CNN —
A newly identified dinosaur species, Spinosaurus mirabilis, has been discovered in Niger, boasting a prominent bony crest and dating back approximately 95 million years. This marks the first new Spinosaurus species identified in over a century.
The findings, published February 19 in the journal Science, suggest the prehistoric creature is a close relative of Spinosaurus aegyptiacus, a giant, fish-eating dinosaur characterized by a sail along its back, first described in 1915 by German paleontologist Ernst Stromer von Reichenbach.
This discovery could resolve a long-standing debate among scientists regarding Spinosaurus species: were they marine pursuit predators—animals that dove and swam after prey—or more akin to herons, wading along the shoreline and strategically attacking fish in shallow waters? The ongoing research into these apex predators highlights the complex interplay between anatomy, environment, and predatory behavior.
Paul Sereno, the study’s lead author and a Professor of Organismal Biology and Anatomy at the University of Chicago, explained that the new research points to Spinosaurus being what he calls a “hell heron”—a semi-aquatic shoreline hunter with physical similarities to a wading bird, but on a terrifying scale.
According to the newly identified fossils, the creature likely possessed a long, narrow snout for catching fish, a neck capable of thrusting its head forward in a striking motion, and legs long enough to hunt in shallow waters. This anatomical profile suggests a highly specialized predator adapted to a unique ecological niche.
Researchers compared the proportions of the fossilized bones—head, neck, and hind limbs—to those of an adult great blue heron, revealing striking similarities that suggest Spinosaurus was adapted for stalking and attacking along open shorelines and riverbanks.
But the “definitive proof,” according to Sereno, was the fossils’ location far inland, indicating the creature lived and hunted along river systems and other shallow waterways, rather than the sea. Finding a giant marine-adapted predator in the center of the continent, he said, would be as improbable as “finding a blue whale in Chicago.”
Like Spinosaurus aegyptiacus, Spinosaurus mirabilis featured a bony crest on its head, but in S. Mirabilis the structure was more pronounced and dramatic compared to its relatives.
“It’s a showy bony crest projecting off the head, like Elvis’s pompadour,” Steve Brusatte, a paleontologist at the University of Edinburgh, commented in an email. He was not involved in the study.
“It’s a terrible weapon,” Sereno said of the creature’s head crest.
It’s awkwardly positioned, fragile, and asymmetrical—traits that suggest it wasn’t used for combat but for display and signaling, perhaps even sexual signaling, he added.
The difference in the head crests of the newly identified fossils and other Spinosaurus remains helped researchers confirm that it was a distinct species within the Spinosaurus genus.
Compared to Spinosaurus aegyptiacus, Spinosaurus mirabilis similarly had a lower jaw and interlocking teeth, a configuration Sereno said is well-suited for gripping slippery fish.
The study also sheds light on the evolution of Spinosaurus, which may have developed in three phases. During the Jurassic period, its skull emerged for fish-catching; in the early Cretaceous, Spinosaurus became a dominant predator around the ancient Tethys Sea; and just before the late Cretaceous, as the Atlantic Ocean opened, Spinosaurus reached its largest sizes and became an ambush specialist in shallow waters in North Africa and South America.
“It’s been a long-enigmatic dinosaur, but with each new fossil find the true Spinosaurus is slowly taking shape,” Brusatte said.
Sereno emphasized how modern tools accelerated the research. The team took hundreds of photos and created 3D models of S. Mirabilis, allowing researchers to digitally manipulate the crest and jaw fragments, and begin reconstructing the skull.
The new fossil find represents a “renaissance” in research on giant predatory dinosaurs, commented Matteo Fabbri, an assistant professor at the Center for Functional Anatomy and Evolution at Johns Hopkins University School of Medicine, in an email. Fabbri was not involved in the research.
He also noted that it’s difficult to establish a new species from fragmented fossils. The fragmentary nature of the fossils doesn’t offer “much to work with, leaving many questions about the animal’s true anatomy,” he said.
A replica of the Spinosaurus skull is on display at the Children’s Museum in Chicago, offering children an opportunity to view it.
For Sereno, the fossils are not only an crucial scientific find, but an invitation for the next generation to engage with the wonder of discovery.
