Dinosaurs A to Z
Stegosauridae

Hesperosaurus mjosi

"western"

Generic stegosaur body-plan outline
You 1.8 m (5.9 ft) tall
Hesperosaurus 6.5 m (21.3 ft) long
as long as 4 people standing fingertip to fingertip
generic stegosaur body plan, scaled to length — not a silhouette of Hesperosaurus
Length
6.5 m (21.3 ft)
Period
Late Jurassic (156 Mya)
Place
United States · Montana, USA · Wyoming, USA
Food
Herbivore
Clade
Stegosauridae Dinosauria Ornithischia Thyreophora Stegosauria Stegosaurus and close relatives.

Hesperosaurus (from Ancient Greek ἕσπερος (hésperos), meaning “western”, and σαῦρος (saûros), meaning “lizard”) is a herbivorous stegosaurian dinosaur from the Kimmeridgian age of the Jurassic period, approximately 156 million years ago.

Fossils of Hesperosaurus have been found in the state of Wyoming and Montana in the United States of America since 1985. The type species Hesperosaurus mjosi was named in 2001. It is from an older part of the Morrison Formation, and so a little older than other Morrison stegosaurs. Several relatively complete skeletons of Hesperosaurus are known. One specimen preserves the first known impression of the horn sheath of a stegosaurian back plate.

What we know

  • Named by Carpenter, Miles & Cloward, 2001.
  • Body length estimated at about 6.5 m.
  • Fossils found in United States and Montana, USA.

What we guess

The reconstruction notes for Hesperosaurus — soft tissue, color, behavior — haven't been written up yet. Only the recorded basics above are filled in so far.