Tullimonstrum gregarium, Tully Monster Mammoth / Mastodon It is generally found with

It is generally found with its mineral cousin malachite which is why you can get both colors in one rock

Malachite is also found as a pseudomorph

with warm body colors of yellow to orange to red

Stegosaurus would have lived alongside dinosaurs such as Apatosaurus

~ 5"  x  5"  x  2" high

Tullimonstrum gregarium, Tully Monster Mammoth / Mastodon It is generally found withTullimonstrum gregarium, popularly known as The Tully Monster, is the Illinois State Fossil & is perhaps one of the most mysterious fossils ever unearthed Age of the Tully Monster During the Pennsylvanian Period (roughly 307 million years ago), the land that is now Illinois lay near Earth's equator. Dense swamps, forested with primitive plants, covered much of western and central Illinois. In shallow seas nearby, the Tully monster swam along with