"Celebrating the Richness of Paleontology through Fossil Hunting"
Paleoartist rendering of Spinosaurus mirabilis eating a coelacanth. Art by Dani Navarro.
Paleontology News
New Spinosaurus Species Discovered in the Sahara: Spinosaurus mirabilis
Scientists have discovered Spinosaurus mirabilis, a new Late Cretaceous species from Niger. The scimitar-crested spinosaurid lived in inland river systems of the Sahara and refines our understanding of spinosaur evolution.
Paul Sereno poses with reconstructed skull of Spinosaurus mirabilis. Photograph by Keith Ladzinski. From: University of Chicago.
Spinosaurus mirabilis is a newly discovered species of spinosaurid dinosaur from the Late Cretaceous of Niger in the Sahara Desert. Dating to about 95 million years ago, it had a distinctive scimitar-shaped crest and specialized fish-catching teeth, supporting evidence that some Spinosaurus species lived in inland river environments.
New Species: Spinosaurus mirabilis is the first new species of Spinosaurus described in over 100 years.
Age:
Lived about 95 million years ago during the Cenomanian Stage of the Late Cretaceous.
Discovery Location:
Found in the Farak Formation of central Niger in the Sahara Desert.
Distinctive Feature:
Possessed a large, scimitar-shaped cranial crest likely covered in keratin in life.
Diet:
A fish-eating (piscivorous) predator with elongated jaws and interlocking conical teeth for gripping slippery prey.
Scientific Importance:
The inland fossil site supports the idea that some Spinosaurus species were semi-aquatic river hunters rather than fully marine swimmers.
Video: Fossil hunting for the new Spinosaurus in Niger with Paul Sereno
Named Spinosaurus mirabilis, this newly described species of fish-eating theropod is distinguished by a dramatic scimitar-shaped cranial crest and fossil remains recovered far inland in Niger, well away from ancient coastal environments. The discovery was published in Science by a team led by Paul C. Sereno and colleagues, and represents the first new species of Spinosaurus described in more than a century. Prior to this work, the only widely accepted species in the genus was Spinosaurus aegyptiacus which is known from deposits in North Africa.
A “Scimitar-Crested” Spinosaurus
The most striking feature of Spinosaurus mirabilis is its enormous blade-like crest rising from the skull. When the first crest fragment was discovered in 2019 in Niger’s central Sahara, researchers initially didn’t recognize what they had found. Only after a return expedition in 2022 uncovered additional crest material—and a 3D digital reconstruction of the skull assembled in camp using solar-powered equipment—did the significance become clear.
The crest shows evidence of internal vascular canals and surface texture indicating it was sheathed in keratin in life. Researchers believe it was likely brightly colored and curved upward like a saber-shaped beacon—possibly used for visual display.
This hypertrophied nasal-prefrontal crest clearly separates S. mirabilis from its close relative, Spinosaurus aegyptiacus.
A Deadly Fish-Eater with Interlocking Teeth
Like other spinosaurids, Spinosaurus mirabilis was a specialized fish-eating predator. Its elongated snout housed interdigitating teeth—an unusual arrangement in which lower jaw teeth protrude between upper teeth, forming a trap for slippery prey.
This adaptation is seen in other aquatic or semi-aquatic predators such as ichthyosaurs, crocodilians, and some pterosaurs. Among dinosaurs, however, it is distinctive to spinosaurids.
The new species also shows subtle differences in snout shape and tooth spacing compared to S. aegyptiacus, reinforcing its status as a distinct species rather than simple variation.
Far from the Sea: An Inland Habitat
Previous Spinosaurus fossils were primarily discovered in coastal marine deposits near ancient shorelines, fueling debate about whether these giant theropods were fully aquatic swimmers or shoreline ambush predators.
However, S. mirabilis was unearthed at Jenguebi in Niger, in sediments of the Farak Formation dating to the Cenomanian Stage of the Late Cretaceous, approximately 95 million years ago. The site lies roughly 500–1000 kilometers from the nearest ancient marine shoreline.
The fossils were buried in fluvial (river) sediments alongside partial skeletons of long-necked sauropods, suggesting a forested inland riparian habitat dissected by rivers.
Rather than a fully aquatic diver, this evidence supports the interpretation of Spinosaurus as a wading predator—more like a giant “hell heron” stalking river shallows for large fish.
The Evolution of Spinosaurids
The discovery of Spinosaurus mirabilis adds an important piece to the evolutionary puzzle of spinosaurids.
A time-calibrated phylogenetic analysis suggests three major phases in spinosaur evolution:
Jurassic origins – Development of elongated fish-snaring skulls and early divergence into baryonychines and spinosaurines.
Early Cretaceous radiation – Circum-Tethyan expansion, with spinosaurids dominating coastal ecosystems.
Late Cretaceous specialization – Maximum body size and shallow-water ambush adaptations, limited largely to northern Africa and South America.
The inland discovery of S. mirabilis strengthens the interpretation that late spinosaurines were shoreline and river-margin predators, not open-water pursuit swimmers.
A Remarkable Sahara Expedition
The path to discovery began with a single sentence in a 1950s geological monograph referencing a saber-shaped tooth in the Sahara. No one had revisited the site in over 70 years. After navigating deep into the sand seas with the help of a local Tuareg guide, researchers located the fossil field and uncovered teeth and jaw fragments of the new species.
Back in Chicago, the fossils were cleaned, CT scanned, and digitally reconstructed. Paleoartist Dani Navarro created a vivid reconstruction of Spinosaurus mirabilis battling over a coelacanth carcass, later animated by other artists for the cover of Science. The combination of fieldwork, CT imaging, digital modeling, and paleoart highlights how modern paleontology blends traditional excavation with advanced technology.
Why This Discovery is Important
The discovery of Spinosaurus mirabilis is significant for several reasons:
It is the first new species of Spinosaurus described in over 100 years.
It provides strong evidence that spinosaurids inhabited inland river systems far from marine shorelines.
It supports the interpretation of spinosaurines as semi-aquatic waders rather than fully aquatic divers.
It refines our understanding of Late Cretaceous ecosystems in northern Africa.
As debates about Spinosaurus biology continue, S. mirabilis adds critical new data to the discussion—reshaping how paleontologists reconstruct the lifestyle of one of the most unusual large theropods ever discovered.
With only a few hours to spend after discovering the remote fossil area Jenguebi in November of 2019, Spanish paleontologist
Dan Vidal hovers over a quickly gathered collection of fossils, which included the crest and jaw pieces of a new scimitar-
crested spinosaurid. Photo by Paul Sereno University of Chicago.
A single Spinosaurus mirabilis rears over a carcass of the coelacanth Mawsonia on the forested bank of a river some 95 million years ago in what is now the Sahara Desert in Niger. Artwork by Dani Navarro. From: University of Chicago.
Journal Articles:
Paul C. Sereno et al. ,Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation.Science391,eadx5486(2026). DOI:10.1126/science.adx5486
Featuring striking illustrations and the latest science, this book explores how new fossils and modern technology are changing what we know about dinosaurs, with easy-to-read species overviews and vivid paleoart.
This excellent, up-to-date dinosaur book shows how discoveries from the last 20 years have transformed our understanding of dinosaurs, with short, accessible chapters on color, speed, bite force, parenting, and more.
Fun, creative, and educational! Build six wooden dinosaurs with your child and enjoy quality time together. Smooth, safe pieces fit perfectly to create adorable 3D models that spark imagination. A perfect birthday or holiday gift for little dinosaur fans.
What is Spinosaurus mirabilis? Spinosaurus mirabilis is a newly described species of spinosaurid dinosaur from the Late Cretaceous (Cenomanian) of Niger in the Sahara Desert. It is distinguished by a large scimitar-shaped cranial crest and adaptations for a fish-eating lifestyle.
How is Spinosaurus mirabilis different from Spinosaurus aegyptiacus? Spinosaurus mirabilis differs from Spinosaurus aegyptiacus in skull structure, crest morphology, and subtle variations in tooth spacing and snout proportions. The enlarged blade-like crest is one of the most distinctive features separating the two species.
Where was Spinosaurus mirabilis discovered?
Fossils of Spinosaurus mirabilis were discovered in the Farak Formation of central Niger in the Sahara Desert. The site represents inland river deposits dating to approximately 95 million years ago during the Cenomanian Stage of the Late Cretaceous.
Did Spinosaurus mirabilis live in water?
Evidence suggests Spinosaurus mirabilis lived in riverine environments and likely hunted in shallow water. The inland fossil location supports the interpretation of spinosaurids as semi-aquatic wading predators rather than fully aquatic swimmers.
What did Spinosaurus mirabilis eat? Spinosaurus mirabilis was primarily piscivorous, meaning it fed on fish. Its elongated snout and interlocking conical teeth were adapted for gripping slippery prey such as large freshwater fish.
Why is the discovery of Spinosaurus mirabilis important?
The discovery of Spinosaurus mirabilis is important because it represents the first new species of Spinosaurus described in over a century. It expands our understanding of spinosaur diversity, habitat preferences, and the evolution of large theropod dinosaurs in the Late Cretaceous of Africa.
Fossilguy.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising
fees by advertising and linking to amazon.com
