Scutellosaurus (/skuːˌtɛloʊˈsɔːrəs/ skoo-TEL-oh-SOR-əs) is a genus of basal thyreophoran dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now Arizona, USA.

[1] Scutellosaurus was a small, lightly-built, ground-dwelling herbivore, that could grow up to an estimated 1.3 metres (4.3 ft) long.

The holotype specimen of Scutellosaurus lawleri (MNA.V.175) was recovered at the West Moenkopi Plateau locality in the Silty Facies Member of the Kayenta Formation, in Coconino County, Arizona on the land of the Navajo Nation.

The specimen was discovered and collected by David Lawler in red claystone sediments that were deposited during the Sinemurian stage of the Jurassic period, approximately 196 million years ago.

The holotype specimen was described by Edwin Colbert (1981) based on the following:[3] partially preserved premaxillae with teeth, a right maxilla with seven teeth, a left maxilla with five teeth, dentaries that are missing their posterior portions, a left dentary with 18 teeth, a right dentary with 10 teeth, other skull fragments, 21 presacral vertebral centra, several complete and partial neural arches and spines, five sacral vertebrae, 58 caudal vertebrae with neural arches and several chevrons, several incomplete ribs, both scapulae, both coracoids, partially preserved ilia, fragments of the pubic bones and of the ischia, both humeri, the distal end of the right radius, the proximal and distal ends of the left radius and ulna, fragments of the manus, both femora, the right tibia, the proximal end of the right fibula, the right astragalus, the left tibia, the left fibula, various bones of the pedes, including a possible distal tarsal bone, and over 300 osteoderms.