The fossil tail suggests the Spinosaurus aegyptiacus could swim, a departure from the commonly-held belief non-avian dinosaurs could not swim.
Rabat – German-Moroccan paleontologist Nizar Ibrahim has published new evidence that spinosaurid dinosaurs could swim, a controversial theory, by using their tails to propel them through water.
Studying the fossil of a “Spinosaurus aegyptiacus” tail researchers found in eastern Morocco, Ibrahim concluded the tail was “unambiguous evidence” of the ability to swim.
Along with his co-authors, Ibrahim argued in a Nature paper on April 29 “the tail shape of Spinosaurus produces greater thrust and efficiency in water than the tail shapes of terrestrial dinosaurs.”
Among paleontologists, the question of whether dinosaurs were able to swim has been controversial. Ibrahim has hypothesized for years that spinosauruses could swim because they had dense bones, paddle-like feet, and heads suitable for catching fish.
Ibrahim’s hypothesis was comparatively unique among the paleontologist community, where “historical proposals that some groups [of dinosaurs] lived in aquatic environments were abandoned decades ago.”
In a 2015 TED talk, Ibrahim explained how he came to Morocco “on a quest to uncover new remains of a bizarre, giant, predatory dinosaur called spinosaurus.”
As the name “Spinosaurus aegyptiacus” implies, the first person to record the animal’s fossils, Ernst Stromer, found them in Egypt. The fossils Stromer found and reported in 1915 were later destroyed in World War II.
During extensive excavations in the Kem Kem Beds in Eastern Morocco, Ibrahim found various dinosaur fossils but at first, “spinosaurus itself proved to be very illusive.”
However, after locating a local fossil hunter’s dig site, the team found some spinosaurus bones.
Especially after reconstructing the bones into a digital skeleton by CT-scanning them, Ibrahim believed he was looking at a “river monster.”
“When we looked at the digital skeleton, we realized that yes, this was a dinosaur unlike any other,” he said, explaining how its features pointed to its water environment.
Although the Sahara is dry today, researchers believe it was a large river system in the Cretaceous period.
Ibrahim encouraged further exploration, saying “I think the Sahara is still full of treasures.”
National Geographic named Nizar Ibrahim an “Emerging Explorer” in 2014.