Spinosaurids are a group of large, carnivorous dinosaurs known for their distinctive elongated skulls and crocodile-like teeth. They lived during the Late Jurassic to the Late Cretaceous periods, primarily in what is now Africa, Europe, and South America. Their unique adaptations suggest they may have been semi-aquatic, hunting both land and aquatic prey. One of the most famous spinosaurids is Spinosaurus, which is recognized for its sail-like structure on its back formed by elongated neural spines. This dinosaur could grow up to 50 feet long, making it one of the largest known carnivorous dinosaurs. Spinosaurids are believed to have had a diverse diet, including fish and other small dinosaurs.