What scientists learned from a well-preserved fossil of this iconic Jurassic-era species
The discovery of a well-preserved fossil is helping researchers learn more about an iconic Jurassic-period species.
The plesiosaur, considered a successful marine predatory ancient species, may have been aided in its underwater hunting endeavors by turtle-like scales that covered its body -- which scientists have now discovered due to the presence of soft tissue in a newly unearthed fossil, according to a paper published earlier this month in Current Biology.
Researchers from Lund University in Sweden have been analyzing the soft tissue from a 183 million-year-old plesiosaur for the first time in history after the fossil was found intact near Holzmaden, Germany.
Fossilized soft tissue, such as skin and internal organs, is "exceptionally rare" in plesiosaur fossils, Miguel Marx, a Ph.D. student in geology at Lund University and the lead author of the study, said in a video published on the university's website.
The preserved skeleton of the plesiosaur is articulated with fossilized soft tissue from the tail and one of the flippers, he said.
"I was shocked when I saw skin cells that had been preserved for 183 million years," Marx said. "It was almost like looking at modern skin."
The specimen reveals that the plesiosaur had both smooth and scaly skin, which likely helped it swim rapidly and move along rough seabeds, according to the researchers.
"This mosaic of scales and scaly skin has never been reported before in a plesiosaur, and thanks for this amazing find, we now have a much better appreciation of what these animals might have looked like while alive," Johan Lindgren, an associate professor of geology at Lund University, said in a statement.
Plesiosaurs were considered among the most successful marine hunters of their time. The long-necked animal grew to nearly 40 feet long and had four paddle-like flippers that allowed them to swim like sea turtles.
The species was first studied 200 years ago, but little was known about the external anatomy of the plesiosaur until the newest fossil was discovered. Plesiosaur fossils can be found all over the world, Marx said.
The combination of both smooth and scaly skin is unusual, and it had different functions, the researchers said. The plesiosaur's smooth and hydrodynamic skin allowed it to swim efficiently to catch fish and other squid-like animals, but its scaly flippers likely helped them move across rough sea floors by providing protection and traction.
Without the presence of the soft tissue, Marx would have assumed the plesiosaur would be scaleless, like other marine predators of the time, he said.
"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," Marx said. "This provided us with unparalleled insights into the appearance and biology of these long-extinct reptiles."
The findings will also help researchers enhance the understanding of macroevolution and how species adapted to specific environments over time, according to the paper.
"The discovery of scales was surprising and changes our perceptions of how these animals would have adapted to their pelagic environment," Marx said.
Editor's note: This story has been updated to reflect that the plesiosaur is considered a successful marine predatory ancient species.
