Ichthyosauromorphs are marine reptiles that flourished in the Triassic and Jurassic periods. They first appeared about 250 million years ago and became extinct 90 million years ago, about the same as dinosaurs.
The creatures discovered so far first appeared in the Early Triassic, and have been reported in Japan, Canada and northern Europe, as well as in China's Hubei and Anhui provinces and other places. Most are small, measuring no more than 1.5 meters long, but the Guangxi fossil is much larger.