For many years, the scientific community firmly believed that dinosaurs which later came to be related to birds were strictly land-dwelling creatures. Although some dinosaurs, like the Plesiosaur, did evolve to live in the water, they were quite different from dinosaurs like the T-Rex, Triceratops, or Velociraptor.
A new fossil discovery, however, has led many to rethink these views. It seems the Spinosaurus, once thought to be a land-dwelling dinosaur, may actually be the first true swimming dinosaur.
Appearance and Body Structure
- 13 to 22 tons in weight
- 46 to 59 feet in length
The Spinosaurus aegyptiacus was first discovered in the early 1900s when Ernst Stromer discovered pieces from several different skeletons. Stromer knew there was something interesting about the dinosaur’s body. However, because he only found fragments and never a full skeleton, he wasn’t quite sure what it was.
Stromer’s original skeletons were destroyed in 1944, but other pieces of skeletons were discovered throughout the 1900s and 2000s. Scientists found that Spinosaurus most likely weighed between 13 and 22 tons. Its body would have been between 46 and 59 feet long, with a skull measuring six feet. The dinosaur stood on its hind legs, much like a T-Rex, and had a long, narrow snout. The dinosaur also had a large sail along its spine.
Evidence for a Life in the Water
- Narrow jaw with straight teeth
- Nostrils high up near the eyes
- Fish scales found in Spinosaurus skeletons
For many years, scientists had speculated that Spinosaurus hunted in the water. Evidence of fish scales had been discovered in the stomach region of some skeletons. Also, the narrow snout of the dinosaur was shaped perfectly for hunting in the water. The nostrils were closer to the eyes than the end of the snout. The teeth, unlike most carnivorous dinosaurs, were straight, all of which pointed towards a life spent catching and eating fish.
However, many people studying the Spinosaurus believed the dinosaur was most likely terrestrial and did not do much swimming. Recent discoveries, however, have proved that this may not have been the case.
An Oar-Like Tail
Until recently, no complete skeleton of a Spinosaurus had been discovered. Scientists had no real idea of what the tail of the dinosaur looked like. When the tail bones were finally discovered in April of 2020, they answered many questions about how the dinosaur lived.
The Spinosaurus’s tailbones were much taller than expected. Additionally, the shape is similar to an oar or a fin. This tail would have been able to generate a large amount of thrust, propelling the Spinosaurus through the water and swimming well enough to hunt large prey.
Thanks to other fossil evidence, such as Spinosaurus teeth imbedded in the bones of terrestrial dinosaurs, researchers believe that Spinosaurus was as comfortable on land as it was in the water. Most scientists guess that Spinosaurus mainly hunted in the shallows. However, the discovery of the first swimming dinosaur has completely changed how we view dinosaur evolution. It has led to new and exciting thinking in the scientific community.