Search

Premise of research. Two permineralized inflorescences have been found in calcium carbonate concretions from the Eocene Appian Way locality on Vancouver Island, British Columbia, increasing sampling density and helping clarify the pattern of phylogeny for Alismatalean monocots. Methodology. Serial sections of specimens were prepared by the cellulose acetate peel technique and studied with light microscopy. Phylogenetic analyses using a morphological matrix of living and fossil Araceae and Acoraceae were performed using TNT version 1.5 to help establish relationships of the fossil inflorescences. Pivotal results. Inflorescences are cylindrical spikes, >37 mm long and 8.1 mm wide, with a peduncle at least 14.5 mm long, bearing numerous helically arranged, bisexual sessile flowers with hooded tepals. Fruits are trilocular, with basal axile placentation and one seed per locule. Remnants of probable stamens are present in most flowers. Conclusions. Flower structure was compared to those of other petalloid, spicate, bisexual flowers in the monocot families Acoraceae and Araceae (Alismatales). The number of carpels is similar to that in Acorus (Acoraceae) and Spathiphyllum (Araceae, Monsteroideae) and some Pothoideae. Single-seeded ovaries are common in Araceae, while the locules in Acorus contain several apically attached seeds. Phylogenetic analyses place Appianospadix in Proto-Araceae near the base of the aroid tree. This inflorescence with a unique combination of characters is described as Appianospadix bogneri , a new genus and species of Alismatales (family: Araceae). [ABSTRACT FROM AUTHOR]

Premise of research. A single cylindrical conifer seed cone has been discovered in a calcium carbonate marine concretion from the Upper Cretaceous Eden Main Quarry, dated as early Coniacian (∼89 Ma), 35 km northwest of Courtenay on Vancouver Island, British Columbia, Canada. Methodology. The specimen was sectioned with a rock saw, and serial sections were prepared using the classical cellulose acetate peel technique. Peel sections were mounted on microscope slides. Reconstructions of the cone and seeds were rendered with Avizo. Pivotal results. The cone is somewhat abraded, at least 2.3 cm long and 1 cm wide, with the apex missing and most of the base coalified. The well-preserved midsection shows bract/scale complexes inserted at a steep angle. The bract/scale complex has a central rhomboidal shaft and two lateral winglike extensions. Xylem of the cone axis is robust, with secondary xylem tracheids that have circular-bordered pits. A single circular vascular trace enters the bract/scale complex. Three resin canals enter the base of the scale and divide to form up to eight or nine canals distally. Six overlapping, inverted winged seeds, ∼8 mm long and 1 mm thick, with two large, fleshy wings are borne on the adaxial surface of each scale. The nucellus is free from the endotesta to its base. Megagametophytes and embryos occur in some seeds. Cells of the megagametophyte have granular contents. This cone shows similarities in overall structure and vasculature to those of living Taiwania (Cupressaceae); however, the fossil cone size is generally larger, with six seeds per scale versus two, and seeds are extremely large and fleshy with a unique submicropylar structure. Conclusions. This cone is compared with living and fossil taxa of Cupressaceae and described as Comoxostrobus rossii gen. et sp. nov. (Cupressaceae subfamily Taiwanioideae), revealing that taiwanioid Cupressaceae were much more diverse and widespread during the Cretaceous. [ABSTRACT FROM AUTHOR]

Premise of research. Five permineralized specimens of infructescences and dispersed fruits assignable to the Altingiaceae have been identified from the Late Cretaceous (Coniacian) Eden Main Quarry on Vancouver Island, British Columbia, Canada. Two infructescences and three isolated two-loculed fruits are preserved in calcium carbonate marine concretions. Methodology. Concretions were sectioned using the cellulose acetate peel technique and were included in a phylogenetic analysis employing morphological characters using TNT. Pivotal results. Infructescences are globose ca. 1 cm in diameter with at least 24 two-loculed fruits and a broad central axis. We have been unable to identify any perianth parts, but there are knob-like extrafloral processes similar to the phyllomes of other altingiaceous infructescences. The inner carpel lining consists of a single palisade layer of elongate rectangular cells. The endocarp also contains several layers of thick-walled, elongate sclerenchyma. The mesocarp is well differentiated, with fiber bundles interspersed with parenchyma and resin canals. There are at least 16 seeds (ovules) per carpel with axile placentation, but most of these are immature or aborted. Fruits have septicidal and ventricidal dehiscence. Specimens are assigned to Protoaltingia comoxense Scharfstein, Stockey & Rothwell gen. et. sp. nov. Conclusions. These fossils represent the second-most ancient occurrence of Altingiaceae, and phylogenetic analysis of morphological characters confirms that P. comoxense is most similar to species of Altingia. Results of morphological analyses resolve Altingia and Liquidambar as sister clades, placing P. comoxense as the basal member of the Altingia clade and sister to Altingia spp., thus documenting that evolutionary diversification of the core eudicot family Altingiaceae (Saxifragales) was well underway by the mid–Upper Cretaceous. [ABSTRACT FROM AUTHOR]