Sometimes the tail wags the dinosaur.
The story of Spinosaurus, a Late Cretaceous creature living some 93-112 million years ago, has been clouded in mystery. After a partial skeleton was discovered in 1912, in Egypt, the fossil was placed on view in Munich and was later destroyed during World War II. Drawings remained, however, and just a handful of bones discovered years later. Scientists were content to consider it among the largest of dino carnivores to roam the land. Dinosaurs dwelled on terra firma, after all.
Now, Spinosaurus is moving closer to being recognized as the first known aquatic dinosaur.
A team of paleontologists led by Nizar Ibrahim of the University of Detroit Mercy returned to Egypt in 2014 and unearthed more bones. Aspects of the fossil remains indicated features resembling modern manatees, an aquatic mammal. Many scientists, though, were skeptical that Spinosaurus spent its life underwater.
But when Ibrahim and his researchers recently returned to the site, they found a long, narrow tail. The structure was paddle-like, including upward-pointing bony spines and downward chevrons. Spinosaurs also sport a crocodilian snout and nostrils, and lived close to North African waters, mangroves, and tidal flats.
But the tail clinched it: Spinosaurus had a robust means of propulsion—a strong tail that probably from side to side—to comfortably inhabit the water. A paper describing their findings was published last year.
Commanding in its presence, Spinosaurus apparently ruled the Late Cretaceous seas.