Spinosaurus

Spinosaurus (; lit. 'spine lizard') is a genus of large spinosaurid theropod dinosaurs that lived in what is now North Africa during the Cenomanian age of the Late Cretaceous period, about 100 to 94 million years ago. The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material came to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The type species, S. aegyptiacus, is mainly known from the Bahariya Formation in Egypt and the Kem Kem beds in Morocco. The other species, S. mirabilis, is known from the Farak Formation in Niger. Possible junior synonyms include Sigilmassasaurus and the dubious S. maroccanus from the Kem Kem beds and Oxalaia from the Alcântara Formation in Brazil, though the distinction and validity of these taxa have been debated. Spinosaurus is among the largest known terrestrial carnivores; other large carnivores comparable to Spinosaurus include theropods such as Tyrannosaurus, Giganotosaurus and the contemporary Carcharodontosaurus. A 2022 study suggests that S. aegyptiacus could have reached 14 m (46 ft) in length and 7.4 t (8.2 short tons) in body mass. The skull of Spinosaurus was long, low, and narrow, similar to that of a modern crocodilian, and bore straight conical teeth with few to no serrations. It would have had large, robust forelimbs bearing three-fingered hands, with an enlarged claw on the first digit. The distinctive neural spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 m (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure. The hip bones of Spinosaurus were reduced, and the...