Allosaurus vs Pachycephalosaurus

A detailed side-by-side comparison of Allosaurus and Pachycephalosaurus, covering size, diet, classification, geologic period, and discovery history.

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Side-by-Side Comparison

คุณสมบัติ Allosaurus Pachycephalosaurus
ชื่อวิทยาศาสตร์ Allosaurus fragilis Pachycephalosaurus wyomingensis
การจำแนกประเภท Theropoda Pachycephalosauria
ยุคสมัย Jurassic Late Cretaceous Late
อาหาร Carnivore Herbivore
ความยาว 9.7 m 4.5 m
Height 3.5 m 1.8 m
น้ำหนัก 2.3 t 450 kg
ปีที่ค้นพบ 1877 1943
สถานที่ค้นพบ Garden Park, Colorado, USA Montana, USA
ตั้งชื่อโดย Othniel Charles Marsh Barnum Brown & Erich Schlaikjer
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Size Comparison

Allosaurus 9.7 m

roughly the length of a large SUV

Pachycephalosaurus 4.5 m

roughly the length of a large SUV

Weight Comparison

Allosaurus 2.3 t

comparable to 2.3 small cars

Pachycephalosaurus 450 kg

about 6 adult humans

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Timeline Comparison

Allosaurus
161.5 Mya Jurassic Late (Mesozoic) 145.0 Mya
Pachycephalosaurus
100.5 Mya Cretaceous Late (Mesozoic) 66.0 Mya
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Diet Comparison

Allosaurus

Carnivore

Allosaurus was a meat-eating predator, hunting other animals for food.

Pachycephalosaurus

Herbivore

Pachycephalosaurus was a plant-eater, feeding on vegetation like ferns, conifers, and cycads.

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Classification Comparison

Allosaurus

Clade: Saurischia

Group: Theropoda

(Beast feet)

Pachycephalosaurus

Clade: Ornithischia

Group: Pachycephalosauria

(Thick-headed lizards)

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Did You Know?

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Allosaurus was about 2.2x longer than Pachycephalosaurus.

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Allosaurus weighed roughly 5x more than Pachycephalosaurus.

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Allosaurus was a carnivore while Pachycephalosaurus was a herbivore.

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Allosaurus lived during the Jurassic Late while Pachycephalosaurus lived during the Cretaceous Late, separated by roughly 44 million years.

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Allosaurus was discovered 66 years earlier, in 1877.

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Allosaurus belonged to Theropoda while Pachycephalosaurus belonged to Pachycephalosauria.

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