340-Million-Year-Old Tetrapod Footprints Uncovered in UK
Paleontologists have discovered an ancient tetrapod (land vertebrate) trackway in North Yorkshire, England, dating back to the Carboniferous period. Made about 340 million years ago, it’s the oldest known tetrapod trackway ever found in the United Kingdom.
The Carboniferous trackway was first discovered in 1977 by S.J. Maude near the waterfall Hardraw Force in Wensleydale, the north Yorkshire Dales.
Assigned to the ichnogenus Palaeosauropus, the prints were made by an edpoid temnospondyl, a primitive semiaquatic amphibian.
“Temnospondyls were highly successful animals, appearing during the Carboniferous period and evolving over the next 210 million years into a wide variety of forms,” the paleontologists explained.
“While some were about the same size as modern-day amphibians many grew to enormous sizes.”
“Some of these things were large crocodile-like animals at least two meters long with big heads,” said Dr. Angela Milner, a researcher in the Department of Earth Sciences at the Natural History Museum, London.
“They have been nicknamed by some of my colleagues as croco-manders, because they look like a crocodile but had the same lifestyle and walked the same way as salamanders.”
In order to better visualize the Hardraw trackway, Dr. Milner and colleagues 3D scanned the specimen.
“We used scanning and photography to make a 3D digital model, allowing us to better visualize and identify the footprints and invertebrate traces,” explained Hannah Bird, a researcher with Dudley Museum and assistant curator of Carboniferous specimens at the Virtual Natural History Museum.
“Determining whether individual prints were made by hands or feet, as well as the direction of movement, certainly proved troublesome at times but we were finally able to reconstruct how this amphibian might have moved in life.”
“It was revealed that the edpoid walked across the sandy bed of river delta along with contemporary invertebrate animals including arthropods, worms and mollusks.”
The team’s paper was published in the Journal of the Geological Society.
Hannah C. Bird et al. A lower Carboniferous (Visean) tetrapod trackway represents the earliest record of an edopoid amphibian from the UK. Journal of the Geological Society, published online December 12, 2019; doi: 10.1144/jgs2019-149