The sail-backed Spinosaurus is one of the largest carnivorous dinosaurs ever discovered, able to reach nearly 50 feet long! The exact purpose of its distinctive spines that give it its name is unknown - some scientists believe it was used to regulate temperature, while others believe it may have been used for display to make the dinosaur more attractive to potential mates. Some even believe it may have had a large hump instead of a sail!
Spinosaurus was first discovered in 1915. However, it was onlyknown from a few bones, so other than the large spines on its back,it wasn't really known what the rest of it looked like. Theseoriginal Spinosaurus bones were destroyed during World War II.
Later material discovered in the 1990s and early 2000s gave moreinsight into this Cretaceous predator, including parts of the headthat showed its snout was long and narrow like that of a crocodile.This unique head showed that Spinosaurus was related to similardinosaurs like Suchomimus and Baryonyx, and also hinted that it mayhave hunted fish.A partial skeleton described in 2014 radicallychanged the way Spinosaurus was viewed, as it showed very differentbody proportions than previous reconstructions, including muchshorter hind limbs. This new description seemed to indicate thatSpinosaurus was more suited to an aquatic lifestyle with a bodybuilt for swimming, and may have occasionally walked on four legsinstead of two.