Dino card No. 0136 of 2,027

Apatosaurus

Say it: uh-PAT-oh-SORE-us

Name means: “deceptive lizard”1

Ate: PlantsLong-necksLate Jurassic to Early Cretaceous

Apatosaurus was a giant, long-necked plant eater that lived about 150 million years ago. It was one of the biggest land animals ever, with a huge body and a very long tail.2 1

Lived

158 to 143 million years ago6

Late Jurassic to Early Cretaceous

Fossils found in

USA, in the Morrison Formation spanning states like Wyoming, Colorado, and Montana1 6

Food

Plants1 6

Length

21 to 23 m1 2

estimates vary

Weight

up to 41 tonnes2

Height

3 to 4.6 m3

at the hips

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

How tall was it?

at the hips

How heavy was it?

as heavy as 7 elephants

as long as 5 cars parked in a rowas long as 130 bananas end to endas heavy as 8200 watermelonsas tall as 2.5 doors stacked up

How big was Apatosaurus compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

cool stuff

Fun facts

Apatosaurus had a long, whiplike tail that might have been used like a whip.1

Young Apatosaurus grew very fast, reaching full adult size in about 10 years.1

Its huge size helped protect it from smaller predators, and living in herds gave extra safety.1

Apatosaurus lived alongside other famous dinosaurs like Stegosaurus, Diplodocus, and Allosaurus.1

The environment where Apatosaurus lived was semi-arid, with forests, rivers, and floodplains, and had distinct wet and dry seasons.1

Apatosaurus weighed as much as five adult elephants.2

AI-made picture of Apatosaurus — An AI-made picture of how Apatosaurus might have looked, made by a computer from what scientists know. It is a guess: the real animal may have looked different, and nobody knows its true colours.

you asked

Most asked questions about Apatosaurus

?How big was Apatosaurus?

About 21 to 23 metres (69 to 75 feet) long and weighed 16 to 22 tonnes (18 to 24 short tons). Some specimens may have been even larger, up to 30 metres (98 feet) long and 33 tonnes (36 short tons).1 2 4

?What did Apatosaurus eat?

It ate plants like ferns, conifers, and other leaves. It swallowed them whole and used stones in its stomach to help digest the tough plant material.1 5

?When did Apatosaurus live?

It lived about 152 to 145 million years ago, during the Late Jurassic Period.1 4

?Where was Apatosaurus found?

Fossils have been found in the United States, in states like Colorado, Wyoming, Utah, Oklahoma, and New Mexico.1 4

?Is Apatosaurus the same as Brontosaurus?

For many years scientists thought they were the same, but a 2015 study says they are separate, closely related dinosaurs. Not all experts agree, though.1 2 4

?How fast could Apatosaurus grow?

Young Apatosaurus grew very quickly and reached full adult size in about 10 years.1

?Could Apatosaurus use its tail as a weapon?

Yes, it had a long, whiplike tail that it might have used like a whip to defend itself or make loud noises.1 4

?Was Apatosaurus bigger than T. rex?

Yes, Apatosaurus was much bigger. It was about 21 to 23 metres long and weighed up to 22 tonnes, while T. rex was about 12 metres long and weighed around 8 tonnes.1 2

?Did Apatosaurus live with Allosaurus?

Yes, they lived alongside each other in the Late Jurassic. Allosaurus was a predator that may have attacked Apatosaurus, but Apatosaurus's huge size helped protect it.1 5

?How did Apatosaurus get its name?

Its name means 'deceptive lizard' in Greek. The scientist who named it, Othniel Charles Marsh, thought some of its bones were confusing and looked like those of a marine reptile.1 5

Ask Rex about Apatosaurus

Rex only answers questions about this page. 10 questions a month.

Rex is an AI and can make mistakes. He runs on servers in the EU and questions are never saved. Never type your name or other personal things.

Myth buster

Myth: Brontosaurus is the same dinosaur as Apatosaurus.

Truth: For over 100 years, scientists thought Brontosaurus and Apatosaurus were the same. But a 2015 study suggests they are separate, closely related dinosaurs.1 2

For dino experts

Scientific name: Apatosaurus
Named by: Marsh 18776
Group: Long-necks
Family / clade: Diplodocidae6
Classification: Sauropodomorpha > Sauropoda > Diplodocoidea6
Age of the rocks: 158 to 143 million years ()6
Rock formations: Morrison6
Countries: USA6
Fossil records: 67 in the Paleobiology Database6
Discovery: Apatosaurus was named by Othniel Charles Marsh in 1877. He chose the name because some of the fossil bones were confusing and seemed to resemble those of a sea reptile.1 6
Still debated: Scientists still debate whether Apatosaurus and Brontosaurus are separate genera or the same.2 1

Where the facts come from

Apatosaurus | Natural History Museum (nhm.ac.uk)
Apatosaurus | Size, Length, & Facts | Britannica (britannica.com)
Apatosaurus/Brontosaurus Fact Sheet (enchantedlearning.com)
Apatosaurus (Wikipedia) (Wikipedia)
Apatosaurus Info - Enchanted Learning (enchantedlearning.com)
Apatosaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at [email protected] and we will fix it.

Rex is hungry! Dino Wiki is a dad's project for his dino-loving son, free with no ads. Grown-ups can feed Rex a snack to help keep it online.Feed Rex