Colorado: Stegosaurus stenops (state fossil)
Colorado: Stegosaurus stenops (state fossil)
Popular with dinosaur lovers of all ages, the familiar plated herbivore Stegosaurus is an appropriate state fossil for Colorado, both because its bones are plentiful in Morrison Formation sediments, and because some of the most important discoveries have been made in the state.
At the time when Stegosaurus roamed Colorado, the area was a vast lowland plain dotted with streams, rivers, and lakes. The Ancestral Rockies were worn down to low hills, and the present Rocky Mountains had yet to form. The time was the Jurassic Period, around 145 million years ago, and dinosaurs were plentiful and diverse throughout the world.
Stegosaurus was a large, quadrupedal dinosaur which probably fed on low-growing plants like ferns and cycads. The prominent plates running down its spine may have been used for defense, or as a temperature-regulating mechanism.
The first Stegosaurus was found just west of Denver in 1877. The collector shipped bones to two prominent professors, E. D. Cope and O. C. Marsh, igniting a rivalry that would come to be called the "bone wars." Important discoveries continue today, notably the 1992 find near Cañon City of an almost-complete specimen.
A fourth-grade class campaigned across the state for two years to designate Stegosaurus a Colorado symbol. Their efforts culminated in an executive order issued by the governor on April 28, 1982 making this popular dinosaur the official state fossil.
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