New Spinosaurus Species with Striking Crest Discovered in Niger

A newly discovered fossil in Niger is reshaping our understanding of Spinosaurus, the largest known predatory dinosaur. Paleontologists have identified a new species, Spinosaurus mirabilis, distinguished by a striking, scimitar-shaped crest and offering fresh evidence in a long-standing debate about how these massive creatures hunted. The findings, published February 19 in the journal Science, suggest Spinosaurus wasn’t a deep-sea predator, but rather a “hell heron” – a semi-aquatic hunter stalking fish in shallow waterways.

A Distinct Crest and a New Species

The discovery marks the first new Spinosaurus species identified in over a century. Fossils of Spinosaurus mirabilis were excavated from outcrops of the Farak Formation in Niger during expeditions in 2000, 2019, and 2022, led by paleontologist Paul Sereno of the University of Chicago. The holotype specimen, designated MNBH JEN1, includes fragments of the skull – the right premaxilla, both maxillae, a nasal crest, and part of the dentary – along with five maxillary teeth. A second specimen, MNBH JEN2, yielded additional cranial and postcranial bones, including parts of vertebrae, the ischium, and the femur.

What immediately set S. Mirabilis apart was its prominent crest. Unlike the more subdued crest seen in the previously known Spinosaurus aegyptiacus, the crest of S. Mirabilis is larger and more dramatically shaped. Researchers believe the crest, textured with channels indicating it was covered in keratin (the same material as human fingernails), served a display function – perhaps for attracting mates – rather than for combat, given its fragility and asymmetrical structure. As University of Edinburgh paleontologist Steve Brusatte noted in an email, the crest resembles “the pompadour hairstyle of Elvis.”

From Marine Predator to Wading Hunter

For decades, paleontologists debated whether Spinosaurus was primarily a marine predator, actively pursuing prey in the ocean, or a more terrestrial hunter. The discovery of S. Mirabilis, coupled with detailed anatomical analysis, strongly supports the latter hypothesis. Sereno describes the dinosaur as a “hell heron,” drawing a parallel to modern wading birds.

The anatomical features of S. Mirabilis align with this interpretation. The fossil evidence suggests a long, narrow snout ideal for snatching fish, a neck capable of a rapid, stabbing motion, and legs long enough to wade in shallow water. Crucially, the fossils were found far inland, in what was once a vast river system, rather than in marine deposits. “Finding a giant predator adapted to a marine environment in the middle of the continent would be as improbable as finding a blue whale in Chicago,” Sereno explained.

Anatomy Tailored for a Specific Niche

Compared to Spinosaurus aegyptiacus, Spinosaurus mirabilis similarly possessed a lower jaw and interlocking teeth, an adaptation well-suited for securing slippery fish. Researchers used 3D modeling to digitally manipulate the fragmented crest and jaw pieces, reconstructing the skull and gaining a clearer understanding of the dinosaur’s anatomy. This process, facilitated by modern imaging techniques, has been instrumental in advancing the research.

The team compared the proportions of the head, neck, and hind limbs of S. Mirabilis to those of a great blue heron, revealing striking similarities in their skeletal structure and suggesting a similar hunting strategy – ambushing prey along shorelines and riverbanks. This contrasts sharply with earlier depictions of Spinosaurus as a fully aquatic predator.

A Three-Phase Evolutionary History

The study sheds light on the evolutionary trajectory of Spinosaurus, suggesting it developed in three distinct phases. The initial phase, during the Jurassic period, saw the evolution of a skull adapted for catching fish. In the early Cretaceous, Spinosaurus became a dominant predator around the ancient Tethys Sea. Finally, as the Atlantic Ocean began to open in the late Cretaceous, Spinosaurus reached its largest size and specialized as an ambush predator in the shallow waters of North Africa and South America.

Matteo Fabbri, a professor at Johns Hopkins University School of Medicine, described the discovery as a “renaissance” in research on giant predatory dinosaurs. However, he cautioned that the fragmentary nature of the fossils presents challenges. “The fragmentary nature of the fossils doesn’t offer much to work with, leaving many questions about the animal’s true anatomy,” he noted.

What Comes Next: Continued Research and Public Engagement

The discovery of Spinosaurus mirabilis isn’t the end of the story. Further research is needed to fully understand the species’ anatomy, behavior, and evolutionary relationships. The team plans to continue excavating in Niger, hoping to uncover more complete fossils. A replica of the Spinosaurus skull is currently on display at the Children’s Museum in Chicago, offering the public a chance to engage with this remarkable discovery. Sereno emphasizes that these fossils are not just a scientific breakthrough, but an opportunity to inspire the next generation of paleontologists and explorers. The ongoing analysis of the existing fossils, combined with future excavations, promises to further refine our understanding of this enigmatic dinosaur and its place in the prehistoric world. You can learn more about the Farak Formation and ongoing paleontological work in Niger through the University of Chicago’s project website.

Further insights into spinosaurid evolution can be found in Brusatte’s book, The Rise and Fall of the Dinosaurs (Simon & Schuster, 2023).