G.  Mapes and Rothwell, G. W., ?Validation of the names Emporiaceae, Emporia, and Emporia lockardii?, Taxon, vol. 52, pp. 327?328, 2003.

K. Jeet Singh, Rothwell, G. W., Mapes, G., and Chandra, S., ?Reinvestigation of the coniferophyte morphospecies Buriadia heterophylla Seward and Sahni, with reinterpretation of vegetative diversity and putative seed attachments?, Review of Palaeobotany and Palynology, vol. 127, no. 1-2, pp. 25-43, 2003.

G. W.  Rothwell, Mapes, G., Stockey, R. A., Hilton, J., and Bateman, R. M., ?Descent with modification, transformational series, and phylogenetic analyses to infer the evolution of modern conifer families, in Abstracts GSA Annual Meeting Portland?, Geological Society of America Abstracts with Program, vol. 41, no. 7, p. 563, 2009.

G. W.  Rothwell, Mapes, G., and Mapes, R. H., ?Anatomically preserved vojnovskyalean seed plants in Upper Pennsylvanian (Stephanian) marine shales of  North America?, Journal of Paleontology, vol. 70, no. 6, pp. 1067-1079, 1996.

G.  Mapes and Rothwell, G. W., ?Permineralized ovulate cones of Lebachia from Late Palaeozoic limestones of Kansas?, Palaeontology, vol. 27, pp. 69-94, 1984.

G. R.  Hernandez-Castillo, Stockey, R. A., Rothwell, G. W., and Mapes, G., ?Reconstructing Emporia lockardii (Voltziales: Emporiaceae) and initial thoughts on palaeozoic conifer ecology?, International Journal of Plant Sciences, vol. 170, pp. 1056-1074, 2009.

G. R.  Hernandez-Castillo, Rothwell, G. W., Stockey, R. A., and Mapes, G., ?Growth architecture of Thucydia mahoningensis, a model for primitive walchian conifer plants?, International Journal of Plant Sciences, vol. 164, pp. 443-452, 2003.

G.  Mapes and Rothwell, G. W., ?Structure and relationships of primitive conifers?, Neues Jahrbuch für Geologie und Paläontologie Abhandlungen, vol. 183, no. 1-3, pp. 269-287, 1991.

G. W.  Rothwell and Mapes, G., ?Barthelia furcata gen. nov. et sp. nov., with a review of paleozoique coniferiphytes and a discussion of coniferophyte systematics?, International Journal of Plant Sciences, vol. 162, no. 3, pp. 637-667, 2001.

G. R.  Hernandez-Castillo, Rothwell, G. W., and Mapes, G., ?THUCYDIACEAE Fam. nov., with a review and reevaluation of paleozoic walchian conifers?, International Journal of Plant Sciences, vol. 162, no. 5, pp. 1155-1185, 2001.

G. W.  Rothwell, Mapes, G., and Hernandez-Castillo, G. R., ?Hanskerpia gen. nov. and phylogenetic relationships among the most ancient conifers (Voltziales)?, Taxon, vol. 54, no. 3, pp. 733-750, 2005.