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Hanskerpia gen. nov. and phylogenetic relationships among the most ancient conifers (Voltziales)
Numerical cladistic analysis reveals that this novel combination of characters defines a new fossil plant genus and species of walchian conifers Hanskerpia hamiltonensis, and supports some previously proposed relationships among the most primitive conifer and other Paleozoic coniferophytes. Expand
The fossil monocot Limnobiophyllum scutatum: resolving the phylogeny of Lemnaceae.
Results of the analysis indicate that the Lemnaceae plus Pistia form a monophyletic group within the Araceae, and relationships among taxa of the Lemmaceae, Pistia, and selected genera of Araceae are resolved. Expand
Characterizing the Most Primitive Seed Ferns. I. A Reconstruction of Elkinsia polymorpha
Elkinsia polymorpha is the first seed f Fern to be reconstructed from Devonian sediments and the first preovulate seed fern to be characterized as a plant, and represents an important evolutionary unit for ongoing phylogenetic studies of the origin of seed plants. Expand
Fossil ectomycorrhizae from the Middle Eocene.
These exquisitely preserved specimens represent the first unequivocal occurrence of fossil ectomycorrhizae and demonstrate that such associations were well-established at least 50 million years ago. Expand
Elkinsia gen. nov., a Late Devonian Gymnosperm with Cupulate Ovules
An extensive collection of fossilized ovules, ovulate cupules, and cupuliferous branching systems from late Devonian deposits of eastern West Virginia is described and named Elkinsia polymorpha gen.Expand
The callistophytales (Pteridospermopsida): Reproductively sophisticated paleozoic gymnosperms
An Anatomically preserved reproductive organs of the major groups of Paleozoic gymnosperms are compared, and a closer than currently recognized relationship of paleozoic seed plants is proposed. Expand
An herbaceous fossil conifer: Gymnospermous ruderals in the evolution of Mesozoic vegetation
Abstract Fast growing conifers have been recognized in disturbed habitats of the transitional Lower Middle Triassic Gres a Voltzia delta from the Buntsandstein in eastern France. These herbaceousExpand
Todea from the Lower Cretaceous of western North America: implications for the phylogeny, systematics, and evolution of modern Osmundaceae.
Fossil evidence confirms that Osmundaceae originated in the Southern Hemisphere during the Permian, underwent rapid diversification, and species extended around the world during the Triassic, and that the genus Todea evolved by the Lower Cretaceous. Expand