👉 Limnognathida is a group of extinct marine reptiles that lived during the Cretaceous period, approximately 68 million years ago. They were characterized by their long necks and distinctive beak-like teeth, which they used for feeding on algae and other plants. Limnognathida had a unique adaptation for swimming in cold water environments. This included a streamlined body shape with large limbs that could be swam to the surface of the water. Additionally, they had an elong