Beck, Charles B. Department of Molecular, Cellular, and Development Biology, University of Michigan, Ann Arbor, Michigan.
Last reviewed:January 2020
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A class of largely extinct gymnosperms (Pinophyta). Included orders are Calamopityales, Callistophytales, Arberiales, Peltaspermales, Ginkgoales, Leptostrobales, Caytoniales, Pentoxylales, and Ephedrales. The most ancient taxa, Calamopityales and Callistophytales, lived during the Carboniferous; the Arberiales, from late Carboniferous into the Triassic; the Peltaspermales, from Permian through Jurassic; the Leptostrobales and Caytoniales, from Triassic into the Cretaceous; and Ginkgoales, predominantly, from Triassic into the Cretaceous periods, with one species, Ginkgo biloba, persisting to the present. Ephedrales is the only largely extant group, but has a pollen fossil record beginning in the Upper Triassic. See also: Caytoniales; Ephedrales; Ginkgoales
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