What Was the Biggest Dinosaur Ever?

The biggest dinosaur ever discovered is believed to be Argentinosaurus, a massive long-necked plant-eater that lived around 90 million years ago.

Some dinosaurs grew to incredible sizes, stretching over 30 metres long and weighing as much as multiple elephants combined.

🦕 Argentinosaurus – The Largest Dinosaur

• Length: about 30–35 metres
• Weight: up to 100 tonnes
• Diet: plant-eater (herbivore)
• Type: sauropod (long-neck dinosaur)

Argentinosaurus is known from fossil remains found in South America. Although scientists have not found a complete skeleton, estimates based on bones suggest it was one of the largest land animals ever.

Other Huge Dinosaurs

Patagotitan

• Length: around 30 metres
• Weight: 60–70 tonnes
• One of the most complete giant dinosaur skeletons found

Brachiosaurus

• Length: about 25 metres
• Known for its long front legs and tall posture

Diplodocus

• Length: up to 30 metres
• Long, whip-like tail

Supersaurus

• Possibly over 30 metres long
• One of the longest dinosaurs ever discovered

How Big Were These Dinosaurs Compared to Today?

• Longer than a bus
• Taller than a multi-storey building
• Heavier than multiple elephants combined

No land animals alive today come close to the size of the largest dinosaurs.

How Do Scientists Know Their Size?

Scientists estimate dinosaur size using fossil bones and comparisons with modern animals.

• Measuring fossil bones
• Comparing skeleton structures
• Using computer models
• Estimating muscle and body mass

Because many fossils are incomplete, size estimates can change as new discoveries are made.

Why Did Dinosaurs Grow So Large?

• Abundant plant food sources
• Efficient breathing systems
• Less competition from mammals
• Evolution over millions of years

Large size may also have helped protect them from predators.

Were the Biggest Dinosaurs Carnivores?

No — the largest dinosaurs were plant-eaters.

The biggest meat-eating dinosaurs, like Tyrannosaurus rex and Spinosaurus, were large but much smaller than the biggest sauropods.

Summary

• The biggest dinosaur ever was likely Argentinosaurus
• It may have reached over 30 metres long
• It weighed up to 100 tonnes
• Other giant dinosaurs include Patagotitan and Brachiosaurus
• All of the largest dinosaurs were plant-eaters

⚠️ Disclaimer

This page provides general educational information based on current paleontology research. Estimates of dinosaur size may change as new fossils are discovered.

This page is not affiliated with or endorsed by any scientific organisation or museum. For detailed scientific study, consult official research sources and academic publications.