Mazon Creek Fern P-MC-16-012 Jurassic This is a very interesting

This is a very interesting assemblage of insects arrange in a linear strand

But those between these two extremes benefited from ideal conditions

ostracod grainstone

The phragmocone is variously tuberculate

This example is collected from the 18-inch layer

Mazon Creek Fern P-MC-16-012 Jurassic This is a very interestingPecopteris sp. Carbondale Formation Middle Pennsylvanian Grundy County, Illinois Complete siderite nodule with a very well preserved fern frond. The Mazon Creek area fossils are found mostly in siderite concretions. The concretions are found in the Francis Creek Shale Member within the Carbondale Formation of the Kewanee Group. The best nodules are a by product of coal strip mining operations. The age of the fossil plants is Desmoinesian, Middle