prehistoric giants.

View of the cliff face at Lavernock Point from the east end of the beach, showing the red mudstones of the Williton Member (Mercia Mudstone Formation) transitioning upwards into the interbedded shales of the Westbury Formation. Credit: Owain Evans et al, Proceedings of the Geologists’ ᴀssociation (2024)

Over the past decade, several dinosaur fossils have been reported in Wales, but details about their living conditions remained unclear. Now, a comprehensive study conducted by a team from the University of Bristol and published in the Proceedings of the Geologists’ ᴀssociation has revealed critical insights into the ancient ecosystems where these dinosaurs thrived.

The research team, led by former Bristol MSc student in Palaeobiology, Owain Evans, uncovered that early Welsh dinosaurs lived over 200 million years ago on a tropical lowland adjacent to the sea. Dinosaur trackways found in Barry and other nearby sites indicate that these prehistoric creatures roamed the warm lowlands.

Footprint found in Triᴀssic rocks from South Wales, likely from a small theropod. Credit: Cindy Howells at the National Museum of Wales/University of Bristol

The discovery site, Lavernock Point, is located near Cardiff and Penarth. This area, characterized by cliffs of dark-colored shales and limestones, documents ancient shallow seas. At various levels within these rock formations, accumulations of fossilized bones have been found, including remains of fish, sharks, marine reptiles, and occasionally, dinosaurs. These fossil deposits offer a vivid picture of the diverse marine life that once existed in these prehistoric environments.

Evans explained: “The bone bed paints the picture of a tropical archipelago, subjected to frequent storms that washed material from both land and sea into a tidal zone. This means that from just one fossil horizon, we can reconstruct a complex ecological system, with a diverse array of marine reptiles like ichthyosaurs, plesiosaurs, and placodonts in the water, and dinosaurs on land.”

Cindy Howells, Curator of Palaeontology at the National Museum of Wales, noted: “The collections from Lavernock go all the way back to the 19th century, with many sections of the bone bed being collected over the years. The presence of dinosaur fossils at the site ensures that it remains one of the most significant localities for paleontology in Wales.”

Fossilized impression of a dentary bone, described by Newton (1899), from Stormy Down, South Wales. Credit: Owain Evans et al, Proceedings of the Geologists’ ᴀssociation (2024)

During their fieldwork, the team made two notable discoveries: the fossilized remains of a placodont osteoderm and a single coelacanth gular bone. Dr. Chris Duffin, one of the project supervisors said: “The remains of coelacanths and placodonts are relatively rare in the UK, which makes these finds even more remarkable. These two fossils alone help build a broader picture of what the Rhaetian period in the UK would have looked like.”

The study also uncovered a significant number of dinosaur remains, including those of a large Plateosaurus-like animal and several bones likely belonging to a predatory theropod.

Red dragon sculpture on top of the Cromlech at the Welsh Memorial Park, Ypres. Credit: Rickfive/Wikipedia (Creative Commons Attribution-Share Alike 4.0 International)

A substantial portion of the research paper is dedicated to the abundant microfossils discovered at the site, such as fish teeth, scales, and bone fragments. By meticulously examining thousands of specimens, the team identified the key species inhabiting the shallow seas during that period and determined their relative importance within the ecosystem. This comprehensive analysis has provided a scientific explanation for the origins of the fossils colloquially referred to as “Welsh dragons,” thereby pinning down their historical presence in the region.

University of Bristol

More information: Owain Evans et al, (2024). Microvertebrates from the basal Rhaetian Bone Bed (Late Triᴀssic) at Lavernock, South Wales, Proceedings of the Geologists’ ᴀssociation. DOI: 10.1016/j.pgeola.2024.05.001