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Citation for Study 229

About Citation title: "Phylogenetic relationships in seed plants.".
About This study was previously identified under the legacy study ID S2x5x96c17c49c16 (Status: Published).

Citation

Crane P. 1985. Phylogenetic relationships in seed plants. Cladistics, 1: 329-348.

Authors

  • Crane P.

Abstract

The phylogenetic relationships of nineteen extant and fossil seed plants are considered. Analysis of 31 characters produced ten topologically similar and equally parsimonious cladograms. A strict consensus tree derived from these cladograms places Lyginopteris as the sister taxon to the other seed plants included. Within this clade all the taxa considered, except medullosans and cycads, form a single monophyletic group defined by the presence of flattened seeds and saccate pollen (platysperms). Relationships between medullosans, cycads, and platysperms were not resolved, but within the platysperm clade conifers and cordaites (Cordaixylon, Mesoxylon) + Ginkgo form a monophyletic group (coniferophytes). The higher platysperms (glossopterids, Caytonia, corystosperms, Bennettitales, Pentoxylon, Gnetales, and angiosperms) are also monophyletic, but their relationship to coniferophytes, peltasperms, and Callistophyton is unresolved. Pentoxylon is placed as sister taxon to the Bennettitales, and together they form the sister group to a clade in which Gnetales and angiosperm are sister taxa. The Bennettitales + Pentoxylon + Gnetales + angiosperms (anthophytes) form a monophyletic sister group to the corystosperms. This analysis is compared with current classifications of seed plants. It does not support a close relationship between Bennettitales and cycads, it provides no evidence for seed plant polyphyly, and it strongly suggests that the current concept of seed ferns has little value in a phylogenetic context.

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  • Canonical resource URI: http://purl.org/phylo/treebase/phylows/study/TB2:S229
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