Now, the researchers report the crest belonged to an entirely new species—Spinosaurus mirabilis—that roamed the area’s ancient river ecosystem some 95 million years ago in the Late Cretaceous. They published their discovery Thursday in Science. The new species adds to a heated debate over how these puzzling (and popular) dinosaurs lived and hunted in water.
This cast of Spinosaurus mirabilis shows how similar it was to that of its close relative Spinosaurus aegyptiacus. Unlike most theropod dinosaurs which had underbites, both animals had interdigitating teeth, meaning the upper and lower sets slide between each other and poke out of the jaw. Keith Ladzinski
A Saharan Spinosaurus
Today, Jenguebi is dry and barren, with few trees and endless sand. The local Tuareg community calls the area where the fossils were found Sirig Taghat, which translates to “No water, no goat.”
Sereno was drawn to the Sahara because of a report by French geologist Hugues Faure in the 1950s of a dinosaur tooth he found in Niger and wanted to search for similar sites.
“I knew it was the needle in the haystack,” Sereno says of the remote fossil site. “It could easily have been swallowed by the sand.”
Led by a local guide named Abdul Nasser riding on a moped across the desert, Sereno and Vidal first scouted the site in 2019 and found a Spinosaurus jawbone, along with a handful of other fossils. After returning in 2022, they ultimately identified bones from three S. mirabilis individuals, along with another predatory dinosaur named Carcharodontosaurus, two long-necked sauropod dinosaurs, crocodiles, turtles, and a freshwater fish species that could reach 12 feet long.
