Hesperosaurus

Animalia

Hesperosaurus Temporal range: Late Jurassic, 150 Ma PreЄ Є O S D C P T J K Pg N ↓
Mounted skeleton
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Dinosauria
Order:	†Ornithischia
Suborder:	†Stegosauria
Family:	†Stegosauridae
Genus:	†Hesperosaurus Carpenter, Miles & Cloward, 2001
Species:	†H. mjosi
Binomial name
Hesperosaurus mjosi Carpenter, Miles & Cloward, 2001

Hesperosaurus (meaning "western lizard", from Classical Greek, ἕσπερο-/hespero- "western" and σαυρος/saurus "lizard") was a herbivorous dinosaur from the Kimmeridgian to Tithonian epochs of the Jurassic period (approximately 150 million years ago), whose fossils are found in the state of Wyoming in the United States of America. It is from an older part of the Morrison Formation, and so a little older than other Morrison Stegosaurs.

Hesperosaurus was a type of stegosaurid, having alternating plates on its back and four spikes on its tail. The plates on its back were not as tall, but were longer, than in its cousin Stegosaurus. It had a shorter, broader skull than Stegosaurus and appears most closely related to Dacentrurus.

Discovery and species

It was described in 2001 by Kenneth Carpenter and colleagues, who took the name for its location in the western United States. A nearly complete skull and much of the skeleton was found. The only species known is Hesperosaurus mjosi. It is present in stratigraphic zone 1 of the Morrison Formation.

Susannah Maidment and colleagues proposed in 2008 that Hesperosaurus should be considered a synonym of Stegosaurus, with H. mjosi becoming Stegosaurus mjosi.

References

• Carpenter K, Miles CA, Cloward K (2001). "New Primitive Stegosaur from the Morrison Formation, Wyoming". In Carpenter, Kenneth(ed). The Armored Dinosaurs. Indiana University Press. pp. 55–75. ISBN 0-253-33964-2. 

External links

• Page on stegosaurs, including Hesperosaurus