Stegosaurs facts for kids

The Stegosaurs were a fascinating group of dinosaurs known for their unique bony plates and spikes. These plant-eating dinosaurs had small heads and peg-like teeth. They lived from the Middle Jurassic to the Lower Cretaceous periods, about 176 to 100 million years ago.

Quick facts for kids Stegosauria Temporal range: Middle Jurassic – Lower Cretaceous, 176–100 mya
Fossil skeleton of a Stegosaurus, National Museum of Natural History
Scientific classification
Kingdom:	Animalia
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Ornithischia
Suborder:	Thyreophora
Infraorder:	Stegosauria

A fossil display showing a stegosaurian (Tuojiangosaurus) and a mid-sized theropod (Monolophosaurus) at the Field Museum in Chicago.

What Were Stegosaurs Like?

Stegosaurs were easily recognized by the two rows of large, bony plates along their backs. They also had sharp spikes on their tails, which they likely used for defense against predators. Their small heads and simple, peg-like teeth suggest they ate soft plants.

Different Kinds of Stegosaurs

The group of dinosaurs called Stegosauria was first named by Othniel Charles Marsh in 1877. Today, scientists consider Stegosauria a smaller group within the Thyreophora, which are all the armoured dinosaurs. Stegosauria includes two main families: the Huayangosauridae and the Stegosauridae.

Early Stegosaurs: Huayangosauridae

The Huayangosauridae were an early family of stegosaurs. They lived during the Middle Jurassic period. These dinosaurs were generally smaller than the later stegosaurs and had shorter, taller skulls. The best-known dinosaur in this family is Huayangosaurus, found in China. There's also a dinosaur called Regnosaurus from England that might belong to this group, but we don't have many fossils of it.

Later Stegosaurs: Stegosauridae

Most stegosaurs belong to the Stegosauridae family. These dinosaurs lived later, during the Upper Jurassic and Lower Cretaceous periods. This family includes the very famous Stegosaurus. Stegosauridae dinosaurs were found all over the Northern Hemisphere and in Africa, showing they were quite widespread.

Stegosaur Family Tree

Here are some of the known stegosaurs and where their fossils have been found:

Suborder Thyreophora (Armored Dinosaurs)

Infraorder Stegosauria

• Family Huayangosauridae
  • Huayangosaurus (Sichuan, China)
  • ?Regnosaurus (Sussex, England)

• Family Stegosauridae
  • Chialingosaurus – (Sichuan, China)
  • Chungkingosaurus – (Chongqing, China)
  • Dacentrurus – (England, France & Spain)
  • Hesperosaurus – (Wyoming, USA)
  • Miragaia – (Portugal)
  • Monkonosaurus – (Tibet, China)
  • Paranthodon – (South Africa)
  • Wuerhosaurus – (Xinjiang, Western China)
  • Kentrosaurus – (Tanzania, Africa)
  • Lexovisaurus – (England & France)
  • Stegosaurus – (Wyoming, USA)
  • Tuojiangosaurus – (Sichuan, China)
  •  ?Craterosaurus – (Bedfordshire, England)
  • Jiangjunosaurus – (Xinjiang, Western China)

• Uncertain placement (incertae sedis - meaning its exact family is not yet clear)
  • Gigantspinosaurus – (Sichuan, China)

Images for kids

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  A Stegosaurus skeleton showing its high neck, throat bones, and strong shoulders and front legs.

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  Stegosaurus bones drawn by Arthur Lakes in 1879.

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  Huayangosaurus is the oldest and most basic stegosaur we have good fossils of, giving us an idea of what the earliest members of this group looked like.

See also

In Spanish: Stegosauria para niños