INVESTIGATION OF CORDAITEAN PHYLOGENESIS WITH CORDAITEAN SEEDS
MetadataShow full item record
Cordaiteans are a group of plants present during the Carboniferous and Permian; the group is held together largely by the characteristic leaves. Cordaiteans are gymnosperms (seed-bearing plants). The group includes many genera that are known only from seeds. This creates an inherent problem with describing phylogenetic associations/evolutionary relationships among the different species, since many traits (e.g. traits of the stem, leaves, and cones) are missing. In order to try and make a phylogenetic tree linking all cordaiteans, including those known only from seeds, we developed a traits matrix using only seed and pollen traits. The starting taxa selected for the study come primarily from Hilton et al. (2003, Bot. J. Lin. Soc 141: 151-175) ?Reinvestigation of Cardiocarpus minor (Wang) Li nomen nudum from the Lower Permian of China and its implications for seed plant taxonomy, systematics and phylogeny.? Taxa known only from immature ovules (e.g. ovules known only from fertile cones) are dropped from the study. Various ways of coding traits were investigated to see the effect of trait coding on phylogenetic trees. Cladistic analysis reveals a strong relationship among the mitrospermeans, while cardiocarpaleans were less strongly associated. Results suggest that developing a consensus on how to code seed traits would improve phylogenetic trees of ancient land plants.
Correa, Julian 1990- (2012). INVESTIGATION OF CORDAITEAN PHYLOGENESIS WITH CORDAITEAN SEEDS. Honors and Undergraduate Research. Available electronically from