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Premise of research. Numerous large permineralized fossil seeds from the Jurassic of Haida Gwaii, western Canada, provide evidence for the mode and tempo of cycad evolution. Methodology. Fossil seed specimens are studied from external morphology and serially sectioned by the classic cellulose acetate peel technique to reveal anatomical features of the integument, vascular system, nucellus, and gametophyte. Fossils are compared to living cycad seeds that are also examined from external views, dissections, and anatomical preparations. Pivotal results. The fossil seeds are described as Traskia maahlae gen. et sp. nov. Features of the integument and vascular system reveal that T. maahlae is a stem group cycad that shares seed architecture and mode of germination with living Cycas spp. Conclusions. Traskia maahlae adds to a growing body of paleontological data on stem and crown group cycads. Results suggest that modern pollination and postpollination biology and the two contrasting modes of cycad seed germination evolved during the Mesozoic but that crown group cycad species may not have appeared until the Cenozoic. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Mosses, very diverse in modern ecosystems, are currently underrepresented in the fossil record. For the pre-Cenozoic, fossil mosses are known almost exclusively from compression fossils, while anatomical preservation, which is much more taxonomically informative, is rare. The Lower Cretaceous of Vancouver Island (British Columbia, Canada) hosts a diverse anatomically preserved flora at Apple Bay. While the vascular plant component of the Apple Bay flora has received much attention, the numerous bryophytes identified at the locality have yet to be characterized. METHODS: Fossil moss gametophytes in more than 20 carbonate concretions collected from the Apple Bay locality on Vancouver Island were studied in serial sections prepared using the cellulose acetate peel technique. KEY RESULTS: We describe Tricosta plicata gen. et sp. nov., a pleurocarpous moss with much-branched gametophytes, tricostate plicate leaves, rhizoid-bearing bases, and delicate gametangia (antheridia and archegonia) borne on specialized branches. A new family of hypnanaean mosses, Tricostaceae fam. nov., is recognized based on the novel combination of characters of T. plicata. CONCLUSIONS: Tricosta plicata reveals pleurocarpous moss diversity unaccounted for in extant floras. This new moss adds the first bryophyte component to an already diverse assemblage of vascular plants described from the Early Cretaceous at Apple Bay and, as the oldest representative of the Hypnanae, provides a hard minimum age for the group (136 Ma). [ABSTRACT FROM AUTHOR]

Premise of the study: Two ovulate conifer cones, one of which is attached terminally to a short leafy shoot, reveal the presence of a new species of Hughmillerites in the Early Cretaceous Apple Bay flora of Vancouver Island, British Columbia, Canada. This ancient conifer expands the diversity of Cupressaceae in the Mesozoic and reveals details about the evolution of Subfamily: Cunninghamioideae. • Methods: Specimens were studied from anatomical sections prepared using the cellulose acetate peel technique. • Key results: Vegetative shoots have helically arranged leaves that are CunninghamiaAike. Seed cones have many helically arranged bract/scale complexes in which the bract is larger than the ovuliferous scale. Each ovuliferous scale has three free tips that separate from the bract immediately distal to an inverted seed. Several ovuliferous scales show interseminal ridges between seeds. • Conclusions: This study documents a new extinct species of cunninghamioid conifers, Hughmillerites vancouverensis, expanding the record of the genus from the Late Jurassic to the Early Cretaceous. This new extinct species emphasizes the important role that conifers from subfamily Cunninghamioideae played in the initial evolutionary radiation of Cupressaceae. In light of recent findings in conifer regulatory genetics, we use H. vancouverensis to hypothesize that variations of expression in certain gene homologues played an important role in the evolution of the cupressaceous ovuliferous scale. [ABSTRACT FROM AUTHOR]

Early Cretaceous fossilized leaves assignable to the extinct seed plant order Bennettitales occur within an exceptionally diverse Early Cretaceous (Valanginian) flora of anatomically preserved plant fossils at Apple Bay on Vancouver Island, British Columbia, Canada. One of the bennettitalean leaf types has an entire margin, with laminae that are attached near the adaxial surface of the midvein. Leaves are 10-15 mm wide with an adaxial surface that shows distinct corrugations, and a midrib that is exposed adaxially. The vascular system of the midrib consists of a crescent-shaped ring of collateral bundles. Lateral veins diverge from midrib at ∼90°, are typically simple but occasionally branch at base of the lamina. Vein density is 12-15 per cm. Leaves are hypostomatic with syndetocheilic stomata that are randomly oriented between veins. Internal anatomy consists of an adaxial hypodermis of closely-spaced isodiametric cells, mesophyll that is differentiated into adaxial palisade and abaxial spongy zones, and collateral bundles that show a distinct bundle sheath with bundle sheath extensions. This novel combination of characters represents the diverse bennettitalean genus Nilssoniopteris. Nilssoniopteris corrugata new species is only the second species of the genus for which internal anatomy is preserved. This species increases the known variation of bennettitalean leaf anatomy, and reinforces our appreciation for the global distribution of bennettitalean seed plants during the Mesozoic. [ABSTRACT FROM AUTHOR]

The fossiliferous ironstone deposits of the Upper Cretaceous Horseshoe Canyon Formation in the Drumheller badlands, Alberta, Canada, contain a diverse, anatomically preserved flora. Within this assemblage occur abundant stems, leafy shoots, leaves, ovuliferous cones, and pollen cone clusters that are here described as a new species of Cunninghamia. The stems have persistent leaf bases and plagiotropic branching. Some stems show several growth increments, and the cortex and pith are made up of resin canals, large parenchymatous cells, and lysigenous cavities. Leafy shoot axes have parenchymatous cells, resinous cells, lysigenous cavities, and resin canals within the cortex and pith. The leaves are helically arranged, lanceolate to falcate, with two abaxial stomatal bands, a large central resin canal, and two smaller lateral canals. The ovuliferous cones have numerous helically arranged bract scale complexes. The bracts and three-lobed ovuliferous scale are variously ornamented. Anatomical features of bracts include a well-defined hypodermal layer and resin canals with adaxial traces. A single vascular trace enters the complex and divides to produce the ovuliferous-scale trace and bract traces. Ovules/seeds are ovoid and weakly winged. The pollen cone-bearing branch apices show stalks of at least 17 pollen cones arranged in a pseudowhorl. Each stalk consists of an inflated base surrounded by 5-6 scale-like leaves. The anatomy and morphology of the fossil material agrees so closely with that of modern Cunninghamia that we are confident in describing it as a new species of this genus, Cunninghamia taylorii sp. nov. The present material provides a rare opportunity to contribute toward a better understanding of the specific variation, biology, ecology, and evolutionary history of cunninghamioid Cupressaceae. [ABSTRACT FROM AUTHOR]

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The fossil record of aquatic flowering plants broadens our understanding of their former diversity and origins from terrestrial ancestors. This paper describes a floating aquatic monocot from 71 whole plants and several isolated leaf fragments from Upper Cretaceous oxbow lake sediments in the Dinosaur Park Formation, Alberta, Canada. The new material is represented by rosettes of leaves and roots attached to short stems that are interconnected by stolons and corresponds to the fossil aroid originally described as Pistia corrugata Lesquereux. Up to six plants have been found interconnected on a single slab suggesting that these plants grew in extensive floating mats covering lakes and calm stretches of rivers. Stems have up to six leaves and large numbers of branched aquatic roots. The leaf is trumpet-shaped with an elongate clasping petiole, large aerenchymatous base, and a nearly circular blade rim. Leaf bases are often filled with sediment giving the leaf the appearance of having a basal pouch. Petioles have 6-9 veins that divide into an upper and lower set, and veins converge at an apical notch. A submarginal collective vein and at least two marginal veins with branching veins form the leaf rim. A series of dichotomizing and anastomosing veins characterize the adaxial leaf surface. Tertiary and quatemary veins form polygonal areolae. Leaf surfaces are covered in trichomes that, like those in Pistia stratiotes, probably aided in buoyancy. A reconstruction of the plant is presented. Based on unique leaf morphology, these fossil plants are clearly not assignable to the genus Pistia and are described as Cobbania corrugata (Lesquereux) Stockey, Rothwell et Johnson gen. et comb. nov. Recent systematic analyses using molecular characters resolve two separate origins of floating aquatic aroids included in the duckweeds and the genus Pistia. This new fossil genus increases our understanding of colonization of aquatic habitats by revealing a third possible origin of the floating aquatic habit within Araceae. [ABSTRACT FROM AUTHOR]

Permineralized rhizomes and stipe bases of filicalean ferns occur in the Upper Cretaceous (Campanian) Horseshoe Canyon Formation near the town of Drumheller in southern Alberta, Canada, and these provide an opportunity to describe the first anatomically preserved Mesozoic species of Blechnaceae/Dryopteridaceae. The two new fossil species also provide evidence that modern stelar architecture and stipe anatomy evolved in these families before the end of the Mesozoic. Midlandia nishidae gen. et sp. nov. has an apparently ascending radial rhizome from which stipes diverge in a helical pattern that approaches a 5/8 arrangement. The dictyostele is made up of amphicribral meristeles, and stipe traces consist of two hippocampiform bundles that flank three to four smaller circular bundles. The rhizome of Wessiea oroszii is somewhat smaller, with a dictyostele of five to seven cauline meristeles, from which stipe traces diverge as a pair of hippocampiform bundles. In both species, gaps in the stele are initiated by the divergence of a root trace, whereas stipe traces separate from the sides of the meristeles that flank the gap. The new species show numerous anatomical similarities to living blechnoid and dryopteroid ferns and strongly support hypotheses that these highly derived ferns originated before the Upper Cretaceous. [ABSTRACT FROM AUTHOR]

An anatomically preserved leptosporangiate filicalean that combines characters of the Pteridaceae and tree ferns has been discovered in the Lower Cretaceous (Valanginian-Hauterivian boundary) Apple Bay flora on Vancouver Island, Canada. Exindusiate sori are radial, with numerous annulate sporangia diverging from a conical receptacle that is positioned below a pinnule vein. No paraphyses or other trichomes are present. Sporangia have a nearly vertical annulus that is not interrupted by the long, quadriseriate stalk. Spores are trilete and angular, with a distinctive equatorial flange and a distal deltoid structure that contacts the rim at the corners of the spore. The suture extends three-fourths of the distance to the margin and is flanked by prominent ridges. Spore walls consist of two dense layers, and the surface is psilate. Pterisorus radiata gen. et sp. nov. has characters that are reminiscent of both tree ferns and the most highly derived of modern species, providing direct evidence for the third major radiation of Filicales. [ABSTRACT FROM AUTHOR]

Several fertile pinnules with abaxially borne sporangia have been discovered in calcareous marine nodules from the Middle or Late Eocene Appian Way locality on the east coast of Vancouver Island, British Columbia, Canada. Fertile pinnules are attached in groups of two or three. They are deeply lobed, with each lobe rolled toward the abaxial surface and the entire pinnule rolled toward the abaxial surface to form an irregularly globose structure. Sporangia occur abaxially and form two rows over the entire surface of each pinnule lobe. The midrib of each pinnule lobe is thickened, forming a receptacle from which broadly attached sporangia and numerous paraphyses diverge. As is characteristic of many schizaeaceous ferns, sporangia of the fossil are flask shaped with a short stalk and have a uniseriate, transverse annulus at the apex. Spores are tetrahedral and trilete, like those of the type species for the extinct genus Paralygodium. The new specimens are described as Paralygodium vancouverensis sp. nov. and are compared to both living genera of schizaeaceous ferns and the extinct species Paralygodium yezoense and Anemia poolensis. The unique combination of characters displayed by each of the fossil species reveals the presence of several extinct schizaeaceous lineages and supports interpretations that the diversity of Schizaeaceae s.l. was greater during the Cretaceous and Paleogene than it is today. [ABSTRACT FROM AUTHOR]

Permineralized cyatheaceous sori occur among remains of conifers, fungi, and other plants in newly discovered calcareous concretions from Early Cretaceous (Barremian) marine sediments of Vancouver Island, British Columbia, Canada. Sori are superficially attached in two rows to narrow pinnules and display a globose sphaeropteroid indusium. Annulate sporangia with multicellular stalks diverge from a basal, vascularized receptacle. The nearly vertical uniseriate annulus is not interrupted by the stalk. The sporangia bear 64 trilete spores with perispore sculpturing that ranges from irregular granulate/echinate to prominent rodlets. These specimens, described as Cyathea cranhamii sp. nov., are the first anatomically preserved tree fern sori from the fossil record. They represent the most ancient evidence for fertile structures of the Cyatheaceae and demonstrate that essentially modern species of cyatheaceous tree ferns had evolved by the Early Cretaceous. [ABSTRACT FROM AUTHOR]

Describes more than 10,000 Metasequoia-like compression specimens from two localities in Canada. Assessment of specific identity of specimens using collection of specimens to reveal existence of M. foxii sp. nov., a previously unrecognized species; Plant anatomy and morphoology; Characters of species of Metasequioa.

Evaluates the features of Osmunda cinnamomea from the Upper Cretaceous Horseshoe Canyon Formation in southern Alberta and other permineralized O. cinnamomea-like fossils. Fossils' conformity to the living species; Hypothesis that species longevity in homosporous pteridophytes may be far greater than commonly recognized; Example of a fossil filicalean fern.

Reports on fossil ectomycorrhizae from the British Columbia. Effects of hormones produced by living ectomycorrhizal fungi; Evolution of mycorrhizal associations; Features of the Princeton chert fossils; Characterizations of the mycorrhizal rootlets.

In addition to having a rich assemblage of mammalian fossils, the Gao Mine locality in the Paskapoo Formation of south-central Alberta has yielded numerous plant specimens of late Paleocene (late Tiffanian or Ti5) age. The plant fossils are preserved in siltstones and fine-grained sandstones interpreted as overbank sediments that were deposited on an aggrading floodplain. The assemblage is dominated by the cupressaceous conifer Metasequoia foxii and the cercidiphyllaceous dicot Joffrea speirsiae, including their well-preserved seedlings. The flora also contains foliage of the ferns Onoclea and Speirseopteris and the woody dicots Palaeocarpinus, Aphananthe/ Celtis , Aesculus, Beringiaphyllum, ? Trochodendron, and Wardiaphyllum, as well as seedlings of unknown dicotyledonous angiosperms. Metasequoia foxii and Speirseopteris are unique to the floras of Gao Mine and the nearby Munce's Hill site (Tiffanian Ti4). The remainder of the taxa are common in late Paleocene floras of North Dakota, Montana, and Wyoming, all USA. The floras of the nearby Joffre Bridge Roadcut and Blindman River sites (both Tiffanian Ti3) are more diverse, but both of those sites encompass a wider range of depositional environments and may include higher percentages of allochthonous material. Most of the Gao Mine material is autochthonous. The seedlings were buried in place, along with the surrounding leaf litter, preserving a record of the local plant community. [ABSTRACT FROM AUTHOR]