Euphyllophytina, the euphyllophytes, is a taxon – sometimes unranked, sometimes placed at the informal rank of subdivision – within the tracheophytes. It is sister to subdivision Lycopodiophyta. Euphyllophytina contains the two groups Spermatophytes (seed plants) and Monilophytes (ferns), as well as a number of extinct fossil taxa. The division of the extant tracheophytes into three monophyletic lineages is supported in multiple molecular studies. Other researchers state that taking fossils into account leads to different conclusions, for example that the ferns are not monophyletic.
The following phylogram shows one view of the relationships between the taxa described above.
^Smith, A. R., K. M. Pryer, et al. (2006). "A classification for extant ferns." Taxon55(3): 705-731
^Pryer, K. M., H. Schneider, et al. (2001). "Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants." Nature409(6820): 618-22
^ abPryer, K. M., E. Schuettpelz, et al. (2004). "Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences 1". Botanical Soc America91: 1582-1598
^Rothwell, G.W. & Nixon, K.C. (2006), "How Does the Inclusion of Fossil Data Change Our Conclusions about the Phylogenetic History of Euphyllophytes?", International Journal of Plant Sciences167 (3): 737–749, doi:10.1086/503298