MESOFOSSILS FROM BLACK WOLF, KANSAS

A fire event not only destroys existing vegetation, it also yields mesofossils and produces a mark for itself in ancient sediments. In recent years, study of mesofossils charcoalified during fire events have triggered an explosion of knowledge about the existence of gymnosperms and angiosperms during the Cretaceous. We collected sediments rich in charcoalified wood and diverse plant fragments from the Dakota Formation near Black Wolf, Kansas. Sieving these samples yielded a variety of mesofossils. These fossils include different parts of plants in various groups including ferns, gymnosperms and angiosperms. Up to now, we have identified about 50 species (127 pieces) of seeds, 1 species (33 pieces) of fruit, 12 species (22 pieces) of seed/flower bases, 6 species (87 pieces) of cone scales, 3 species (9 pieces) of fern shoots, 8 species (17 pieces) of gymnosperm and/or angiosperm shoots, 4 species (11 pieces) of gymnosperm leaves, 7 species (40 pieces) of gymnosperm cones, 2 species (3 pieces) of angiosperm inflorescences. These fossils form unique assemblages from each sedimentary bed sampled at Black Wolf. Preserved with these charcoalified mesofossils are also aquatic fern megaspores which were not charcoalified, this fact implies that some plant fragments derived from an aquatic environment were also incorporated into these sediments. The presence, domination and preservation of different taxa in the assemblages tell us that these plants survived fire events, recolonized the same areas which were burned again. The study of mesofossils bridges the gap between studies of megafossils and palynology, and provides us a new aspect on the Dakota flora and its ecology, locally and regionally.