Site photographs of the two bone beds at (A) Lavernock Point and (B) St Mary's Well Bay. The basal bone bed at Lavernock has a nearly continuous thickness of 5 cm, while the higher bed at St Mary's Well Bay has an approximate thickness of 1.5 cm.
Credit: Proceedings of the Geologists' Association (2024). DOI: 10.1016/j.pgeola.2024.05.001
A large fossil discovery has helped shed light on the history of dinosaurs in Wales. The find is reported in Proceedings of the Geologists' Association.
Until recently, the land of the dragon didn't have any dinosaurs. However, in the last 10 years, several dinosaurs have been reported, but their life conditions were not well known.
In a new study by a team from the University of Bristol, important details have been revealed for the first time. The researchers found that early Welsh dinosaurs, from more than 200 million years ago, lived on a tropical lowland beside the sea. Dinosaur trackways are known from Barry and other sites nearby, showing that dinosaurs had walked across the warm lowlands.
The discovery was made at Lavernock Point, close to Cardiff and Penarth, where the cliffs of dark-colored shales and limestones document ancient shallow seas. At several levels, there are accumulations of bones, including the remains of fish, sharks, marine reptiles and occasionally, dinosaurs.
Former student of the Bristol MSc in Paleobiology Owain Evans, who led the study, explained, "The bone bed paints the picture of a tropical archipelago, which was subjected to frequent storms, that washed material from around the surrounding area, both in land and out at 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.
"I had visited the coast at Penarth all my life, growing up in Cardiff, but never noticed the fossils. Then, the more I read, the more amazing it became. Local geologists had been collecting bones since the 1870s, and most of these are in the National Museum of Wales in Cardiff."
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: Proceedings of the Geologists' Association (2024). DOI: 10.1016/j.pgeola.2024.05.001
Cindy Howells, Curator of Paleontology at the National Museum of Wales, adds, "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 ensure that it remains one of the most significant localities for paleontology in Wales."
Two discoveries made by the team while conducting fieldwork at Lavernock were the fossilized remains of a placodont osteoderm, and a single coelacanth gular bone.
Supervisor Dr. Chris Duffin said, "The remains of coelacanths and placodonts are relatively rare in the U.K., which makes these finds even more remarkable. These two fossils alone help build a broader picture of what the Rhaetian in the U.K. would have looked like."
Professor Michael Benton from Bristol's School of Earth Sciences, another project supervisor, adds, "The volume of dinosaur remains found at Lavernock is extremely exciting, and is a chance to study a complex, and often mysterious period in their evolutionary history. We have identified the remains of a large Plateosaurus like animal, along with several bones which likely belonged to a predatory theropod."
A significant section of the paper is dedicated to the abundant microfossils found at the site, which include fish teeth, scales and bone fragments. By examining thousands of specimens, the team was able to identify the key species in the shallow seas and work out the relative importance of each.
The origins of the Welsh dragons have been pinned down at last.
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