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A new Triassic corystosperm is described from the Shackleton Glacier region of Antarctica. The compression fossils include cupulate organs (Umkomasia uniramia) and leaves (Dicroidium odontopteroides) attached to short shoot-bearing branches. The cupulate organs occur in groups near the apices of the short shoots, and each consists of a single axis with a pair of bracts and a subapical whorl of five to eight ovoid cupules. This unique architecture indicates that the cupules are individual megasporophylls rather than leaflets of a compound megasporophyll. A branch bearing an attached D. odontopteroides leaf provides the first unequivocal evidence that Umkomasia cupulate organs and Dicroidium leaves were produced by the same plants. Although this had previously been assumed based on organ associations, the new specimens are important in demonstrating that a single species of corystosperm produced the unique cupulate organs described here and the geographically and stratigraphically widespread and common D. odontopteroides leaf. Therefore, biostratigraphic, paleoecological, and phylogenetic studies that treat Dicroidium leaf morphospecies as proxies for biological species of entire plants should be reconsidered. Phylogenetic analysis suggests that the corystosperm cupule is an unlikely homologue for the angiosperm carpel or outer integument.

Permineralized leaves of the Triassic podocarpaceous conifer Notophytum krauselii are described from the Fremouw Formation of Antarctica. The leaves are elongate and apetiolate with 8-12 parallel veins. The adaxial epidermis consists of rows of rectangular to pentagonal cells; the abaxial epidermis is papillate. Longitudinally oriented stomata occur on both surfaces. An adaxial palisade layer is present and auxiliary sclereids are common in the mesophyll. The vascular bundles have a weakly defined sheath and are flanked by transfusion tracheids. Bundles in the basipetal area of the leaf are capped by sclerotic tissue and subtended by resin canals. These leaves are superficially similar to those of the extant podocarp genus Nageia, but probably represent a distinct acquisition of this leaf type within the Podocarpaceae. Notophytum leaves are similar to the common compression fossil Heidiphyllum elongatum and may be closely related or even conspecific. Evidence from Antarctica suggests that Heidiphyllum and the seed cone Telemachus were produced by the same plant, and may be closely related to several other early Mesozoic conifers with multiveined leaves.

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We present a whole-plant concept for a genus of voltzialean conifers on the basis of compression/impression and permineralized material from the Triassic of Antarctica. The reconstruction of the individual organs is based on a combination of organic connections, structural correspondences, similarities in cuticles and epidermal morphologies, co-occurrence data, and ex situ palynology. The affiliated genera of organs include trunks, branches, and roots (Notophytum); strap-shaped leaves with parallel venation (Heidiphyllum compressions and permineralized Notophytum leaves); seed cones (Telemachus and Parasciadopitys); pollen cones (Switzianthus); and bisaccate pollen of Alisporites type. Structural similarities lead us to suggest that Parasciadopitys is the permineralized state of a Telemachus cone and should be treated as a junior synonym. Biotic interactions involving the reconstructed conifer genus include plant-insect interactions (oviposition by Odonata) and not less than five different types of plant-fungal interactions, including two distinct endomycorrhizal associations, two probable seed parasites, and epiphyllous fungi. A representative whole plant is reconstructed as a 10-15-m-tall, seasonally deciduous forest tree with a vertical, narrow-conical crown shape. We interpret these Telemachus trees as the dominant components of peat-forming conifer swamps, forest bogs, and immature bottomland vegetation in the Triassic high-latitude river basins of southern Gondwana. In architecture, growth habit, and many ecological characteristics, the Telemachus conifers appear to be comparable to extant larch (Larix). Owing to the large amount and often exquisite preservation of the material, this conceptual whole-plant genus represents one of the most completely reconstructed ancient conifer taxa to date.

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Modern cladistic analyses support earlier suggestions that the Hymenophyllaceae (the "filmy ferns") are basal filicaleans. However, the fossil record of the family is ambiguous. A new fossil fern, Hopetedia praetermissa gen. et sp. nov., from the Upper Triassic Pekin Formation of North Carolina (USA), is described and interpreted as the oldest unequivocal representative of the Hymenophyllaceae based primarily on general frond morphology, indirect evidence for a filmy (membranaceous) habit, and soral position and morphology. Particularly compelling as evidence for the hymenophyllaceous affinity of H. praetermissa is the funneliform structure of the indusium (involucre), which is similar to that found primarilly in the extant Trichomanes (sensu lato) clade. However, the receptacle in H. praetermissa is relatively short and, thus, more like most representatives of the Hymenophyllum (sensu lato) clade. The Triassic age of this fossil is consistent with the basal or near basal position of the Hymenophyllaceae in all recent phylogenetic analyses of the filicalean ferns. Hopetedia preatermissa is evaluated in relationship to several previous reports of fossil Hymenophyllaceae.