Spinosaurus remains one of the most controversial predators in dinosaur history. The initial idea —put forth after the discovery of more complete fossils in 2014—was that it was a fully aquatic predator, using a paddle-like tail, dense bones, and crocodile‐style jaws to hunt fish underwater.  A 2022 study found that Spinosaurus and its close relative Baryonyx had unusually dense thigh and rib bones—structures similar to those in animals adapted for submerging in water (like penguins or manatees