Thyreophora

Thyreophora; Temporal range: Early Jurassic-Late Cretaceous,
	Four armored dinosaurs. Counterclockwise from top left: Edmontonia (a nodosaur), Scelidosaurus (an early thyreophoran), Stegosaurus (a stegosaur), and Saichania (an ankylosaur)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Genasauria
Clade:	†Thyreophora; Nopcsa, 1915
Subgroups
	†Bienosaurus ; †Emausaurus; †Laquintasaura?; †Lesothosaurus?; †Scutellosaurus; †Tatisaurus; †Thyreophoroidea Nopcsa, 1928 †Jakapil?; †Scelidosaurus; †Yuxisaurus?; †Eurypoda Sereno, 1986 †Ankylosauria; †Stegosauria; ; ;
	Thyreophorans distribution map

Thyreophora ("shield bearers"), often known simply as armored dinosaurs is a group of armored ornithischian dinosaurs that lived from the Early Jurassic until the end of the Cretaceous.

Thyreophorans are characterized by the presence of body armor lined up in longitudinal rows along the body. Primitive forms had simple, low, keeled scutes or osteoderms, whereas more derived forms developed more elaborate structures including spikes and plates. Most thyreophorans were herbivorous and had relatively small brains for their body size.

Thyreophora includes two major subgroups, Ankylosauria and Stegosauria. In both clades, the forelimbs were much shorter than the hindlimbs, particularly in stegosaurs. Thyreophora has been defined as the group consisting of all species more closely related to Ankylosaurus and Stegosaurus than to Iguanodon and Triceratops. It is the sister group of Cerapoda within Genasauria.