Fossils of huge ‘hell heron’ dinosaur unearthed in Niger
Researchers said its crest was likely intended for display, as it appears too fragile to have been used as a weapon, even though it was a solid bone without the air sacs found in some other dinosaur crests. The crest, probably sheathed in keratin like a bull’s horns, may have been brightly colored and played a role in sexual or territorial competition or recognition between individuals.
“It’s about love and life — attracting a mate, defending your warm shallows,” said University of Chicago paleontologist Paul Sereno, lead author of the research published Thursday in the journal Science. “What could be more important?”
The retracted location of its nostrils, further back than usual, allows it to submerge most of its snout underwater to stalk swimming prey for as long as necessary while still breathing normally. Additionally, its upper and lower rows of teeth fit together perfectly during a bite, called interdigitation.
“Their large conical teeth without interdigitated serrations form a very effective ‘fish trap’ for piercing and trapping slippery fish in the jaws, preventing them from slipping,” said paleontologist and study co-author Daniel Vidal of the University of Chicago and the Universidad Nacional de Educación a Distancia in Spain.
“Spinosaurus mirabilis has some of the most extreme piscivorous adaptations of any dinosaur, so we know it was better at preying on fish than it would have been at preying on other dinosaurs,” Vidal said.
Spinosaurus aegyptiacus fossils come from sites in Egypt and Morocco near the Cretaceous coastline of the Tethys Sea, the predecessor of today’s Mediterranean Sea and Indian Ocean. This fact, along with certain skeletal traits, has led some scientists to hypothesize that Spinosaurus was entirely aquatic, an open water swimmer and a diving pursuit predator in a marine environment.
But Spinosaurus mirabilis fossils were discovered far inland, about 300 to 600 miles from the nearest ocean shore. This fact, coupled with certain aspects of the animal’s anatomy, instead indicates that Spinosaurus is a shallow-water predator and not entirely aquatic, the researchers said.
Sereno called the discovery of Spinosaurus mirabilis “the death blow for the aquatic hypothesis.”
Jenguebi, where the fossils were discovered, is an isolated locality in the Sahara, with fossil-rich sandstone outcrops surrounded by sand dunes. For their 2022 expedition, the researchers set out from the city of Agadez in a convoy and drove off-road through desert terrain for nearly three days, often getting stuck in the sand.
The trip paid off, as they discovered parts of three skulls and other bones of Spinosaurus mirabilis, as well as fossils of other creatures.
Long eclipsed in the public imagination by the T. rex, the Spinosaurus is now having its moment in the spotlight.
“It’s a dinosaur event,” Sereno said.
