Dinosaur Mountain - Jurassic Arizona
The second level from the bottom of the mountain represents the plants
and animals of the Jurassic Period Morrison Formation, about 155 million
years ago. Many of the best-known dinosaurs lived in the Jurassic, when
sauropods, the long-necked dinosaurs, dominated the landscape. The Morrison
Formation has been the site of many finds in Utah, Colorado and New Mexico,
but so far few dinosaurs have been found in the Morrison Formation in
At over 20 feet long and weighing up to two tons (4,000 pounds), this was
the largest member of the stegosaur group. The plates on the back may have
had a defensive function, as scientists have long supposed, but the
excellent circulation system in the plates suggests they may have been for
temperature control, acting as radiators and solar collectors.
This small crocodilian was a swift upland predator, apparently dominating
the small predator niche in the early Morrison Formation. At several times
and places, some crocodilians have left their traditional aquatic life and
pursued a more terrestrial strategy.
Echinodon & Termite Nest
The small, plant-eating dinosaur, Echinodon, reached only about 24
inches in length and is one of the smallest dinosaurs known. Fossils of
Echinodon have been found in Colorado, England and Portugal.
Recent discoveries in New Mexico show that termite nests appeared in the
Morrison Formation. Some of these nests were over 100 feet tall. Termites
build their nests by bonding sand grains together with their saliva, feces
and partly digested wood material.