Brontosaurus excelsus

Overview

Brontosaurus, meaning "thunder lizard," is one of the most famous dinosaurs in history—even though scientists once said it didn't exist! Living during the Late Jurassic period, about 154-153 million years ago, this magnificent giant has one of the most dramatic stories in paleontology!

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Taxonomy & Classification

• Clade: Sauropoda
• Family: Diplodocidae
• Diet: Herbivorous
• Locomotion: Quadrupedal

Brontosaurus is closely related to Apatosaurus—so close that scientists argued about whether they were the same animal for over 100 years!

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Physical Characteristics

Enormous Size

• Length: 21-22 meters (69-72 feet)
• Weight: Up to 30,000 kg (33 tons)
• Height: About 6.5 meters (21 feet) to the top of the back
• Neck length: About 6 meters (20 feet)

Body Features

• Long, muscular neck (more slender than Apatosaurus)
• Whip-like tail with a thin, tapering end
• Barrel-shaped body like a massive tank
• Pillar-like legs to support immense weight
• Small head with peg-like teeth

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The Great Name Debate

A Dinosaur Lost and Found!

Year	What Happened
1879	O.C. Marsh names Brontosaurus
1903	Scientists declare it's just Apatosaurus!
1903-2015	"Brontosaurus" technically invalid
2015	New study says it's different!
Today	Brontosaurus is officially valid again!

For over 100 years, scientists said you shouldn't call it Brontosaurus—but the public never stopped using the name! Turns out, everyone was right to keep calling it that!

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What Makes It Different?

Brontosaurus vs. Apatosaurus

Feature	Brontosaurus	Apatosaurus
Neck	More slender, higher	Thicker, lower
Body	Slightly lighter	More robust
Shoulder	Different shape	Different proportions
Name meaning	Thunder lizard	Deceptive lizard

The differences are subtle but real enough to make them separate dinosaurs!

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Feeding & Diet

Vegetarian Giant

Brontosaurus spent most of its time eating:

• Ferns covering the forest floor
• Cycads and ginkgo trees
• Conifer needles and branches
• Horsetails and other low plants

Eating Habits

• Couldn't chew—swallowed plants whole
• Needed to eat hundreds of kilograms daily
• Gut bacteria helped digest tough plants
• May have used stones in stomach (gastroliths) to grind food
• Fed for most of waking hours

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The Thunder Lizard Name

Why "Thunder Lizard"?

O.C. Marsh imagined:

• The ground shaking as it walked
• Footsteps sounding like thunder
• A creature so massive it made the earth tremble
• One of the most evocative dinosaur names ever given!

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Defense & Survival

Protecting Itself

Despite being peaceful, Brontosaurus had defenses:

• Massive size scared most predators
• Whip-crack tail could break bones
• Herd living provided safety
• Stomping could crush attackers
• Young protected by adults in group

Main Threat

• Allosaurus was its primary predator
• Probably attacked young or sick individuals
• Adult Brontosaurus was likely too big to tackle

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Herd Behavior

Social Giants

Evidence suggests:

• Lived in herds for protection
• Migrated following food sources
• Young stayed close to adults
• Trackways show multiple individuals traveling together
• May have had complex social structures

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Growth & Development

From Egg to Giant

• Eggs were about the size of grapefruits
• Babies were tiny compared to adults
• Grew at incredible rates—several tons per year!
• May have reached full size in 10-15 years
• Could potentially live for 100+ years

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Discovery & History

Famous Fossil Finds

• Named by O.C. Marsh in 1879
• Found in the Morrison Formation, Western USA
• Discovered during the Bone Wars between rival scientists
• Specimens found in Wyoming, Colorado, Utah
• One of the most mounted dinosaurs in museums

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The Morrison Formation

Jurassic World

Brontosaurus lived alongside:

• Allosaurus (fearsome predator)
• Stegosaurus (plate-backed herbivore)
• Diplodocus (long-necked cousin)
• Apatosaurus (close relative)
• A diverse ecosystem of Jurassic giants

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Cool Facts

• The name "Brontosaurus" was used in movies and books for decades after scientists said it was wrong!
• A 2015 study using computer analysis proved it was a valid dinosaur
• Its tail could crack like a bullwhip at supersonic speeds
• The brain was only about the size of a large orange
• Required a heart as big as a small car to pump blood to its head
• Despite weighing 30 tons, its neck was mostly air sacs!
• Footprints were big enough to sit in
• One of the most recognized dinosaurs in popular culture

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Brontosaurus is the dinosaur that wouldn't stay dead—even when scientists said it didn't exist, the "thunder lizard" stomped right back into the history books!