For over a century, the Spinosaurus family had one well-known member. Now it has two — and the newcomer has a horn.
Paleontologists from the University of Chicago, leading an international team, have announced the discovery of a new Spinosaurus species: Spinosaurus mirabilis. The find, published in the journal Science, marks the first new Spinosaurus species discovered in more than 100 years — and adds a striking new chapter to one of prehistoric life's most fascinating lineages.
The fossils were unearthed at the Jenguebi dig site in Niger, in the central Sahara. The area sits on what would have been, 95 million years ago during the Cretaceous period, a vast river-threaded floodplain teeming with life. Spinosaurus mirabilis was built to live there — semi-aquatic, hunting enormous fish in the shallows, wading through waters that were still relatively shallow by modern standards.
Lead researcher Paul Sereno described the animal's lifestyle in evocative terms. "I suspect this animal was fishing largely in about 3 feet of water," he told NPR, "although it was large enough to stand in about 6 feet without floating." In those Cretaceous rivers, prey was not in short supply — fossil evidence suggests fish of 9 feet or more swam in the same waters.
The new species was roughly the length of a school bus. But its most distinctive feature is what sits on top of its skull: a pronounced bony horn, clearly visible when comparing skull casts of Spinosaurus mirabilis and its previously known cousin, Spinosaurus aegyptiacus. No previous Spinosaurus fossil had shown anything quite like it.
Sereno compared the animals to modern herons — long-necked, patiently predatory, perfectly adapted to hunting in shallow water. The comparison conjures something wonderful: a heron the size of a bus, wading through a Saharan river 95 million years ago, snatching fish that would dwarf anything swimming today.
For the paleontology community, discoveries like this are a reminder that the prehistoric world still has secrets to give up — buried under ancient sandstone, waiting to be found by people willing to dig in one of the world's most remote landscapes.
The first new Spinosaurus species in over a century. And it had a horn. Of course it had a horn. 🦕