Dilophosaurus wetherilli

Overview

Dilophosaurus, meaning "two-crested lizard," was one of the largest predators of the Early Jurassic period, living approximately 193 million years ago. Famous for its distinctive paired head crests, this dinosaur is often misrepresented in movies—the real animal was very different from its Hollywood portrayal!

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Taxonomy & Classification

• Clade: Theropoda
• Family: Dilophosauridae
• Diet: Carnivorous
• Locomotion: Bipedal

Dilophosaurus was one of the earliest large predatory dinosaurs.

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Physical Characteristics

Size & Build

• Length: About 7 meters (23 feet)
• Height: About 1.5 meters at the hip
• Weight: Approximately 400 kg (880 lbs)
• Build: Slender and lightweight

The Famous Double Crests

The most recognizable feature:

• Two parallel bony crests on top of its head
• Each crest ran from the snout to above the eye
• Made of thin bone—too fragile for combat
• Probably used for display and recognition
• May have been brightly colored!

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Movie Myths vs. Reality

Jurassic Park Got It WRONG!

Movie Version	Real Dilophosaurus
Small (dog-sized)	Actually 7 meters long!
Expandable frill	No frill at all
Spits venom	No evidence of venom
Hunts by spitting	Hunted like other theropods

The Real Dilophosaurus:

• Was much larger than shown in movies
• Had NO neck frill
• Did NOT spit venom (this was made up!)
• Was a serious predator, not a small scavenger

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Hunting & Diet

What Did It Eat?

Dilophosaurus hunted:

• Small to medium dinosaurs
• Early mammals
• Fish (fossils found near water)
• Reptiles and amphibians

Hunting Style

• Probably a fast runner
• Used speed to catch prey
• Slashing bites to wound
• May have hunted in groups

Jaw Design

• Jaws had a notch between front and back teeth
• Similar to crocodiles—good for gripping
• Could hold onto struggling prey

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Fossil Discoveries

Where Found

• First discovered in Arizona, USA in 1942
• Named in 1954
• Found in the Kayenta Formation
• Multiple specimens known

Trackways

Dilophosaurus footprints have also been found:

• Show it could run quickly
• Traveled in groups (multiple tracks together)
• Help us understand how it moved

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The Crests Mystery

What Were They For?

Scientists have ideas but aren't certain:

• Attracting mates (like peacock feathers)
• Species recognition (identifying each other)
• Social signaling (showing age or status)
• Temperature regulation (unlikely given their small size)

The crests were too fragile for fighting—they'd break easily!

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Early Jurassic World

Dilophosaurus's Environment

• Lived in semi-arid floodplains
• Near seasonal rivers and lakes
• Climate was warm and dry with rainy seasons
• One of the top predators of its ecosystem

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Cool Facts

• The movie version is only about 1/3 the actual size!
• No dinosaur is known to spit venom—that was movie fiction
• Its crests were as thin as playing cards
• Dilophosaurus is the state dinosaur of Connecticut (where its footprints were found)
• It lived 50 million years before the famous T. rex
• Recent studies show it was more powerful than previously thought
• Baby Dilophosaurus probably didn't have full crests yet

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The real Dilophosaurus was nothing like its movie counterpart—it was actually bigger, didn't spit venom, and had no neck frill. Sometimes reality is just as cool as fiction!