Scientists Find Prehistoric Reptile Skin Preserved in Stone, Dating Back Nearly 300 Million Years

Fossilized skin impressions uncovered in central Germany are now regarded as the oldest known evidence of reptile skin. Dating backroughly 298 to 299 million years, the find preserves intricate scale patterns and may even include a cloacal opening.

The international research team, led by Dr. Lorenzo Marchetti of the Museum für Naturkunde Berlin, analyzed the material from the Thuringian Forest and published their findings in Current Biology. According to the researchers, these impressions represent the first detailed documentation of scale patterns from the stem lineage of modern reptiles.

Exceptionally Rare Soft Tissue Preservation

The skin impressions were discovered in association with fossil resting traces and footprints of early reptiles. The newly described resting traces have been named Cabarzichnus pulchrus. The footprints display proportions similar to those of bolosaurians, an early reptile group belonging to the stem lineage of modern lizards.

Skin structures such as scales, feathers, or horny beaks are known from numerous dinosaur fossils, sometimes preserved as organic material and sometimes as surface impressions. Yet such finds become increasingly scarce deeper in geological time. As Dr. Lorenzo Marchetti explained:

“Such soft tissue structures are extremely rare in the fossil record—and the further back we look in Earth’s history, the more exceptional they become,” He added that, “the traces from the Thuringian Forest open new perspectives on the early development of reptiles and their skin structures.”

The documented scales range from diamond-shaped to hexagonal and laterally pointed forms. As explained in the study published in Current Biology, these shapes show strong similarities to skin structures observed in later groups of terrestrial vertebrates.

Possible Cloaca Found in Ancient Fossil

Researchers were particularly intrigued by a possible cloacal opening preserved near the tail base. Cloacas are common among land vertebrates, serving both reproductive and excretory functions, except in placental mammals.

Soft tissues rarely survive the fossilization process, and recognizable cloacal structures are almost unheard of. In this case, scientists identified a slender, slit-shaped mark near the tail base. According to the research, its form suggests that the cloaca of the Cabarzichnus trackmaker was unlike that of dinosaurs or crocodiles, appearing instead more similar to those seen in turtles, lizards, and snakes.

Even preserved only as an impression, such a structure is exceptionally rare and reveals anatomical details that bones alone cannot capture.

Trace Fossils as Evolutionary Evidence

Through the documentation of these resting traces within the BROMACKER project, Marchetti and his team underscore the broader scientific value of trace fossils. Their findings demonstrate that impressions and tracks can retain anatomical features rarely preserved in traditional skeletal fossils.

“Trace fossils are far more than simple footprints.” He noted, “they preserve anatomical details that would otherwise be completely lost and play a key role in improving our understanding of the evolution of early terrestrial vertebrates.”

The Thuringian Forest impressions provide a detailed snapshot of reptile skin anatomy from the early Permian.

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