Tully Monster (Tullimonstrum gregarium) with Eye Bar ed32456c059749639848a8dc79b96d64 In some instances

In some instances

In this slow process

Corundum by itself is colorless

octahedral or dodecahedral crystals

the mineral Septarian formed in an ancient sea floor some 50-70 million years ago as sediment collected around sea life as they decomposed

Tully Monster (Tullimonstrum gregarium) with Eye Bar ed32456c059749639848a8dc79b96d64 In some instancesTullimonstrum 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