Stegosaurus Dinosaur Coloring Page & Printable PDF

Stegosaurus Dinosaur: History & Fun Facts

When Stegosaurus Dinosaur Roamed the Earth

Stegosaurus is famous for the two rows of bony plates along its back and the spikes on its tail called a thagomizer. Scientists believe the plates may have been used for display, regulation of body temperature or defence. It lived during the Late Jurassic period about 145 million years ago in what is now western North America. The spikes on its tail could swing as a powerful weapon to deter predators like Allosaurus and Ceratosaurus. Stegosaurus was a plant-eater weighing up to 14,000 pounds and had a brain only slightly bigger than a walnut.

Stegosaurus is famous for the row of large plates along its back and the spikes at the end of its tail. The exact job of the plates is still debated, but they may have helped with display or body regulation, while the tail spikes were likely more useful for defense. Those back plates make Stegosaurus one of the easiest dinosaurs to identify at a glance.

Plate Shape, Count, and Arrangement

Most Stegosaurus skeletons show 17 plates running in two offset rows down the neck, back, and tail rather than a matched pair-by-pair arrangement. The plates near the hips grew largest, some reaching over two feet tall, while the ones near the neck stayed smaller and more rounded. Fossil surfaces show grooves that likely carried blood vessels, which supports the idea that the plates could flush with color when the animal was excited or threatened.

The Thagomizer and Combat Evidence

The four tail spikes, later nicknamed the thagomizer after a joke in a Far Side comic strip, could measure up to three feet long each. A fossil Allosaurus tailbone found with a puncture wound matching a thagomizer spike gives direct evidence that Stegosaurus actually used its tail in combat rather than just for display. The tail itself was flexible enough to swing sideways with real force, unlike the stiffer tails of many other plant-eating dinosaurs.

A Surprisingly Small Head for Its Size

Despite growing up to 30 feet long, Stegosaurus carried a narrow skull barely longer than a horse's head, with a beak suited for clipping ferns, cycads, and low shrubs rather than tall trees. Its brain, roughly the size of a walnut, sits at the small end of the scale even for dinosaurs, though its sense of smell and hearing were likely sharper than its intelligence suggests. That mismatch between a small head and a heavily armored back is part of what makes the animal instantly recognizable in silhouette.

Coloring the Plates and Thagomizer

The back plates give this coloring page its most flexible area, since real evidence supports anything from muted grays to bright reds depending on the display theory a child wants to imagine. The four tail spikes work well in a darker contrasting shade to make them stand out from the body, and the short, sturdy legs can be left simple so the plates and spikes stay the visual focus of the finished page.

Alternating colors between the offset rows of plates can help highlight the zigzag pattern running down the back, which is exactly how paleontologists believe the plates were staggered in life. Leaving the small bumpy scales along the sides a plain, muted tone keeps attention on the plates and thagomizer as the two standout features of the animal.