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| Spinosaurus the Spine Lizard of the Cretaceous |
Spinosaurus (meaning "spine lizard") is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian in the Late Cretaceous— 99 to 93.5 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 best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon.
In 2014, Ibrahim and his colleagues suggested that Spinosaurus aegyptiacus could reach over 15 metres (49 ft) in length. In 2022, however, Paul Sereno and his colleagues suggested that Spinosaurus aegyptiacus reached a maximum body length of 14 metres (46 ft) and a maximum body mass of 7.4 metric tons (8.2 short tons) by constructing an adult flesh model "with the axial column in neutral pose."
Spinosaurus is the longest known terrestrial carnivore; other large carnivores comparable to Spinosaurus include theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus. The most recent study suggests that previous body size estimates are overestimated, and that S. aegyptiacus reached 14 metres (46 ft) in length and 7.4 metric tons (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 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 (or backbones), grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some have suggested that the spines were covered in fat to form hump.
