Spinosaurus, T. rex or Giganotosaurus? Meet the biggest carnivorous dinosaurs ever found, see them side by side, and find out who really wins.
Quick Answer
The biggest carnivorous dinosaur was Spinosaurus, about 46 feet (14 m) long, longer than a school bus. But Tyrannosaurus rex was probably heavier, at about 8 to 9 tonnes, and had a much stronger bite. Giganotosaurus was about the same size as T. rex.
All three giants were about as long as a school bus. Spinosaurus was the longest, but a lot of that length was its skinny snout and tail.
T. rex and Giganotosaurus were built like tanks, with huge heads and thick bodies. A grown-up would only come up to about the top of their legs!
Scientists don't agree on the exact numbers, because only a few skeletons of each have been found. A new fossil could change the ranking.
Every picture below uses the same scale, with a grown-up for comparison, so you can see how they measure up.
📏 Longest meat-eater
Say it: SPY-no-SORE-us
📏 Length: About 46 feet (14 m)
⚖️ Weight: About 7 tonnes, as heavy as an elephant
🗺️ 95 million years ago, North Africa
⭐ It had a tall sail on its back, a long snout like a crocodile, and a paddle-shaped tail. It spent lots of time in rivers catching giant fish. Its first fossils were destroyed in a bombing during World War II.
More dinosaurs that loved water →
💪 Heaviest meat-eater (probably)
Say it: tie-RAN-oh-SORE-us REX
📏 Length: About 40 feet (12.3 m)
⚖️ Weight: About 8 to 9 tonnes
🗺️ 68 to 66 million years ago, western North America
⭐ T. rex had the strongest bite of any land animal ever, strong enough to crunch through bone. Some of its teeth, roots and all, were as long as a banana. The biggest one ever found is nicknamed “Scotty.”
How we know T. rex was real →
🥈 T. rex's giant rival
Say it: JIG-ah-NOH-toe-SORE-us
📏 Length: About 40 to 43 feet (12 to 13 m)
⚖️ Weight: About 6 to 8 tonnes
🗺️ 98 million years ago, Argentina
⭐ Its name means “giant southern lizard.” It was found in 1993 by a car mechanic who hunted fossils for fun. It lived at the same time and place as giant long-necks, and may have hunted them.
🦈 Shark-toothed giant
Say it: kar-KAR-oh-DON-toe-SORE-us
📏 Length: About 40 feet (12 m)
⚖️ Weight: About 6 to 7 tonnes
🗺️ 95 million years ago, North Africa
⭐ Its name means “shark-toothed lizard,” because its flat, jagged teeth looked like a great white shark's. It lived in the same place as Spinosaurus. Spinosaurus caught fish while Carcharodontosaurus hunted on land.
🇺🇸 Big hunter of North America
Say it: AK-roh-KAN-tho-SORE-us
📏 Length: About 38 feet (11.5 m)
⚖️ Weight: About 5 to 6 tonnes
🗺️ 112 million years ago, Oklahoma and Texas, USA
⭐ It had a tall ridge of spines along its back, like a short sail. Giant three-toed footprints in Texas may have been made by Acrocanthosaurus walking along a beach.
More about dinosaur footprints →
🌏 T. rex's Asian cousin
Say it: TAR-bo-SORE-us
📏 Length: About 33 to 39 feet (10 to 12 m)
⚖️ Weight: About 4 to 5 tonnes
🗺️ 70 million years ago, Mongolia and China
⭐ A close cousin of T. rex that lived in Asia. Its arms were even tinier than T. rex's, compared to its body. Scientists have found lots of its skeletons, from babies to grown-ups.
🦴 Biggest Jurassic hunter
Say it: TOR-vo-SORE-us
📏 Length: About 33 feet (10 m)
⚖️ Weight: About 3 to 5 tonnes
🗺️ 150 million years ago, Portugal and Colorado, USA
⭐ Its name means “savage lizard.” It lived long before T. rex, at the same time as Stegosaurus and Brachiosaurus, and it is the biggest meat-eating dinosaur ever found in Europe.
🪶 Biggest raptor
Say it: YOO-tah-RAP-tor
📏 Length: About 18 to 23 feet (5.5 to 7 m)
⚖️ Weight: About as heavy as a polar bear
🗺️ 125 million years ago, Utah, USA
⭐ The biggest raptor ever found. It had feathers and a giant curved claw on each foot, about 9 inches long. The real Velociraptor was much smaller, about the size of a turkey!
Sizes are scientists' best estimates, and different studies give different numbers. 1 tonne is 1,000 kilograms, about 2,200 pounds.
| Spinosaurus | T. rex | |
|---|---|---|
| Longest | ✅ About 46 ft | About 40 ft |
| Heaviest | About 7 tonnes | ✅ About 8 to 9 tonnes |
| Strongest bite | Thin jaws for grabbing fish | ✅ Bone-crushing |
| Favorite food | Big fish | Big plant-eaters like Triceratops |
| Home | Rivers in North Africa | Forests and plains in North America |
| When it lived | 95 million years ago | 66 million years ago |
So who wins? Spinosaurus was the longest, but T. rex was the heaviest and strongest of the land hunters. They never met in real life: they lived about 30 million years apart, on different continents.
Not even close! The biggest dinosaurs of all were long-necked plant-eaters called titanosaurs. Argentinosaurus weighed about 70 tonnes, roughly 8 to 10 times more than a T. rex, and Patagotitan was about three times as long.
Giganotosaurus lived alongside giant long-necks in Argentina, and scientists think it may have hunted them, maybe by picking on young or sick ones.
See the true giants on our biggest dinosaur page, or meet the gentle plant-eating dinosaurs.
Some of the biggest meat-eaters from dinosaur times weren't dinosaurs at all:
Mosasaurus
A giant sea lizard up to about 50 feet long that ruled the oceans at the same time as T. rex.
Giant sea reptiles →Quetzalcoatlus
A flying reptile as tall as a giraffe when standing, with wings as wide as a small plane. It probably stalked small animals on the ground.
Are pterodactyls dinosaurs? →👪 For parents and teachers
“Spinosaurus vs T. rex” is a fun way to show that “biggest” can mean different things: longest, heaviest or strongest. Ask kids to pick a winner for each, then measure 40 and 46 feet in a hallway or playground to see how long these hunters really were.
Spinosaurus was the longest meat-eating dinosaur, at about 46 feet (14 m). Tyrannosaurus rex was a little shorter, about 40 feet, but probably heavier, at 8 to 9 tonnes. Giganotosaurus and Carcharodontosaurus were about as big as T. rex. Different studies give different sizes, so these giants are almost tied.
Spinosaurus was longer, thanks to its long snout and tail, but T. rex was probably heavier and much bulkier. T. rex also had a far stronger bite. So Spinosaurus wins for length, and T. rex wins for weight and power.
They were about the same size. Giganotosaurus may have been slightly longer, about 40 to 43 feet, but the biggest T. rex skeletons were probably a bit heavier. Scientists have found many more T. rex skeletons, so we know its size much better.
No. Spinosaurus lived in North Africa about 95 million years ago, and T. rex lived in North America about 66 million years ago. They were separated by about 30 million years and an ocean!
Utahraptor was the biggest raptor, about 18 to 23 feet long and as heavy as a polar bear. The real Velociraptor was only about the size of a turkey, much smaller than the raptors in movies.
No. The biggest plant-eaters, long-necked titanosaurs like Argentinosaurus, were about 8 to 10 times heavier than the biggest meat-eaters. A T. rex would have looked small standing next to one!
On land, the biggest meat-eaters today are polar bears and brown bears, which can weigh up to about 1,500 pounds. A big T. rex weighed more than a dozen polar bears. In the ocean, the sperm whale is the biggest hunter with teeth.
Image credits: all pictures on this page, including the hero picture, the to-scale chart, the dinosaur size drawings and the Spinosaurus and T. rex illustrations, are original Puffsaurus artwork.
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