Deep inside an Oklahoma quarry, palaeontologists discovered a small fragment of skin that is rewriting the history books. The fossilised reptile skin, dated at 289 million years old, is the most ancient of its kind, significantly older than previously known examples, according to experts. The skin, discovered in the Richards Spur cave, is believed to have belonged to an early Permian reptile believed to belong to a reptile similar to Captorhinus aguti, which has pebbled scales similar to a crocodile. The discovery has shed light on the adaptation of ancient creatures to land long before the dinosaurs arrived on the scene, according to the lead researcher, Ethan Mooney, who described the find as “mind-blowing.”
Discovery of the oldest fossilised reptile skin in Oklahoma
Bill and Julie May, both experienced fossil collectors, discovered a small fingernail-sized piece in the limestone caves of Richards Spur, Oklahoma. This area has been known for producing many unique and exciting discoveries, but this particular piece was unique. It is a piece of Captorhinus aguti, dating back 289 million years, or the Early Permian period. It was analysed by Mooney and his team at the University of Toronto, and it was determined that it contained epidermal skin, the top layer of skin that helped these animals survive on land. “We were totally shocked… ” It’s completely unlike anything we would have expected,” Mooney said. This was published in Current Biology in January 2024.
Unique preservation in the Oklahoma cave
Richards Spur is interesting because everything came together in such a way that fine clay, oil, and low oxygen, which slows down decay, were all present. According to Mooney, “Animals would have fallen into this cave system… buried in very fine clay.” The Permian oil was present, and it mummified the skin, leaving it preserved in remarkable three-dimensional detail. Usually, in fossils, the skin decays quickly, but in this case, the epidermis was present in three dimensions. The stalagmites were dated as being between 286 and 289 million years old, as determined by uranium-lead dating. It is because of this unique combination that the skin of the Captorhinus was preserved, allowing scientists a unique look into the development of amniotes.
Features of the fossilised reptile skin
Imagine a surface with neat, non-overlapping scales, such as those on a crocodile. The way these scales are joined indicates flexibility, as seen in snakes and worm lizards, implying stretchy ancient skin. There is no skeleton, and the exact shape of the body remains a mystery, but it is clear that it was an early reptile. It has been described as the oldest known preserved epidermis, according to the study, which extends back more than 130 million years. This skin would have been protective for the wearer as they navigated the rough terrain, representing an early stage in the evolution of protective skin in vertebrates. According to Mooney, “the epidermis was an important characteristic for vertebrates to survive on land.”
Evolutionary insights from a reptile skin fossil
This discovery is a look at how vertebrates came to live on dry land as the Carboniferous period changed into the Permian period. The amniotes, or reptiles, birds, and mammals, needed waterproof skins to live out of the water. The skin of Captorhinus aguti displays ancient traits that remained around for a long time. “This is a remarkable opportunity to explore the very early steps of higher vertebrate evolution,” Mooney stated in the published paper. This helps bridge gaps in our understanding of early terrestrial vertebrate evolution, filling in a gap in the development of hides. We can imagine those first reptiles emerging out of caves with their scaly hides exposed to the sun and predators. These fossils are redefining our timeline of life’s adventurous move to land.
Why ‘Richards Spur’ yields such finds
Oklahoma’s Richards Spur isn’t any ordinary dig site, as it offers a peek into a time capsule from the Permian period. Animals fell in through shafts or were washed in by floods, only to end up in low-oxygen, muddy environments. Oil, which was present in prehistoric seeps, coated the bodies, preventing bacterial growth and slowing down decay. Quarry work every year digs up new strata, reminiscent of the Mays’ latest discovery. In previous digs, scientists have discovered the bones of Captorhinus, which match perfectly with the skin described in this discovery. “Every so often, we’re granted a rare chance to catch a glimpse of deep time,” note Mooney and his team of scientists. It is no wonder it is such a prime location for such preservation.
Impact on palaeontology and future hunts
This fossil of reptile skin thrills experts, indicating that there is more hidden in Permian caves. This fossil has also raised some questions about how fast skin evolved after the appearance of amniotes. The team of Mooney suggests that more scanning of the Richards Spur pieces should be done, as some of these pieces of bone could be skin. This has also drawn attention to other places worldwide that could be hiding similar treasures. “It’s an exceptional opportunity when you find an old skin fossil like this,” states Mooney. For hobbyists such as the Mays, this has shown that persistence is key. Who knows what other surprises are hidden in these Permian quarries?
