In 2014, one paleontologist’s dino-mite discovery led to a conversation about where dinosaurs spent their days. Did they all roam Earth or did they swim? We turned to National Geographic's “Mister Big” to introduce you to a dinosaur like you’ve never seen before.
Imagine: It’s the middle of the Cretaceous period, about 100 to 94 million years ago. You’re standing in what is today’s southeastern Morocco. Dinosaurs, including at least three great predators roam Earth’s lands. Six or seven types of crocodiles and 8- to 25-foot fish swim through the rivers. Large reptiles fly through the sky.
How can all of these predators coexist?
In a quest to answer that question, paleontologist Nizar Ibrahim made an even bigger discovery– the first known dinosaur that spent a substantial amount of time in water.
Meet Spinosaurus aegyptiacus.
This is a dinosaur that stretches 50 feet long from nose to tail with a six- to seven-foot smooth sail on its back. Beneath the dorsal fin is a dense, barrel-shaped torso. Its enormous skull is held up by its long neck. A long slender snout resembles that of a crocodile, and its short hind limbs are disproportionate to its dense and powerful forelimbs.
“Spinosaurus is incredibly front heavy,” paleontologist Paul Sereno tells National Geographic. Serena, Ibrahim’s postdoctoral adviser at the University of Chicago, also discovered several notable North African dinosaurs, including Suchomimus, a relative of Spinosaurus with long, crocodile-like jaws. “It’s like a cross between an alligator and a sloth.”
The animal was originally discovered and named by Ernst Freiherr Stromer von Reichenbach between 1910 and 1914. Fossils of Stromer’s Spinosaurus were displayed in Munich’s Bavarian State Collection for Paleontology and Geology. But, in April 1944, a World War II Allied air raid destroyed the museum. Unfortunately, all that was left of the Spinosaurus was Stromer’s field notes, in which, according to National Geographic, he had concluded that the animal was “highly specialized.” But specialized for what was a question that remained unanswered.
It was previously thought that while most dinosaurs might have had the ability to swim at some capacity, they were predominantly land animals. No one imagined dinosaurs swimming alongside crocodile and large fish—until March 2013.
After a long journey and hard search, Ibrahim was brought to a place in Morocco whose surrounding cliffs proved huge rivers had flowed 100 million years ago. And there they were– the Spinosaurus fossils Ibrahim had been searching for.
According to National Geographic, after piecing together the bones with CT scans and digital reconstruction software, the paleontologists “wrapped the skeleton in digital skin to create a dynamic model of the animal’s center of gravity and how it moved. Their analysis lead to a remarkable conclusion: Unlike all other predatory dinosaurs, which walked on their hind legs, Spinosaurus may have been a functional quadruped, also enlisting its heavily clawed forelimbs to walk.”
This finding encouraged Ibrahim and his team to view the Spinosaurus as an animal spending its days in water rather than on land. With that perspective, the rediscovered dinosaur began to make more sense.
National Geographic explains that the placement of the nostrils would have allowed the animal to breathe while its head was submerged. The barrel-shaped torso was similar to that of dolphins and whales. While the disproportionate hind legs wouldn’t be ideal for walking, they would have been perfect for paddling. It’s long, croc-like jaws and teeth would have been a great tool snacking on a large fish.
While it is still believed that many dinosaurs spent time in nearby rivers and lakes, Ibrahim believes the Spinosaurus would have spent about 80 percent of its time immersed in water. This belief makes the Spinosaurus the first of its kind. That is until the next dino-mite discovery!
Photo credit: National Geographic