Spinosaurus is a dinosaur that breaks the rules. From the tip of its crocodilelike snout to the end of its paddle-shaped tail, this enormous predator was more comfortable sculling around Cretaceous lakes than stomping after prey on land. No other carnivorous dinosaur that we know of lived like this.
But Spinosaurus is still changing. Our understanding of the water-loving beast is pieced together by scattered remains, and a full skeleton of the animal has never been found. Its image has morphed again and again over the decades as paleontologists slowly uncover details from its far-off past — most recently, the fossil of an oar-shaped tail, which confirmed suspicions that the creature was more active in water than on land.
“The look of Spinosaurus changed a lot [over the years], due to scanty finds and difficulty in comparing anatomical parts from different specimens and species,” says Milan Natural History Museum paleontologist Cristiano Dal Sasso. While the first fossils were discovered over 100 years ago, other pieces of Spinosaurus — such as vertebrae, jaw bones and tail bones — have been excavated since.
