Bold opener: A newly found giant predator wasn’t just a fish hunter; it was a towering marvel of the Cretaceous marsh, complete with a striking horns-and-crests feature that rewrites what we thought we knew about Spinosaurus.
But here’s where it gets controversial: this discovery challenges the long-held image of Spinosaurus as a fully aquatic giant, suggesting a creature that may have thrived in shallow, riverine habitats rather than deep seas. Now, let’s unpack what this means, piece by piece.
A newly identified dinosaur species roamed marshy inland areas, specialized in catching fish, and boasted an impressive horn projecting from its skull. This is the first new Spinosaurus species named in more than a century, a lineage recognized for its ancient fish-eating predatory habits dating back to the Jurassic period, over 140 million years ago.
The species, named Spinosaurus mirabilis, reached roughly the length of a school bus and was excavated in Niger by an international team led by researchers from the University of Chicago. The discovery is detailed in Science, published recently.
Researchers estimate that Spinosaurus mirabilis lived around 95 million years ago, during the mid-Cretaceous, in a marshy inland zone that lies in what is today the central Sahara.
Lead author Paul Sereno compared the animal to herons: both hunt fish in shallow waters and possess bodies well-suited to semi-aquatic life. In an NPR note, Sereno explained that the animal likely fished mostly in about 3 feet of water, though it was large enough to stand in roughly 6 feet of water without floating.
The rivers of Spinosaurus’ era teemed with large fish, some exceeding nine feet in length, which would have made a substantial meal for a predator of this size.
Skull casts from Spinosaurus mirabilis (new) and its previously known relative Spinosaurus aegyptiacus (old) reveal a prominent, foot-long curved horn on the new species. The researchers speculate the horn/crest could have been brightly colored, inferred from fossil texture, and may have served signaling or display functions to attract or communicate with other members of the species.
The expedition that yielded the crest fossil began in 2019; a follow-up dig in 2022 uncovered additional specimens at the same site, located in a remote sandy stretch of the Sahara.
It’s important to note that this region wasn’t a desert when Spinosaurus roamed there. In the mid-Cretaceous, rivers threaded through the landscape, even though the area lay hundreds of miles from the nearest ocean.
Spinosaurus researchers have long been curious about how aquatic these giants truly were. In 2020, paleontologist Nizar Ibrahim told NPR’s Short Wave that bones from Morocco hinted at a powerful swimmer within the Spinosaurus lineage, with a tail that resembled those of modern fully or largely aquatic species.
The new evidence, however, paints a more nuanced picture: Spinosaurus mirabilis might have thrived in relatively shallow waters and could have been less of an active diver than previously imagined. Sereno summed up the vision this way: like blue herons, it may have been a surface-level hunter that rarely, if ever, plunged underwater for its meals, adapting to a lifestyle that balanced land and water.
In short, this discovery expands our understanding of the Spinosaurus family, suggesting a species that could navigate marshy, inland waterways with a distinctive horned crest, while hunting fish in shallower waters than once thought. Which interpretation resonates more with you: a semi-aquatic ambush predator specialized for shallow rivers, or a broader, more versatile hunter capable of a wide range of aquatic or semi-aquatic habits? Share your thoughts in the comments.
