Stegosaurus: The Hedgehog
140 million BC
-1000140 -1000140
107.00W44.00N
NAT

MIDWEST NORTH AMERICA
	Though not always able to outrun its carnivorous foes, the 21-foot-long stegosaurus always had a final line of defense -- its bony-plated back and spiny tail.
	If cornered or unable to outrun a larger enemy, the stegosaurus' back plates afforded some protection while the four to eight spikes on the end of its tail (which grew as long as four feet) made it dangerous for a foe to approach too carelessly.
	Scientists still don't agree about the placement of the vertical plates along the stegosaurus' back. The plates are not attached to bone, but were imbedded in the dinosaur's back, which makes it difficult to tell if they were in a single row, double row or a combination of the two.
	Many scientists believe the verticle plates also served as warming or cooling fins, picking up heat from the sun when the weather was cool to warm the stegosaurus, or giving off heat when it was too hot.
	Stegosaurus bones have been found in Colorado and Wyoming, and are believed to have lived primarily in western North America.