Scientists have discovered Spinosaurus mirabilis, a new species of spinosaurid dinosaur, in a remote area of Niger's Sahara. The find, led by Paul Sereno of the University of Chicago, features a striking scimitar-shaped crest and suggests these dinosaurs waded in inland rivers rather than being fully aquatic. The fossils, unearthed in 2019 and 2022, appear in a study published in Science.
In November 2019, paleontologists spotted a scimitar-shaped crest and jaw fragments on the surface of the central Sahara in Niger. It took until 2022, with a larger team, to uncover two more crests and confirm the discovery of Spinosaurus mirabilis, a previously unknown spinosaurid species. The research, involving a 20-member team led by Paul Sereno, PhD, Professor of Organismal Biology and Anatomy at the University of Chicago, was published in Science in 2026.
The dinosaur's most notable feature is its enormous crest, textured with blood vessel channels indicating it was covered in keratin and likely brightly colored, arching upward like a curved blade for display. The skull shows tightly interlocking upper and lower teeth, forming a trap for slippery prey, a trait seen in fish-eating animals but distinctive among dinosaurs in spinosaurs.
Unlike previous spinosaurid fossils from coastal sites, these remains come from inland river deposits 500-1000 km from ancient shorelines, alongside long-necked dinosaur skeletons in forested waterway sediments. This inland habitat challenges ideas of fully aquatic spinosaurs. "I envision this dinosaur as a kind of 'hell heron' that had no problem wading on its sturdy legs into two meters of water but probably spent most of its time stalking shallower traps for the many large fish of the day," Sereno said.
The expedition traced a 1950s note about a similar tooth, guided by a local Tuareg man to the site. "This find was so sudden and amazing, it was really emotional for our team," Sereno added, recalling the moment of digital reconstruction in the Sahara.
The discovery bolsters Niger's paleontological importance, with fossils prepared at the University of Chicago's lab and replicas heading to the Chicago Children's Museum exhibit starting March 1. Paleoartists created reconstructions, including a scene of the dinosaur over a coelacanth carcass, featured on Science's cover.