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Species Profile

Spinosaurus

Spinosaurus

Sail-backed hunter of ancient rivers
Daniel Eskridge/Shutterstock.com

Spinosaurus Distribution

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Size Comparison

Human 5'8"
Spinosaurus 16 ft 5 in

Spinosaurus is 2.9x the height of an average human.

Spinosaurus was semi-aquatic dinosaur from the Cretaceous period.

At a Glance

Genus Overview This page covers the Spinosaurus genus as a group. Stats below are general traits shared across the genus.
Also Known As Spine lizard, Spined lizard, Spino, Spinosaur
Diet Carnivore
Activity Cathemeral+
Lifespan 30 years
Weight 11000 lbs
Status Not Evaluated
Did You Know?

The genus name Spinosaurus means "spine lizard," referencing the tall neural spines that formed a back sail or ridge.

Scientific Classification

Genus Overview "Spinosaurus" is not a single species but represents an entire genus containing multiple species.

Spinosaurus is a genus of very large spinosaurid theropod dinosaurs from the mid-Cretaceous of North Africa, famous for its elongated crocodile-like snout, conical teeth, and tall neural spines forming a dorsal “sail.” It is commonly reconstructed as at least partly semi-aquatic, with many finds suggesting frequent use of riverine or coastal environments.

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Saurischia
Family
Spinosauridae
Genus
Spinosaurus

Distinguishing Features

  • Elongated, narrow rostrum with conical (less blade-like) teeth suited to gripping prey
  • Tall dorsal neural spines forming a prominent back sail/crest
  • Robust forelimbs with large claws
  • Cranial and skeletal traits consistent with spinosaurid theropods; often discussed as semi-aquatic based on anatomy and depositional context

Physical Measurements

Height
16 ft 5 in (13 ft 1 in – 19 ft 8 in)
Length
52 ft 6 in (45 ft 11 in – 59 ft 1 in)
Weight
9.4 tons (6.6 tons – 12.1 tons)
Tail Length
24 ft 7 in (19 ft 8 in – 29 ft 6 in)
Top Speed
16 mph
running

Appearance

Primary Colors
Secondary Colors
Skin Type Reptilian, crocodile-like scalation with small, non-overlapping scales; sparse direct skin evidence, so texture and presence of larger scutes/keratin coverings may have varied.
Distinctive Features
  • Very large theropod genus; size estimates vary widely due to fragmentary, debated material.
  • Estimated adult length broadly ~12-18+ m across proposed species assignments; extremes uncertain.
  • Estimated mass broadly several thousand kilograms (~4,000-10,000+ kg), highly model-dependent and debated.
  • Tall dorsal neural spines forming a back sail/hump; relative height and outline likely variable.
  • Elongated, narrow, crocodile-like snout with conical, interlocking teeth for gripping slippery prey.
  • Nostrils set back on the snout; reinforced skull suited to aquatic/semiaquatic feeding.
  • Robust forelimbs with large manual claws; used in prey handling and possibly shoreline locomotion.
  • Tail in some specimens reconstructed as tall-spined and laterally compressed; swimming contribution debated.
  • Ecology generalized as riverine/coastal-associated predator, often interpreted as fish-focused but likely opportunistic.
  • Behavior likely included frequent water use (wading/swimming) with terrestrial movement; degree of aquatic specialization varies by reconstruction.
  • Geographic/temporal range: mid-Cretaceous North Africa; species boundaries and assignments remain contested.
  • Lifespan unknown; likely multi-decade (roughly ~20-40+ years) by large theropod comparison, uncertain.

Did You Know?

The genus name Spinosaurus means "spine lizard," referencing the tall neural spines that formed a back sail or ridge.

Spinosaurus is known from mid-Cretaceous North Africa (notably Egypt and Morocco), in deposits linked to river systems and coastal plains.

Its long, narrow snout and mostly conical, non-serrated teeth suit gripping slippery prey-often interpreted as a strong fish-eating signal.

The first described Spinosaurus fossils (from Egypt) were lost when the Munich collection was destroyed in World War II, making later finds crucial.

Reconstructions of Spinosaurus have changed dramatically over time-especially ideas about its posture, tail, and degree of aquatic adaptation.

Even within the genus, which named species are valid is debated; some material historically assigned to Spinosaurus may belong to other spinosaurids.

It's among the most iconic "weird theropods," often cited in discussions of dinosaur ecology beyond strictly land-based hunting.

Unique Adaptations

  • Dorsal sail/ridge: elongated neural spines along the back created a prominent profile; proposed functions include display, thermoregulation, species recognition, or a combination (no single function is confirmed).
  • Elongated, crocodile-like rostrum: narrow snout with forward-positioned nostrils compared to many theropods, consistent with feeding at the water's edge.
  • Conical teeth with reduced cutting edges: better for gripping and holding than slicing-useful for fish and other slippery prey.
  • Dense limb bones (reported in spinosaurids including Spinosaurus material): often interpreted as aiding buoyancy control in water, though how strongly this applied across all Spinosaurus individuals is debated.
  • Evidence used to argue for enhanced swimming (notably tail shape in some reconstructions): suggests stronger aquatic propulsion than typical large theropods, though details depend on which specimens truly belong within the genus.

Interesting Behaviors

  • Riverine/coastal association: commonly interpreted as spending substantial time near waterways, with feeding focused in aquatic or shoreline settings (degree of aquatic life may have varied among individuals/specimens).
  • Piscivory plus opportunism: likely frequently targeted fish, but may also have taken other prey or scavenged when available-generalist behavior is plausible given theropod ecology.
  • Ambush-style foraging: the long snout and tooth form suggest quick snapping and holding rather than slicing-well suited to lunging at prey in shallow water.
  • Niche partitioning: in North African ecosystems with multiple large predators, Spinosaurus is often hypothesized to have reduced competition by focusing more on aquatic food webs than strictly terrestrial prey (exact balance remains uncertain).

Cultural Significance

Spinosaurus, a giant theropod with a sail, often seen as semi-aquatic and fish-eating, changed dinosaur ideas. Discovered by Ernst Stromer in early 1900s Egypt, lost in war, then reshaped by later North African finds and media, showing how science changes and the Sahara's Cretaceous rivers.

Myths & Legends

"Spine lizard": the name Spinosaurus (coined in 1915) memorializes its defining feature-the towering back spines-turning anatomy into a lasting linguistic legend of the genus.

The lost Bavarian treasure: the original Spinosaurus aegyptiacus skeleton described by Ernst Stromer was destroyed during World War II in Munich, a real historical tale often retold as paleontology's great loss.

Stromer's Sahara expedition saga: early 20th-century fieldwork in Egypt's Western Desert-hard travel, dangerous conditions, and painstaking fossil recovery-became part of the genus's enduring human history.

Known from fragments, Spinosaurus lived in the public imagination for decades through drawings and partial bones. Later Moroccan finds sparked rediscovery and rebuilding, and debates over species and body shape continue.

Conservation Status

NE Not Evaluated

Has not yet been evaluated against the criteria.

Population Unknown

You might be looking for:

Spinosaurus aegyptiacus

75%

Spinosaurus aegyptiacus

Best-known and most widely accepted named species of Spinosaurus; described from Egypt; large semi-aquatic spinosaurid theropod.

Spinosaurus maroccanus

15%

Spinosaurus maroccanus

Contentious/uncertain species assignment (often treated as dubious or reassigned); reported from North Africa.

Spinosaurus sp.

10%

Spinosaurus sp.

Indeterminate Spinosaurus material from North Africa that cannot be confidently assigned to a single species.

Life Cycle

Birth 15 hatchlings
Lifespan 30 years

Lifespan

In the Wild
15–45 years

Reproduction

Mating System Data Deficient
Social Structure Solitary
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Across Spinosaurus, mating behavior is unknown from direct evidence; as a large theropod, it is commonly inferred to be mostly solitary with brief, seasonal pairings. Likely internal fertilization with egg-laying; no strong support for pair-bonds or cooperative care.

Behavior & Ecology

Social Family group Group: 1
Activity Cathemeral, Diurnal, Crepuscular
Diet Carnivore Large fish from riverine and deltaic/coastal systems

Temperament

Opportunistic forager with strong prey-focus
Territorial around prime shoreline or channel hunting areas
Risk-averse when not competing; avoids unnecessary injury
Aggressive during competition at carcasses or dense feeding sites (variable)

Communication

low-frequency booms or bellows Inferred for large theropods
hisses/snorts during close-range threat displays Inferred
short barks/grunts for close-contact signaling Inferred
visual display using dorsal sail posture and body orientation Hypothesized
head/neck postures and gape displays emphasizing long snout and teeth
tactile contact during courtship or parent-offspring interactions Speculative
water-surface splashing or wake-making as a close-range signal in aquatic settings Hypothesized

Habitat

Biomes:
Freshwater Wetland Marine Tropical Dry Forest Savanna
Terrain:
Riverine Coastal Plains Sandy Muddy
Elevation: Up to 3280 ft 10 in

Ecological Role

Large apex/near-apex predator in North African mid-Cretaceous riverine to coastal ecosystems, specializing toward aquatic prey while remaining opportunistically carnivorous

Regulation of fish and aquatic-vertebrate populations through predation Trophic coupling between aquatic and terrestrial food webs (moving nutrients/energy across habitat boundaries via feeding and carcass use) Scavenging/carcass processing that accelerates nutrient recycling and supports detrital food chains Shaping prey behavior and habitat use along waterways (predation pressure at river margins)

Diet Details

Main Prey:
Large freshwater and coastal fish Elasmobranchs Aquatic and semi-aquatic vertebrates Terrestrial vertebrate prey Carrion

Human Interaction

Domestication Status

Wild

Spinosaurus is an extinct genus (mid-Cretaceous, North Africa) and was never domesticated or managed by humans. All human interaction is indirect and modern-via fossil discovery, scientific study, museum display, media portrayals, and (illicit) fossil trade. Genus-level diversity is limited/uncertain because species boundaries and material attribution within Spinosaurus have been debated; reconstructions and ecological inferences vary accordingly.

As a Pet

Not Suitable as Pet

Legality: Not applicable as a live pet (extinct). Fossil ownership/collection laws vary by country and locality; unauthorized collecting/export/sale is often illegal. Any 'pet-like' ownership would only concern fossils or replicas, which may be regulated.

Care Level: Expert Only

Purchase Cost:
Lifetime Cost:

Economic Value

Uses:
Scientific research Museum and education Tourism and cultural heritage Entertainment/media licensing Commercial fossil preparation and casting Replica/merchandise market Illicit fossil trade (negative/illegal economic activity)
Products:
  • museum exhibits and traveling displays (casts/replicas)
  • academic publications, grants, and field programs tied to Spinosaurus research
  • documentaries, books, films, games, and related licensing
  • educational materials (curricula, models, outreach kits)
  • commercially produced casts, 3D prints, and reconstruction artwork
  • tourism draw for regional museums and fossil sites in North Africa
  • fossil preparation services and (where legal) regulated sales of legally collected specimens

Relationships

Predators 3

Carcharodontosaurus Carcharodontosaurus saharicus
Bahariasaurus Bahariasaurus ingens
Large crocodyliforms Elosuchus cherifiensis

Related Species 6

Spinosaurus
Spinosaurus Spinosaurus aegyptiacus Shared Genus
Spinosaurus
Spinosaurus Shared Genus
Baryonyx Baryonyx walkeri Shared Family
Suchomimus
Suchomimus Suchomimus tenerensis Shared Family
Irritator Irritator challengeri Shared Family
Sigilmassasaurus Sigilmassasaurus brevicollis Shared Family

Ecological Equivalents 4

Animals that fill a similar ecological role in their ecosystem

Large gharial-like crocodilians Gavialis gangeticus Has a long, narrow snout and specializes in fish-focused predation in river systems. Used as an ecological analogue for a primarily piscivorous shoreline/riverine hunter, though it is not a close relative.
Large riverine crocodyliforms Elosuchus cherifiensis Co-occurred in broadly similar fluvial and coastal settings and likely targeted overlapping prey (fish and aquatic/shoreline vertebrates), indicating niche overlap and competition pressures.
Semi-aquatic piscivorous theropods Suchomimus tenerensis Very similar feeding adaptations (conical teeth, elongated snout) and inferred river-edge foraging; illustrates convergent or near-convergent ecology within spinosaurids.
Large coastal and riverine fish-eating birds Pelecanus onocrotalus Not anatomically comparable overall. Useful as a modern ecological parallel for exploiting dense fish resources in shallow waters and along shorelines.

Types of Spinosaurus

3

Explore 3 recognized types of spinosaurus

Spinosaurus (type species) Spinosaurus aegyptiacus
Spinosaurus (proposed species; debated validity) Spinosaurus maroccanus
Spinosaurus (indeterminate species-level material) Spinosaurus sp.

A Spinosaurus lived around 90-100 million years ago during the Cretaceous period.

Their fossils were first discovered in Egypt by the Bavarian paleontologist Freiherr Ernst Stromer in 1912. It’s considered the largest known carnivore ever discovered and could reach lengths of 60 ft., which is the same size as a bowling lane or four cars parked behind each other.

Spinosaurus means “spine lizard” because of the sail (fin) on its back. Paleontologists have different theories about the fin’s function and much more, as not much is known about this gigantic dinosaur.

Incredible Spinosaurus Facts!

  • Spinosaurus is the biggest carnivorous dinosaur ever found
  • Scientists believe that the Spinosaurus mainly lived in water
  • The first Spinosaurus fossils ever found were destroyed during World War II

Description & Size

Spinosaurus is most notably known for its sail which was made up of protruding spinal spikes on its back. Their long, narrow skulls housed sharp teeth that resemble the modern-day crocodile. Other characteristics include:

  • Weighed up to 31,000lbs
  • Height of 23ft
  • Length between 45 to 60 feet

Their bite power measures 19,000 Newtons, and their huge crocodile-like jaws contained 64 conical teeth.

Theories About the Sail’s Function

Paleontologists have disagreed about the function of the fin on the Spinosaurus’s back. However, there are a few interesting theories worth considering.

Theory One

It might have acted as a form of protection. This theory may be a bit far-fetched because the Spinosaurus had no known threats or predators because of its size. However, scientists believe that when fully extended, the sail made them appear much larger, and as they were so big as is, this was extremely intimidating.

In addition, there is a possibility they used it to attract a mate. There is significant evidence that their spines were flexible, making it easy to arch their backs.

Theory Two

A second theory is that they used their sails to regulate their body temperature by storing any access fat or absorbing heat. Unfortunately, this theory is even less likely as their sails were made from bones with minimal blood vessels encased in tight skin.

Theory Three

The last theory is the fins were a bright color, similar to modern-day reptiles or amphibians. So, highlighting this massive structure with bright colors makes it a hard-to-ignore display structure.

However, it is possible that the fin had more than one function.

Spinosaurus and Deinonychus in the jungle. Spinosaurus is the largest terrestrial carnivore ever to roam the earth.

Spinosaurus and Deinonychus in the jungle. Spinosaurus is the largest terrestrial carnivore ever to roam the earth.

Diet – What Did the Spinosaurus Eat?

The Spinosaurus was a carnivore, but it preferred eating fish. Some of the species it preyed on were:

Some paleontologists believe that the Spinosaurus hunted in water because of its fin-like tail and webbed feet, which looked like large paddles.

There is a good chance that when it was on dry land, it walked on its two hind legs. This is due to the Spinosaurus’s long neck and trunk; it’s likely it had a forward-leaning center of gravity.

Habitat – When and Where It Lived

The Spinosaurus was first discovered in Egypt, but many researchers believe it originated in Western Europe. After the continents started to split, they migrated down to North Africa. Other countries where fossils were found include:

The Spinosaurus lived 90 to 100 million years ago during the Cretaceous Period and preferred swampy areas where they had abundant fish to eat.

Many paleontologists believe that the Spinosaurus spent the majority of its time in the water. Just like the early whales and other aquatic species, the Spinosaurus had:

  • Short hind legs and dense bones to help weigh it down in the water
  • Flat and wide claws and feet
  • A long snout similar to a crocodile
  • Conical teeth, which are an advantage for catching fish
  • Fin-like tail

Threats and Predators

The adult Spinosaurus was the largest carnivore of its time, making it unlikely to have many threats. However, their young developed in eggs and were probably the size of a small dog when hatching. So, it is probable that they were preyed on by predators in the area.

For example, the specimens found in North Africa likely had to protect their young from:

In addition, while still in the egg, they were vulnerable to:

Discoveries and Fossils – Where It was Found

A Bavarian paleontologist called Freiherr Ernst Stromer made a life-changing discovery in 1912. He discovered an unknown dinosaur with a gigantic jaw and five-foot spines, signaling that it had a sail or hump. He named it the Egyptian Spine Lizard, which translates into Spinosaurus.

However, the remains were destroyed by a Nazi supporter in 1944 during World War II because Stromer spoke out in public and criticized the Nazi party. So, unfortunately, the only surviving evidence is the detailed drawings and descriptions archived in Germany.

Other discoveries include:

The largest amount of Spinosaurus fossils was found in a cave outside Erfoud, Morrocco. With these bones, paleontologists finally had enough information to create the most defined Spinosaurus picture ever.

Extinction – When Did It Die Out?

The Spinosaurus roamed this earth during the Cenomanian and Albain ages over 90 million years ago. They died out 30 million years before the T-Rex showed up.

There’s a debate about how they perished. Some paleontologists believe a flood wiped them out, while others say it was a drought.

Similar Animals to the Spinosaurus

As the  Spinosaurus is thought to be the largest terrestrial carnivore ever to roam the earth, there is not much that can compare. However, there were a few theropods that came close:

  • Tyrannosaurus – A monstrous dinosaur weighing up to eight tons and stretched over 40ft. Their jaws were so powerful they could crush a car.
  • Giganotosaurus – Discovered in Argentina and Patagonia, this terrifying giant weighed 7-8 tons and measured 40-43ft in length. It was the first discovery of a dinosaur that could match the T-Rex.
  • Carcharodontosaurus – Named after the great white shark (Carcharodon) because of the similarities between their teeth. It matched, if not exceeded, the size of the T-Rex and Giganotosaurus.

Significance in Today’s Culture

The Spinosaurus made its debut in Jurassic Park III in 2001. It took center stage by killing the T-Rex within seconds by snapping its neck.

We next see the Spinosaurus in Jurassic World, where the T-Rex saves the day by crashing through a skeleton, culminating in an epic fight with the Spinosaurus.

In Jurassic World: Camp Cretaceous, we see a familiar antagonist return to our screens;  the spinosaurus from the third movie.

Besides the films, they are making appearances in:

  • Action figures
  • Video games
  • Books

In addition, Angola, Gambia, and Tanzania have honored this prehistoric beast by putting it on their postage stamps.

View all 391 animals that start with S

Sources

  1. Wikipedia / Accessed June 11, 2022
  2. Britannica / Accessed June 11, 2022
  3. The Dinosaur Database / Accessed June 11, 2022
  4. Fossil Guy / Accessed June 11, 2022
  5. a-z-animals / Accessed June 11, 2022
  6. Live Science / Accessed June 11, 2022
  7. Prehistoric Wildlife / Accessed June 11, 2022

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Spinosaurus FAQs (Frequently Asked Questions)

During the Cretaceous Period over 90-100 million years ago.