It is called "Ichthyosaur", but it is neither a "fish" nor a "dragon". It was once the "overlord" of the Triassic Ocean!

The most serious mass extinction event in geological history occurred at the end of the Permian period, leading to the collapse of the Paleozoic ancient ecosystem. Since then, many branches of reptiles have developed into the ocean and evolved into marine reptiles such as ichthyosaurs, fin dragons, and sea dragons.

Early ichthyosaurs resembled lizards, but after mid- to late-stage evolution, their morphology became closer to that of fish. They are generally believed to have first appeared in the late Triassic period and disappeared around the late Cretaceous period, roughly the same period as dinosaurs, and once occupied the top of the marine ecological food chain. In order to better adapt to life in the water, they are highly specialized, and their bodies have evolved into streamlined bodies that are most suitable for swimming in the water. They are ferocious and feed on other marine animals. Their strong limbs used for crawling on land have evolved into flippers used to maintain body balance in the water, and their long and thin tail has evolved into a strong tail fin. They have lungs and breathe with them, so every once in a while, ichthyosaurs have to come to the surface of the water to breathe.

The Ancient Ocean Exhibition Hall displays a relatively complete Guishan Chaohu Ichthyosaur fossil. It is a small ichthyosaur that was only about 0.5 meters long when alive, with a skull length of about 6 centimeters. It was named by Mr. Yang Zhongjian and Mr. Dong Zhiming in 1972. It is also a relatively primitive ichthyosaur species and the earliest ichthyosaur species found on Earth. Its contemporaries include the Utsu Ichthyosaur from Miyagi Prefecture, Japan and the Brachyura Ichthyosaur from Spitzbergen Island, Europe. Although Guishan Chaohu Ichthyosaur has fully adapted to aquatic life and can swim in the sea in an eel-like manner, its reproductive behavior still retains the characteristics of cephalic viviparity of terrestrial reptiles.

The fossil discovery made by the team of Chinese and foreign scientists in the Chaohu area of ​​Anhui Province shows that marine reptiles had already shown a high degree of diversity in the Early Triassic. The Anhui Chaohu dragon fauna is also known as one of the most complete and primitive Mesozoic marine fossil groups. They represent the end of the dormant period and the beginning of the radiation period of the Early Triassic marine ecosystem. They are an important scene that witnessed the recovery of marine life after the Permian mass extinction.