A groundbreaking discovery in Niger sheds light on ancient aquatic adaptations of a dinosaur species, challenging previous assumptions about spinosaurids.
A newly discovered dinosaur species, Spinosaurus mirabilis, has been identified as a large, semi-aquatic predator that hunted fish in shallow waterways during the Cretaceous period. The find, announced in a Science journal paper, marks the first major spinosaurid discovery in over a century and provides new insights into the evolutionary adaptations of these enigmatic theropods. The dinosaur, unearthed in Niger, is distinguished by a prominent cranial crest and specialized anatomy suited for an aquatic lifestyle.
The Spinosaurus mirabilis fossils were discovered in a remote desert region of Niger, approximately 500–1,000 kilometers inland from ancient coastlines. The site, part of the Jenguebi dig area, was initially explored in 2019 by a team led by paleontologist Paul Sereno of the University of Chicago. Subsequent excavations in 2022 uncovered additional specimens, including a foot-long curved horn-like structure on the skull. This feature, described as a ‘sabre-like’ crest, is distinct from the horns of ceratopsian dinosaurs like Triceratops and instead suggests a role in display or communication.
The new species, estimated to have lived 95 million years ago, was comparable in size to a school bus, with a long, low skull adapted for catching fish. Its conical teeth, arranged in a spoon-shaped jaw, were ideal for gripping slippery prey. The dinosaur’s extended hind limbs and retracted nostrils indicate a semi-aquatic existence, similar to modern crocodiles. Paleontologist Sereno likened the animal to a ‘hell heron,’ wading in shallow waters to ambush fish. The crest, likely brightly colored or keratin-covered, may have played a role in social interactions or species recognition.
The discovery challenges previous assumptions about Spinosauridae“>spinosaurids[/highlight], which were once thought to be strictly coastal or aquatic. Spinosaurus mirabilis was found in a riverine habitat, hundreds of miles from the nearest ocean, suggesting these dinosaurs were more adaptable to inland environments. This aligns with earlier findings, such as the 2020 study of Spinosaurus aegyptiacus fossils in Morocco, which revealed adaptations for swimming, including a deep, tail-like structure potentially used for propulsion.
The Spinosaurus mirabilis belongs to the spinosaurid family, a group of large theropod dinosaurs characterized by their crocodilian skulls and bony crests. The family Spinosauridae, which includes Spinosaurus, Sigilmassasaurus, and others, is believed to have thrived during the Early to Late Cretaceous. While some spinosaurs were semi-aquatic, others may have been terrestrial, highlighting the diversity within the group. The new species adds to the debate over whether spinosaurs were fully aquatic or simply adapted to water-based hunting.
The Niger discovery was the result of an international collaboration between the University of Chicago and other institutions. The team’s work underscores the importance of remote desert regions in uncovering dinosaur fossils, as these areas often preserve delicate skeletal remains. Further research will focus on analyzing the crest’s structure and determining its exact function, as well as comparing ”Spinosaurus
