| Noun | 1. | family Cordaitaceae - chiefly Paleozoic plants; Cordaites is the chief and typical genus gymnosperm family - a family of gymnosperms Cordaitales, order Cordaitales - extinct plants having tall arborescent trunks comparable to or more advanced than cycads; known from the Pennsylvanian period; probably extinct since the Mesozoic era Cordaites, genus Cordaites - tall Paleozoic trees superficially resembling modern screw pines; structurally intermediate in some ways between cycads and conifers |