Oldest reptile skin impressions discovered in the Thuringian Forest

An international research team led by Dr Lorenzo Marchetti of the Museum für Naturkunde Berlin has described the oldest known reptile skin impressions to date, discovered in the Thuringian Forest. Another remarkable finding is the possible evidence of a cloacal opening in the skin impression.The fossils, which are approximately 298 to 299 million years old, date from the Early Permian and document, for the first time, detailed scaling patterns of the ancestral group of modern reptiles. The findings were published today in a scientific study in Current Biology.

The exceptionally well-preserved skin impressions were discovered alongside fossilised resting and footprints of early archosaurs in the Goldlauter Formation. The sites include the Cabarz quarry near Tabarz and Floh-Seligenthal. Modern radiometric dating of volcanic ash layers allows for precise chronological dating of the finds, making them the oldest direct evidence of reptile skin to date.

Skin structures such as scales, feathers or remnants of horned beaks are documented in a large number of dinosaur fossils, sometimes in the form of organic matter and sometimes only as impressions of the skin surface. “Such soft tissue structures are extremely rare in the fossil record – and the further back we go in Earth’s history, the more exceptional they become,” explains Dr Lorenzo Marchetti. “The tracks from the Thuringian Forest open up new perspectives on the early development of reptiles and their skin structures.”

The newly described trackways have been named as a new genus and species, Cabarzichnus pulchrus. The associated footprints exhibit proportions similar to those of the bolosaurs – an early group of reptiles from the lineage of modern lizards. The scale shapes range from diamond-shaped to hexagonal to laterally pointed and show remarkable parallels to later skin structures of various groups of terrestrial vertebrates.

Particularly exceptional is the possible evidence of a cloacal opening in the skin impression near the base of the tail. Most terrestrial vertebrates have a cloaca – a single opening for the excretion of faeces and urine, which also serves as the outlet for the reproductive organs. Only in live-bearing mammals are there separate openings. In the fossil record, the cloaca is almost never preserved as part of the soft tissue and is rarely clearly recognisable. However, the skin impression from Cabarz shows the trace of a cloacal opening near the base of the tail. The impression of the narrow slit suggests that the cloaca of the Cabarzichnus track-maker differs in shape and orientation from that of dinosaurs and crocodiles, and instead resembles the cloaca of turtles, lizards and snakes.

With their description of resting tracks from the Thuringian Forest as part of the recently completed BMFTR research project BROMACKER, Dr Lorenzo Marchetti and his colleagues are drawing the attention of evolutionary researchers to the track fossil evidence and demonstrating that the consideration of fossil tracks can be important for obtaining a more complete picture of the evolution of early terrestrial vertebrates.

“Trace fossils are far more than mere footprints,” says Dr Marchetti. “They preserve anatomical details that would otherwise be completely lost and make a decisive contribution to a better understanding of the evolution of early terrestrial vertebrates.”

Publication: Marchetti et al., The earliest reptile body impressions with scaly skin, Current Biology (2026), https://doi.org/10.1016/j.cub.2026.01.036