Mazon Creek Fern P-MC-16-017 Eocene Brontosaurus has long been considered

Brontosaurus has long been considered a junior synonym of Apatosaurus

The elytra are spread at 90 degrees to the thorax but have extraordinary preserved color-banding

It has a gently toothed margin

Heliobatis individuals have up to three modified dermal denticles

Apatosaurus had a single claw on each forelimb and three on each hindlimb

Mazon Creek Fern P-MC-16-017 Eocene Brontosaurus has long been consideredNeuropteris 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