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The gymnosperms (/ ˈ dʒ ɪ m n ə ˌ s p ɜːr m z,-n oʊ-/ ⓘ nə-spurmz, -noh-; lit. ' revealed seeds ') are a group of woody, perennial seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae [2] The term gymnosperm comes from the ...
The tree-like Archaeopteris, ancestral to the gymnosperms, and the giant cladoxylopsid trees had true wood. These are the oldest known trees of the world's first forests. Prototaxites was the fruiting body of an enormous fungus that stood more than 8 meters tall. By the end of the Devonian, the first seed-forming plants had appeared.
The fungi were of the phylum Glomeromycota, [39] a group that probably first appeared 1 billion years ago and still forms arbuscular mycorrhizal associations today with all major land plant groups from bryophytes to pteridophytes, gymnosperms and angiosperms and with more than 80% of vascular plants.
However, angiosperms appear suddenly and in great diversity in the fossil record in the Early Cretaceous (~130 mya). [48] [49] Claimed records of flowering plants prior to this are not widely accepted. [50] Molecular evidence suggests that the ancestors of angiosperms diverged from the gymnosperms during the late Devonian, about 365 million ...
The gymnosperms consist of five orders of seed plants: Cupressales, Cycadales, Ginkgoales, Gnetales and Pinales. [a] They developed more than 350 million years ago, long before flowering plants, according to the fossil record. The name comes from the Greek for "naked seed"; the egg cells are not protected by ovaries, as in flowering plants. [4]
Ginkgo sperm were first discovered by the Japanese botanist Sakugoro Hirase in 1896. [28] The sperm have a complex multi-layered structure, which is a continuous belt of basal bodies that form the base of several thousand flagella which have a cilia-like motion.
The first mammals also appeared during the Mesozoic, but would remain small—less than 15 kg (33 lb)—until the Cenozoic. Flowering plants appeared in the Early Cretaceous and would rapidly diversify through the end of the era, replacing conifers and other gymnosperms ( sensu lato ), such as ginkgoales , cycads and bennettitales as the ...
Ginkgo is a genus of non-flowering seed plants, assigned to the gymnosperms.The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, [3, and Ginkgo is now the only living genus within the order.