Oldest Stomach Stone Fossil Found
Paleontologists have made an intriguing discovery: what is thought to be the oldest stomach stone fossil, estimated to be around 150 million years old. This find occurred along England’s famed Jurassic Coast, a UNESCO World Heritage Site celebrated for its vast geological history spanning the Triassic, Jurassic, and Cretaceous periods. The findings were detailed in a recent peer-reviewed article in the Journal of the Geological Society.
A Unique Find on the Jurassic Coast
The Jurassic Coast stretches nearly 100 miles from East Devon to Dorset and is renowned for its rich geological history spanning multiple eras. Dr. Steve Etches MBE found the 150-million-year-old stomach stone in Kimmeridge, Dorset. This remarkable find pushes back the timeline for similar fossils, adding nearly 59 million years to the known record of such stones.
These stomach stones, or gastroliths, usually form in the digestive systems of animals. However, pinpointing the exact species they come from can be tricky without skeletal evidence. Nigel Larkin, a paleontologist and Visiting Research Fellow at the University of Reading, noted, “Unless stomach stones are found preserved within a skeleton, it is almost impossible to tell what sort of animal it might have formed inside.”
Understanding Prehistoric Marine Reptiles
The size of the stone, combined with its geological context from Upper Jurassic clay, suggests it was formed inside a large marine reptile. Larkin pointed out that it likely originated from creatures like an ichthyosaur, plesiosaur, pliosaur, or even an ancient crocodilian. He clarified that this stone definitely didn’t belong to a dinosaur, which were land animals, but he emphasized its significance: “This is still a very exciting and rare discovery.”
Dr. Ivan Sansom, Senior Lecturer in Palaeobiology at the University of Birmingham, performed detailed microscopic analyses of the stone. His research confirmed that the specimen exhibited all characteristics typical of a calculus from a gastrointestinal tract, validating it as a genuine stomach stone fossil.
Insights into Ancient Diets
Gastroliths appear in a variety of both extinct and existing animals, serving purposes like aiding digestion or providing stability for aquatic creatures. The discovery of this ancient stomach stone offers new insights into how marine reptiles from the Jurassic seas processed food. It suggests that these creatures might have used gastroliths to grind food or help with buoyancy, much like some modern species do.
The preservation and age of this fossil make it a significant record for paleontologists, shedding light on the physiology and behavior of marine reptiles from 150 million years ago. The Jurassic Coast, with its continuous sedimentary layers, remains a treasure trove for such extraordinary discoveries, bridging ancient ecosystems with contemporary science.
