Spinosaurus

The Spinosaurus is a three-part fossil that can be donated by the player to the museum in

Completing the Spinosaurus in New Leaf
"The spinosaurus is famous for the sail on its back, made up of skin stretched over spikelike bones. The assumption is that these sails were used to help regulate body temperature, common for reptiles. In addition to having this large sail, it is also the largest of the carnivorous dinosaurs. Despite being so commanding, its diet most likely consisted of fish from swampy, marshy regions."