^Cycadophyta, Ginkgophyta, Gnetophyta, and Pinophyta (also known as Coniferophyta) phyla are still in existence while those in the Pteridospermales and Cordaitales phyla are now extinct.
^Yang, Yong. An updated red list assessment of gymnosperms from China (Version 2021). Biodiversity Science. 2021-12-20,29 (12): 1599.doi:10.17520/biods.2021342.
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Soltis, Douglas E., Pamela S. Soltis and Michael J. Zanis. 2002. Phylogeny of seed plants based on evidence from eight genes.American Journal of Botany 89: 1670-1681 (abstract).
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