Paleontologists have discovered fossils of a new dinosaur species deep in the Sahara Desert, marking the first indisputable evidence of a new Spinosaurus species found in more than a century. The carnivorous dinosaur, named Spinosaurus mirabilis, meaning "astonishing" in Latin, was roughly the size of a Tyrannosaurus rex and roamed the earth approximately 95 million years ago.

Paul Sereno, a professor of organismal biology and anatomy at the University of Chicago who led the expedition, described the discovery as extraordinary. "It was the expedition of a century, without exaggeration," Sereno told ABC News. "It was an adventure and a half, never probably to be matched."

The expedition, conducted in 2022 at a remote site called Jenguebi in northern Niger, yielded 55 tons of specimens. Among the finds were jaw fragments, several teeth, and three scimitar-shaped head crests that distinguished this species from previously known Spinosaurus dinosaurs. According to research published Thursday in the journal Science, the crests were likely sheathed in keratin and brightly colored, potentially growing to a height of nearly 20 inches, making them the tallest cranial crest of any non-avian dinosaur.

The dinosaur's distinctive features included interlocking rows of teeth designed for catching slippery fish, an adaptation seen in many fish-eating predators. Sereno described Spinosaurus mirabilis as a "hell heron" that could wade into two meters of water but likely spent most of its time stalking shallower areas for large fish.

The discovery site at Jenguebi was located hundreds of miles inland from the nearest coastline, challenging previous theories that Spinosaurus species were primarily aquatic animals adapted for ocean environments

The fossils suggest the dinosaur inhabited a forested environment dissected by rivers, far from coastal areas. This finding provides new evidence about the geographic distribution of Spinosaurus species across Africa and South America during the Late Cretaceous period.

Sereno plans to display replicas of Spinosaurus mirabilis' skull and scimitar-shaped head crest at the Chicago Children's Museum beginning on March 1.

Mike Miller