Chinese paleontologists have discovered the oldest representative of a flying fish. The fossil found in the south of China is 240 million years old and shows typical adaptations to flies: its chest and basin fins are enlarged like wings and the tail fin is extended downwards particularly long.
The researchers reported in the magazine "Proceedings of the Royal Society B" that a quick blow of this powerful tail fin has been enough to catapult the fish out of the water and allow it to slide over the water surface.
The first flier of the fish world
The newly discovered species was thus the earliest known vertebrate, which developed this type of movement. The Potanichthys xingyiensis baptized fossil is, however, not an ancestor of today's flying fish, but belongs to a completely different line of the fish-boom tree.
"Flying fish are extraordinary aquatic vertebrates that can glide over the water with the help of their enlarged fins up to 400 meters," write Guang-Hui Xu from the Chinese Academy of Sciences and his colleagues.
With 72 kilometers per hour across the sea
They partly lift off the water surface and reach speeds of 36 to 72 kilometers per hour - which is faster than a man can run. Decisive for this ability is not only the wing fins, but above all the powerful tail fin, enlarged towards the abdomen, explain the researchers. It creates the necessary thrust under water to propel the fish and catapult it out of the water.
This kind of movement, however, cost a lot of energy, says the researchers. Potanichthys xingyiensis and his relatives have therefore probably developed them as an emergency escape strategy.
display
"By jumping from the water, they escaped from predators like the large marine reptiles or large carnivorous fishes living at that time," write Xu and his colleagues. These lived in the same waters as Potanichthys and could reach up to three meters in length. The approximately 15-centimeter-sized flying fish was probably a suitable prey for them.
As the researchers report, the ancestors of all today's approximately 50 flying species developed only 65 million years ago after the fall of the dinosaurs. But there had already been another fish group, which had been extinct since then, which also had this unusual locomotion strategy.
Older fossils of flying fish are poorly preserved
However, fossil fossils from the period around 200 million years ago were only found in Austria and Italy so far. The newly discovered Potanichthys xingyiensis is the oldest representative of this group, says Xu and his colleagues. It is also so well preserved that the skull base and other body parts can be examined more closely for the first time.
The new find also throws a new light on the geographical distribution of the flying primeval fish. Potanichthys xingyiensis is the first fossil of this group found in Asia.
"This shows that these fish were spread both on the western and the eastern edge of the Paleoteths," write Xu and his colleagues. This sea once formed a deep incision in the ancient continent of Pangea, extending from the territory of today's Mediterranean to East Asia. "The new find provides new evidence that there was an exchange of aquatic invertebrates between Europe and Asia across this corridor in the Triad," the researchers say.