MAZON CREEK (DESMONESIAN, PENNSYLVANIAN) FERN AND PTERIDOSPERM FOSSILS: STEMS, WOOD, BARK, BRANCHES, RACHIS

A collection of 436 Mazon Creek fossils was reviewed for stems, bark, wood, branch and rachis like fossils. It yielded 44 such fossils.The fossils were partially collected years ago and partially recently.The Mazon Creek area (Grundy, Will, Kankakee counties, Illinois) is one of the most famous fossil localities in the world and it is classified under Fossil-Lagerstaetten. Mazon Creek fossils are from Francis Creek Shale, Carbondale Formation. Described here, the collection was divided for study purposes in following categories:1)Stem. 2)Wood. 3)Bark. 4)Branch. 5)Rachis. Only ferns and pteridosperms are part of present study.In paleobotanical studies these parts of plants have often received less attention than the leaves and reproductive organs. Particular attention was paid to a few specimens with a physical connection between the stems and/or branches in one group and the leaves and/or reproductive organs in another. Two specimens of the first mentioned connection in this study are stem - large neuropterid leaf and branch - pecopterid foliage combination. Such combinations are particularly useful in paleobotanical studies and are rare among Mazon Creek plant fossils, at least in present collection.