Tanystropheus was a reptile and has been found in Italy and Switzerland. This animal lived during the Triassic period, approximately 200 million years ago. It reached lengths of up to six meters and lived by fishing in the sea, using its long neck and sharp teeth. Its hind limbs were well-adapted for fast swimming and resembled the legs of a frog.

Upon hatching, the juveniles were about 22 centimeters long and remained on land, feeding on insects. Upon reaching a certain age, they moved to coastal areas and lived on a diet of fish.