Plesiosaurs lived in the world's oceans for much of the Mesozoic Era (203–66 million years ago). These reptiles, which could grow up to 12 meters long, fed on fish and moved much like sea turtles using four paddle-like flippers. Until now, little has been known about the external anatomy of plesiosaurs. However, in a new study published in the scientific journal Current Biology, a research team led by scientists from Lund University has managed to analyze soft tissue from a 183-million-year-old plesiosaur found near Holzmaden, Germany.
"Fossilized soft tissue, such as skin and internal organs, is exceptionally rare. We used a broad range of techniques to identify smooth skin in the tail region as well as scales along the rear edge of the flippers. This provided us with unparalleled insights into the appearance and biology of these long-extinct reptiles," says Miguel Marx, a PhD student in geology at Lund University and the lead author of the study.
The results reveal an unusual combination of smooth and scaly skin on different parts of the body. The researchers believe this variation could be related to different functions. The plesiosaur needed to swim efficiently to catch fish and squid-like animals, a task made easier by its smooth and hydrodynamic skin. However, it also needed to move across rough seafloors, which the scaly flippers would have likely allowed it to do.
"Our findings help us create more accurate life reconstructions of plesiosaurs, something that has been extremely difficult since they were first studied over 200 years ago. Also, the well-preserved German fossil really highlights the potential for soft tissue in providing valuable insights into the biology of these long-extinct animals," explains Miguel Marx.
By reconstructing the appearance of ancient animals, researchers can enhance our understanding of macroevolution and the adaptations required to survive in specific environments. In recreating the past, we can also better understand Earth’s history and where we are headed.
"Apart from the mosaic of smooth skin and scales, it was an incredible moment to visualize the cells in thin sections of the fossilized plesiosaur’s skin. I was shocked when I saw skin cells that had been preserved for 183 million years. It was almost like looking at modern skin," says Miguel Marx.
