CHAPTER VIII.
THE BEAKED DINOSAURS (Continued.) C.THE ARMORED DINOSAURS--STEGOSAURUS, ANKYLOSAURUS.
_Sub-Order Stegosauria._ This group of dinosaurs is most remarkable for the massive bony armor plates, crests or spines covering the body and tail.

They were more or less completely quadrupedal instead of bipedal, with straight post-like limbs and short rounded hoofed feet adapted to support the weight of the massive body and heavy armature.

Although so different superficially from the bird-footed biped Iguanodonts they are evidently related to them, for the teeth are similar, and the horny beak, the construction of the pelvis, the three-toed hind foot and four-toed front foot all betray relationship.

From what we know of them it seems probable that they evolved from Iguanodont ancestors, developing the bony armor as a protection against the attacks of carnivorous dinosaurs, and modifying the proportions of limbs and feet to enable them to support its weight.

They were evidently herbivorous and some of them of gigantic size.