Research reviewed 30 July 2026. Scientific interpretations may change as new evidence is published.
Spinosaurus was a huge meat eating dinosaur with a long crocodile like snout, a tall back sail and several features suited to life around water. Fossils strongly suggest that it ate fish, but scientists still debate whether it chased prey while swimming or hunted mainly in shallow water.
| Fact | Evidence based answer |
|---|---|
| Scientific name | Spinosaurus aegyptiacus |
| Time period | Late Cretaceous, about 99 to 94 million years ago |
| Fossil locations | Mainly Egypt and Morocco in North Africa |
| Diet | Carnivore, with strong evidence for fish eating |
| Estimated length | Around 14 metres, although estimates vary |
| Estimated mass | Perhaps 6 to 8 tonnes, with considerable uncertainty |
| Famous features | Long snout, conical teeth, tall sail and deep tail |
Spinosaurus was a theropod related to other two legged predatory dinosaurs. It belonged to a specialised family called the spinosaurids, whose members had long jaws, cone shaped teeth and enlarged claws.
The name Spinosaurus means "spine lizard". Tall bones rising from its backbone supported a sail or ridge. It was among the longest known predatory dinosaurs, but its unusual shape makes its mass difficult to calculate.
The first important skeleton was described in 1915, but the original bones were destroyed during the Second World War. Later Moroccan discoveries revealed more detail and raised fresh questions about movement.
Spinosaurus lived during the Late Cretaceous Period, about 99 to 94 million years ago. Its North African habitat contained rivers, tidal channels, mudflats and coastal areas.
These waters supported enormous fish, turtles and crocodile relatives. This rich environment could support a predator specialising in water based prey.
Its long, narrow skull carried conical teeth suited to gripping slippery prey. Nostrils farther back on the snout may have let the jaw tip enter water while the animal breathed.
Its unusually dense bones could have helped control buoyancy. A fossil described in 2020 revealed a tall, flexible, paddle shaped tail. Model experiments found that it pushed water more effectively than the narrow tails of typical land dinosaurs.
Spinosaurus had short hind limbs and broad feet. Some studies support active swimming. Others argue that its body created too much drag for fast underwater pursuit and that it may have hunted in shallow water instead.
Spinosaurus was a carnivore. Its jaws and teeth resemble those of fish catchers, while chemical evidence from fossil teeth suggests frequent contact with water.
Fish were probably important food, but Spinosaurus was unlikely to reject other opportunities. It may have eaten stranded animals, small dinosaurs or carrion when available. Scientists should therefore describe it as a fish specialist, not as an animal that ate nothing else.
Spinosaurus is known from incomplete fossils, including skull parts, teeth, vertebrae, ribs, limbs, feet and tail bones. Researchers compare them with related spinosaurids, but borrowed features require caution.
Drawings, measurements and photographs document the lost Egyptian specimen, but researchers cannot examine it with new equipment. Moroccan fossils have supplied crucial details, especially the deep tail and shortened legs.
Some fossils from the Kem Kem region lack precise location records. Careful fieldwork matters because surrounding rocks reveal age and habitat.
The biggest question is how Spinosaurus used water. It may have chased prey underwater, hunted while wading, or used several methods depending on depth and prey.
Researchers also debate its proportions, mass and balance because missing parts require estimation. New fossils could change the reconstruction.
The sail may have aided display, recognition, heat control or fat storage. No explanation is proved.
Spinosaurus was not a larger Tyrannosaurus. Its skull, limbs, tail and hunting style were different.
Its sail was not a swimming fin. The deep tail was better placed to produce thrust.
Scientists have not proved that it always swam. How it divided time between land, shallows and deeper water remains uncertain.
It may have been the longest known predatory dinosaur, at around 14 metres. Its exact mass is uncertain, so "biggest" depends on whether length or weight is being compared.
Yes. Its conical teeth, narrow jaws and other fossil evidence support fish eating as an important part of its diet. Chemical studies also indicate frequent contact with water.
It almost certainly could enter and move through water. Scientists disagree about whether it could efficiently chase prey underwater.
No one knows for certain. Display, recognition, heat control and energy storage have all been suggested.
The deep tail could push against water and probably helped with swimming. It may also have assisted with balance and display.
Some early reconstructions showed this, but the hand bones were not built for ordinary weight bearing. Its exact land posture is still studied.
The best known remains come from Cretaceous rocks in Egypt and Morocco in North Africa.
New fossils have revealed body parts that were previously unknown. Scientists update reconstructions when stronger evidence becomes available.
