The Late Pennsylvanian flora at Hamilton, KS has yielded approximately three thousand conifer specimens including leafy shoots, pollen cones, ovulate cones, ovules and seeds, and decorticated stems that show a wide range of variation in structural features and preservational modes. These specimens display characters of external morphology, internal anatomy and cuticular detail, and are interconnected in various combinations of organs that provide a large number of characters for formulating and testing hypotheses of taxonomic diversity. These include the morphological and cuticular characters used in classical fossil conifer studies, as well as new information on anatomical and developmental variation, and reproductive biology. Based on our analyses of vegetative shoots, pollen cones, pollen, ovulate cones and ovules/seeds we have identified intergrading combinations of characters for individual organs. When the characters of organs that are in organic attachment are included, these combined analyses allow us to test our hypotheses of taxonomic diversity using multivariate techniques and cladistic methodologies.

Key words: conifer diversity, Late Pennsylvanian, Paleozoic