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Anatomically preserved lycophytes of the Lycopodiales and Selaginellales have been discovered among a diverse assemblage of plants and fungi in carbonate marine concretions at the Apple Bay locality along the shore of Holbert Inlet near the northern end of Vancouver Island, British Columbia, Canada. Lycopodialean stems are plectostelic and actinostelic, branch dichotomously, and are similar to both Lycopodicaulis oellgaardii and Lycoxylon spp. The Selaginella specimens represent the first anatomically preserved Selaginellales with excellent internal cellular preservation in the fossil record, and are described as Selaginella quatsinoense Rothwell et Stockey sp. nov. Stems have three and five exarch, monarch stelar segments, each of which is surrounded by an aerenchymatous endodermis with trabeculae. The leaf base is indented on the adaxial surface, suggesting the position of a ligule. These fossils document that species with diagnostic internal anatomy of modern Lycopodiales and Selaginellales evolved no later than the Valanginian of the early Cretaceous. [ABSTRACT FROM AUTHOR]

Premise of research. Ten anatomically preserved conifer seed cone specimens are preserved on the surfaces of, and within, three interlocking rock fragments of terrestrial limestone discovered as float along the Colville River on the North Slope of Alaska, providing additional evidence for the diversification of taiwanioid Cupressaceae during the Upper Cretaceous–Cenozoic interval. Methodology. Specimens on rock surfaces were measured and photographed, and then serial anatomical thin sections were prepared by the cellulose acetate peel technique. Three-dimensional images of selected specimens were also captured using micro–computed tomography (micro-CT). Pivotal results. The structure of these seed cones is similar to that of living Taiwania cryptomerioides in cone shape, the presence of subtending scalelike leaves, helically arranged and imbricating foliate ovuliferous complexes (OCs), the absence of a separate ovuliferous scale tip, variation in numbers of OCs, and by having two adaxially positioned winged seeds per complex. However, abruptly upturned OC, details of OC vasculature, and distinctive histological features reveal that these seed cones represent a new species of the extinct genus Mukawastrobus. Conclusions. When added to the existing record of fossil seed cones, the new species Mukawastrobus arnoldii highlights the recent discovery that among early-diverging lineages of Cupressaceae, there has been considerable Cretaceous, Paleogene, and Neogene evolution that is reflected by variations among subtle characters that are not recognizable in any but the most completely preserved specimens. [ABSTRACT FROM AUTHOR]

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. 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 research. The Late Cretaceous Yezo Group in Hokkaido, Japan, yields abundant plant debris in calcareous concretions. Nearly 150 species of plants have been described since 1910. Here we add a new genus of a probable stem polypodioid leptosporangiate fern to the plants of the Yezo Group based on a permineralized fertile pinnule from the Mikasa locality. Methodology. The fertile pinnule was detected in a calcareous concretion as an X-ray computed tomography image. Specimens were studied from serial cellulose acetate peels. Three-dimensional reconstructions of the entire pinnule and the soral, sporangial, and indusial morphologies were rendered using Molcer Plus and Amira. Pivotal results. The pinnule is 11.7 mm long, less than 7 mm wide, and deeply pinnatisect, with an abaxially grooved midrib or "costule" bearing one terminal and six lateral segments with catadromic pinnate venation. Lateral veins are simple or bifurcate once near the segment margin. The sorus is indusiate and abaxial and occurs slightly proximal to the end of the single vein or, when the lateral vein bifurcates, near the end of a much shorter anadromic vein. The indusium is reniform, is attached close to a massive receptacle only at its base, and is not laterally fused with the lamina. Approximately 17 sporangia with a slightly oblique, incomplete annulus, each estimated to contain ca. 64 spores, are formed per sorus. Spores are tetrahedral and trilete, have a triangular amb and slightly convex sides, are 42–45 μm in equatorial diameter, have a smooth exine, and are comparable to Biretisporites -type dispersed spores. Conclusions. The unique characters of the fossil are shared separately by extant basal polypods, most abundantly in Dennstaedtiaceae. However, the oblique annulus of the fossil does not occur in any extant members of Polypodiales unless it appears homoplastically. We therefore describe the fossil as a new taxon of a probable stem polypod, Mikasapteris rothwellii gen. et sp. nov., without any order and family assignments. The presence of Mikasapteris during the Late Cretaceous shows that pre-Polypodiales ferns were more diverse during this period. [ABSTRACT FROM AUTHOR]

Premise of research. Sixteen compression/impression specimens of a new floating aquatic angiosperm that enrich our knowledge of Late Cretaceous vegetation have been identified from the early Maastrichtian St. Mary River Formation near Cardston, Alberta, Canada. Methodology. Fossils were studied using dégagement and photographed under reflected light. Leaves were morphotyped using methodology in the Manual of Leaf Architecture and compared to other extant and extinct rosette-forming floating aquatic angiosperms. Pivotal results. Stems of this aquatic dicot show determinate growth of floating shoots with opposite/decussate attachment of heterophyllous leaves. Leaves are simple and sessile at the apicalmost node, simple and petiolate at the second node, and compound with three leaflets at nodes 3–6. Compound leaves are petiolate and ternate (trifoliate). Leaflet shape is unlobed, obovate, and symmetrical; base is acute-obtuse; apex angle is obtuse; base shape is convex; petiolar attachment is marginal; apex shape is rounded; and margin is crenate. Primary veins are flabellate to pinnate with three to five basal veins that dichotomize distally. Secondary veins are craspedodromous with uniform spacing and angles. Teeth are of a single order, three per centimeter near apex, and convex-convex; the sinus is angular, and the apex is foraminate. Conclusions. While the basic growth habit of this plant is similar to that of several extant taxa in the Onagraceae, Lythraceae, Plantaginaceae, and Hydrocharitaceae, leaf venation and the presence of compound leaves differ greatly from the living species. In growth habit and the presence of both simple and compound leaves, the new plant is similar to Quereuxia angulata , also found at this fossil site. These fossils are described as a new genus and species, Tolmania aquatica Edmonds, Stockey & Rothwell, which differs from Quereuxia in pattern of heterophylly, venation, larger plant size, stem morphology, and the presence of hydathodes in the leaves. [ABSTRACT FROM AUTHOR]

Anatomically preserved fossil gleicheniaceous fern remains in carbonate marine concretions from Vancouver Island, British Columbia, Canada support the development of a whole plant concept for an Eocene species of Gleichenia , and provide data to develop the first organismal concept for an extinct species of Gleichenia from the Cenozoic fossil record. New information for completing the plant reconstruction includes anatomically preserved pinnule fragments with attached radial exindusinate sori of six to seven annulate sporangia containing trilete spores. While the overall pattern of evolution within Gleicheniaceae remains incompletely understood because well-documented fossils from pre-Cretaceous deposits are inconsistently preserved, this organismal plant concept strengthens evidence that all diagnostic features of the family Gleicheniaceae were present, and that essentially modern species were well-established and diversifying during the Cretaceous and Paleogene. • First whole plant reconstruction of a Cenozoic species of Gleichenia. • Characterized by both external morphology and internal anatomy. • Evidence of stems, frond fragments, and sori of sporangia containing spores. • Essentially modern species of Gleicheniaceae evolved no later than the Paleogene. • Family Gleicheniaceae is inconclusively present in pre-Cretaceous deposits. [ABSTRACT FROM AUTHOR]

Premise of research. Mesozoic to Cenozoic fungi forming scutella, shield-like coverings of sporulating tissue on leaf surfaces, offer insights into the diversification of filamentous ascomycetes. We found a new fungal sporocarp type consisting of radiate scutella growing from the stomata of leaves of a conifer in a survey of dispersed plant cuticles from the Lower Cretaceous of Virginia. Here, we interpret the new morphotype and compare it with other fossil groups and with extant taxa. Methodology. We isolated fragments of conifer cuticles colonized by the fungus from macerated clays of the Potomac Group, lower Zone 1 (Aptian, 125–113 Ma), and studied them using light microscopy. We analyzed the anatomy of scutella of living taxa and compared the fossils with extant taxa producing either rhizothyria, asexual sporocarps that release spores from below the outer edge of the scutellum, or thyriothecia, sporocarps that release spores through dorsal cracks or an ostiole. Pivotal results. Stomatothyrium placocentrum gen. et sp. nov. has a radial arrangement of scutellum hyphae, characteristic of extant and fossil thyriothecial species in Dothideomycetes (Ascomycota). The scutella develop cracks on the dorsal surface that may show the dehiscence mechanism. Unusually for dehiscence in Dothideomycetes, the cracks follow the scutellum circumference rather than its radius. Each scutellum arises from a host plant stoma, appearing first as a hyphal columella that broadens into a flat scutellum disk on the leaf surface. The morphotype is common, and we found more than 63 specimens at different developmental stages on cuticle fragments. Conclusions. Its unique morphology suggests that S. placocentrum gen. et sp. nov. represents a now extinct group of leaf-dwelling Dothideomycetes that formed thyriothecia. This discovery contributes to our understanding of the range of character combinations of early epiphyllous Ascomycota. [ABSTRACT FROM AUTHOR]

Premise: Nearly 200 araceous leaves and two spadices have been identified among Paleocene fossils from the Blindman River locality near Blackfalds, Alberta, Canada. Although not found in attachment, these probably represent parts of the same extinct plant species. Methods: Specimens were studied using light microscopy. Phylogenetic analyses using a morphological matrix of living and fossil Araceae were performed using TNT version 1.5 to help establish relationships of the fossil leaves and spadices within Araceae and to each other. Results: Leaves are simple with a broad petiole, entire margin, and elliptic to ovate or oblong blade with an acute to slightly rounded apex. A multi‐veined midrib extends into the basal region of the blade. Parallelodromous primary veins of two orders diverge at acute angles, converging with a submarginal vein or at the apex. Transverse veins are opposite percurrent, producing rectangular to polygonal areoles. Higher‐order veins are mixed opposite/alternate. Spadices are cylindrical, with helically arranged, bisexual, perigoniate flowers, each with six free tepals and a protruding style. Fruits are trilocular, with axile placentation and one seed per locule. Conclusions: Leaves are assignable to the fossil genus Orontiophyllum J. Kvaček & S.Y. Sm. as O. grandifolium comb. nov. Spadices are described as Bognerospadix speirsiae gen. et sp. nov. Leaves and spadices each conform to an early‐diverging lineage of Araceae, increasing the known diversity of Proto‐Araceae (viz., subfamilies Gymnostachydoideae and Orontioideae). Together, they provide strong evidence for extinct Proto‐Araceae with novel combinations of characters shortly after the Cretaceous‐Paleogene floral transition. [ABSTRACT FROM AUTHOR]

PREMISE: Fossils can reveal long‐vanished characters that inform inferences about the timing and patterns of diversification of living fungi. Through analyzing well‐preserved fossil scutella, shield‐like covers of fungal sporocarps, we describe a new taxon of early Dothideomycetes with a combination of characters unknown among extant taxa. METHODS: Macerated clays from the Potomac Group, lower Zone 1, from the Lower Cretaceous (Aptian, 125–113 Ma) of Virginia USA yielded one gymnospermous leaf cuticle colonized by 21 sporocarps of a single fungal morphotype. We inferred a tree from nuclear ribosomal DNA of extant species, and coded morphological characters to evaluate alternative, equally parsimonious placements of the fossil in a molecular constraint tree of extant species. RESULTS: Bleximothyrium ostiolatum gen. et sp. nov. has an ostiolate scutellum of radiate, dichotomizing hyphae. Unlike otherwise similar extant and fossil taxa, B. ostiolatum has tangled hyphae at its scutellum margin. Scutella of B. ostiolatum are connected to superficial mycelium, to intercalary and lateral appressoria, and to extensive subcuticular "mycélium en palmettes". The gymnospermous host has characters consistent with identity as a non‐papillate ginkgophyte or cycad. CONCLUSIONS: Bleximothyrium ostiolatum is the oldest known fossil fly‐speck fungus that occurs on plant cuticles and has the radiate, ostiolate scutellum known only from Dothideomycetes. Its combination of characters, its scutellum margin, and mycélium en palmettes are unknown in other extant and fossil species, and Bleximothyrium ostiolatum likely represents a new group of fly‐speck fungi that may now be extinct. [ABSTRACT FROM AUTHOR]

A single cylindrical seed cone 2 cm long, 1.1 cm wide has been found preserved in a calcium carbonate marine concretion from the Hakobuchi Formation (late Campanian-early Maastrichtian) of Hobetsu, Hokkaido, Japan. The cone, attached to a bent peduncle lacking leaves, has helically arranged bract/scale complexes that arise at right angles from the cone axis in the middle of the cone. The cone axis, ca. 1 mm wide, has a broad cylinder of secondary vascular tissue, and lacks a continuous resin canal system. Bract-scale complexes are laminar, cordate-orbiculate, and upturned distally, consisting primarily of bract tissue with no visible scale tip. The vascular trace to the bract/scale complex originates as a rod that divides laterally into several traces at the level of seed attachment. A single resin canal originates at the base of the bract-scale complex abaxial to the vascular strand, but more distally there are up to ca. 15 large resin canals that form a single row. Two to three inverted winged seeds are attached adaxially near the cone periphery. Cone structure and vascularization are most similar to those in the Cupressaceae, Subfamily Taiwanioideae, differing from living Taiwania cryptomerioides by having up to three seeds/scale rather than two, an abruptly upturned bract tip, in details of bract/scale vasculature, and a cone peduncle lacking leaves. This cone is described as Mukawastrobus satoi Stockey, Nishida and Rothwell. Together with previously described Early to Late Cretaceous taiwanioid seed cones from Mongolia and Hokkaido the new species demonstrates that the taxonomically diagnostic characters of such conifers are as subtle as those of Cretaceous and Cenozoic sequoioid Cupressaceae. This realization emphasizes that evolutionary diversification and turnover among taiwanioid conifers during the Cretaceous and Paleogene are probably far greater than currently recognized. [ABSTRACT FROM AUTHOR]

Premise: Exceptional anatomical preservation of a fossil araucarian seed cone from a marine carbonate concretion from Vancouver Island, British Columbia, Canada provides unusually complete evidence for cone structure including seeds, megagametophytes, microgametophytes, and embryos of an Upper Cretaceous (Campanian) species of Araucaria, providing important new insights into the structure and relationships of Cretaceous Northern Hemisphere Araucariaceae. Methods: The cone was studied from serial thin sections prepared by the coal ball peel technique. Phylogenetic analysis using a modified morphological matrix with both discrete and continuous characters was performed using TNT version 1.5. Results: The nearly spherical cone, 6 × 6 cm in diameter, has helically arranged cone‐scale complexes, consisting of a large bract with an upturned tip and a small, fleshy ovuliferous scale. Vascularization of the cone‐scale complex is single at its origin. Widely winged bracts, with a bulging base, contain numerous vascular bundles, interspersed with transfusion tissue, and a large number of resin canals. Seeds are ovoid, 1.2 cm long, 1.2 cm in diameter. Nucellus is free from the integument, except at its base, with a convoluted apex, containing possible pollen tubes. Megagametophytes and mature cellular embryos occur in several seeds. Conclusions: This small cone with attached, imbricate leaves, wide bracts, and unusually large seeds, most closely resembles those of Araucaria Section Eutacta. Width and continuity of secondary xylem in the cone axis, and intact cone‐scale complexes indicate that this cone probably did not disarticulate readily at maturity. When added to a modified, previously published phylogenetic analysis, Araucaria famii sp. nov. enhances our understanding of the Cretaceous radiation of Northern Hemisphere Araucaria Section Eutacta. [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]

Fly-speck fungi reproduce via thyriothecia that consist of sporogenous tissue appressed to cuticle surfaces of plant leaves and covered by a shield-like scutellum. Thyriothecial scutella likely evolved repeatedly in Dothideomycetes (Ascomycota), and their morphology varies by lineage. Fly-speck fungi have an exceptionally good fossil record that begins in the Mesozoic. The interpretation of scutellum characters in fossils may provide insights into origins of Dothideomycetes and help calibrate the timing of ascomycete evolution. From sediments of the Lower Cretaceous (125–112 Ma) Potomac Group of Virginia, from Dutch Gap Canal, lower Zone 1, we found scutella similar to those of extant Aulographaceae (Dothideomycetes), attached to a single piece of dispersed coniferous cuticle. We analyze hyphae and scutellum development among four extant Aulographaceae species for comparison with the fossil. The excellent preservation of fungi on the leaf cuticle surface allows us to infer a developmental sequence for the fossil. Scutellum development begins with coordinated growth of multiple neighboring generator hyphae and continues with hyphae producing two-dimensional pseudomonopodial, dichotomous, radial growth. Asci and ascospores were not found. We coded states for seven morphological characters using direct observations of the fossil and eight extant taxa, and using the literature for 28 others. We inferred a phylogeny using nuclear 18S and 28S rDNA of 36 extant taxa, 34 Dothideomycetes and two Arthoniomycetes. The phylogeny includes newly determined sequences from five species, two from Aulographaceae. With a branch-and-bound search, we inferred the most parsimonious placements of the fossil given the molecular tree topology. The parsimony analysis constrained by the rDNA phylogeny places the fossil taxon among stem lineages near Aulographaceae or among the known living members of Aulographaceae. We describe the fossil morphotype as Protographum luttrellii, gen. et sp. nov. The fossil provides the oldest evidence of morphological characters restricted among extant fungi to Aulographaceae. [ABSTRACT FROM AUTHOR]

Premise of research. Four small pollen cones bearing pollen have been found attached to a leafy twig in a calcareous concretion from the Valanginian Apple Bay locality, northern Vancouver Island, British Columbia, increasing the known morphological diversity of Early Cretaceous cupressaceous pollen cones.Methodology. Specimens were prepared using the cellulose acetate peel technique, pollen was examined using SEM, and three-dimensional reconstructions were rendered with Avizo.Pivotal results. The small, subglobose cones bear helically arranged microsporophylls with a central resin canal. Each sporophyll bears three abaxial pollen sacs. Walls of pollen sacs are comprised of radially elongated rectangular cells with prominent wall thickenings. Most pollen sacs are intact and contain numerous, nonsaccate pollen grains. Pollen is 16-24 μm in diameter with one exit papilla that forms a low protuberance on the grain. External surfaces of grains are scabrate with numerous orbicules and macrogranules, and the nexine is laminated. Cone and pollen morphology most closely resemble taxa of the taxodioid Cupressaceae. The number of pollen sacs per microsporophyll is similar to Athrotaxis, Metasequoia, Sequoia, Sequoiadendron, and the Paleogene fossil conifer Homalcoia. Arrangement of cones on branches differs from those of Athrotaxis, Metasequoia, and Homalcoia; pollen lacks the long distal papilla of Sequoia and Sequoiadendron and is most similar in size to that in some cupressoid Cupressaceae in Chamaecyparis, Thuja, and Juniperus but with a smaller aperture.Conclusions. This combination of features is unlike that found in any living or extinct species of Cupressaceae. The fossil species is described as Morinostrobus holbergensis gen. et sp. nov., furthering our understanding of character evolution within Cupressaceae s.l. and adding to the evidence that the Lower Cretaceous was a time of increasing cupressaceous diversity. [ABSTRACT FROM AUTHOR]

Premise of research. Two permineralized fruits have been found within a single calcareous concretion from the Upper Cretaceous (upper Campanian) Spray Formation of Vancouver Island, British Columbia. These fossils provide additional evidence for the initial phylogenetic diversification of Cornales, the earliest diverging asterid lineage. Methodology. Specimens were prepared using the cellulose acetate peel technique. Pivotal results. A new cornalean species, Suciacarpa xiangae sp. nov., is characterized on the basis of a wellpreserved fruit specimen. This fruit is represented by a large ovoid tetralocular sclerenchymatous endocarp. Locules are crescent shaped in transverse section and accompanied by short dorsal germination valves. Valves consist of small isodiametric sclereids as well as a large number of large secretory cavities. The septum and central axis are composed of transversely oriented and interwoven fibers and elongate sclereids. There is no major central vascular bundle; however, there are numerous small bundles scattered within the septa. This fruit has one apically attached seed per locule. An additional cornalean taxon--Sheltercarpa vancouverensis gen. et sp. nov., also represented by a single smooth tetralocular sclerenchymatous endocarp--consists of isodiametric and a few elongate sclereids, with short germination valves, one seed per locule, and lacks a central vascular bundle. Conclusions. Because of unique combinations of characters, the two fruits described in this study represent two new cornalean taxa, S. xiangae sp. nov. and S. vancouverensis gen. et sp. nov. These fruits display mosaics of apomorphic and plesiomorphic characters that occur in families of at least two different major cornalean clades: Cornaceae/Alangiaceae and Nyssaceae/Mastixiaceae/Davidiaceae. The morphological diversity seen in these taxa and other cornaleans from the Late Cretaceous suggests that the Campanian was an important time for the initial phylogenetic diversification of Cornales. [ABSTRACT FROM AUTHOR]

Premise of research. Early Cretaceous (Valanginian) rocks exposed at Apple Bay (Vancouver Island, Canada) have yielded numerous anatomically preserved bryophytes that have expanded our knowledge of the pre-Cenozoic fossil record of this group. A new moss type with tricostate leaves from Apple Bay combines characters not encountered in moss species recorded previously, warranting in-depth characterization of a new taxon. Methodology. Carbonate concretions containing permineralized fossil material were sectioned using the cellulose acetate peel technique. The resulting acetate peels providing serial sections through the bryophyte specimens were used to reconstruct the habit of the plant and its leaves in two and three dimensions. Pivotal results. We describe a new species of moss in the family Tricostaceae, Tricosta priapiana sp. nov. The anatomy and morphology of the new species justify expanding and refining the diagnoses of Tricostaceae and Tricosta , especially with respect to perigonial branches and the morphology of branch buds. The presence of pseudoparaphyllia surrounding the branch buds supports the pleurocarpous affinities proposed previously for the Tricostaceae. Conclusions. Tricosta priapiana adds to the diversity of tricostate mosses, an extinct group that was intriguingly diverse in the Mesozoic. Nevertheless, the tricostate state is probably a convergent trait, or a trait that may have evolved independently in acrocarpous and pleurocarpous moss lineages in response to similar selective pressures. Still, it remains unclear what such selective pressures may have been, as the paleoclimates and habitats that hosted the tricostate mosses are not well circumscribed, precluding comparisons among the different species and their closest analogs among living multicostate mosses. [ABSTRACT FROM AUTHOR]

Premise: An anatomically preserved fossil fern sporeling has been discovered in a Lower Cretaceous marine concretion from Vancouver Island, British Columbia, Canada, providing an opportunity to characterize rhizome growth from an extinct species. Methods: The specimen was studied from serial transverse sections prepared by the cellulose acetate peel technique. Results: The rhizome ranges from ~0.7 to 1.1 mm in diameter, has a sclerenchymatous pith, a stele that attains a dictyoxylic architecture, and sclerenchymatous outer cortex, features that are characteristic of osmundaceous rhizomes. Cauline xylem forms a medullated protostele or solenostele at some levels, but is dissected into discrete xylem bundles at others. Fronds diverge in a helical phyllotaxis, range up to 1.1 mm in greatest dimension, and have a C‐shaped trace and outer cortex of sclerotic cells. Inside the sclerenchyma of the petioles are two lateral sclerotic strands and a sclerotic bundle adaxial to the trace. Together, these characters reveal the occurrence of a new species, Todea minutacaulis and provide evidence for developmental changes that occur in the rhizome as the sporeling increased in size. Conclusions: Small size of the specimen, medullated protostelic‐dictyoxylic solenostelar vascular architecture, and incompletely sclerified cells apically reveal that osmundaceous sporeling development has remained constant since at least the Early Cretaceous. Together with Todea tidwellii and Osmunda vancouverensis that also are present in the Apple Bay flora, this sporeling documents the occurrence of a multispecies assemblage of osmundaceous ferns and demonstrates that the genus Todea was diversifying rapidly by the Early Cretaceous. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY:: Diverse in modern ecosystems, mosses are dramatically underrepresented in the fossil record. Furthermore, most pre‐Cenozoic mosses are known only from compression fossils, lacking detailed anatomical information. When preserved, anatomy vastly improves resolution in the systematic placement of fossils. Lower Cretaceous deposits at Apple Bay (Vancouver Island, British Columbia, Canada) contain a diverse anatomically preserved flora that includes numerous bryophytes, many of which have yet to be characterized. Among them is a polytrichaceous moss that is described here. METHODS:: Fossil moss gametophytes preserved in four carbonate concretions were studied in serial sections prepared using the cellulose acetate peel technique. KEY RESULTS:: We describe Meantoinea alophosioides gen. et sp. nov., a polytrichaceous moss with terminal gemma cups containing stalked, lenticular gemmae. Leaves with characteristic costal anatomy, differentiated into sheathing base and free lamina and bearing photosynthetic lamellae, along with a conducting strand in the stem, place Meantoinea in family Polytrichaceae. The bistratose leaf lamina with an adaxial layer of mamillose cells, short photosynthetic lamellae restricted to the costa, and presence of gemma cups indicate affinities with basal members of the Polytrichaceae, such as Lyellia, Bartramiopsis, and Alophosia. CONCLUSIONS:: Meantoinea alophosioides enriches the documented moss diversity of an already‐diverse Early Cretaceous plant fossil assemblage. This is the third moss described from the Apple Bay plant fossil assemblage and represents the first occurrence of gemma cups in a fossil moss. It is also the oldest unequivocal record of Polytrichaceae, providing a hard minimum age for the group of 136 million years. [ABSTRACT FROM AUTHOR]

The evolutionary history of Pinaceae is documented by numerous fossils, which include a number of anatomically preserved ovulate cones with many systematically informative characters. To date, four extinct genera have been recognized:Pseudoaraucaria,Pityostrobus,ObirastrobusandEathiestrobus. A new pinaceous cone from the Early Cretaceous of California is described asPityostrobus pluriresinosasp. nov., adding to the diversity of known Cretaceous pinaceous cones. Phylogenetic analysis places the new fossil cone in the pinoid clade along withPinus,Eathiestrobusand numerous species ofPityostrobus. Combined with a non-metric multidimensional scaling ordination, the data reinforce that whilePityostrobusdoes not represent a natural genus, it likely reflects the rapid evolution of Pinaceae by showing that ovulate cone morphospace was widely occupied byPityostrobusthat has become more restricted in extant genera. Early Cretaceous taxa from Europe and eastern North America show the broadest occupation of morphospace, which then became more restricted to morphologies typical of the pinoid clade in the Late Cretaceous. Taxa from western North America and Asia are more similar to extant genera and occupy a smaller part of the morphospace, highlighting that eastern North America–Europe probably represents an original centre of early diversification for Pinaceae. [ABSTRACT FROM AUTHOR]

Premise of research. Despite an increase in interest in the fossil record of bryophytes (i.e., liverworts, hornworts, and mosses), the biology and taxonomy of these organisms remain understudied and, at times, elusive. In the pre-Cenozoic, especially, few taxonomically informative moss fossils are known. From this perspective, the anatomically preserved Apple Bay flora of Vancouver Island holds a wealth of Cretaceous moss diversity that, until very recently, has remained unexplored. Methodology. Fossils are preserved anatomically in carbonate concretions and studied in serial sections prepared using the cellulose acetate peel technique. Pivotal results. Krassiloviella limbelloides gen. et sp. nov., defined by tricostate homocostate leaves and much-branched stems, is a new addition to the pleurocarpous moss family Tricostaceae (superorder Hypnanae). Conclusions. Krassiloviella limbelloides is the second bryophyte described as a result of ongoing studies of the Early Cretaceous Apple Bay flora of Vancouver Island. Krassiloviella is also the second genus of family Tricostaceae, which provides the oldest unequivocal evidence for the pleurocarpous superorder Hypnanae and a hard minimum age for the group. Revealing aspects of diversity unaccounted for in extant floras, such fossil bryophyte discoveries emphasize the importance of paleontology for efforts aimed at documenting the history of biodiversity. [ABSTRACT FROM AUTHOR]

Premise of research. A large number of floating aquatic aroid fossils have been recovered from pond sediments in the Hell Creek Formation (Upper Cretaceous) of South Dakota, providing valuable new data about aquatic vegetation of the uppermost Cretaceous, that are used to describe a newspecies of the genus Cobbania, and to evaluate associated reproductive structures and phylogenetic relationships among floating aquatic monocots. Methodology. Fossils were uncovered as needed with fine needles to reveal surface features of the specimens. Images were captured with a digital scanning camera, and phylogenetic analyses were conducted with TNT implemented through WinClada. Pivotal results. The new species, Cobbania hickeyi Stockey, Rothwell & Johnson, extends the range of the genus to the uppermost Cretaceous, supports the taxonomic integrity of the genus Cobbania, and increases our understanding of structural variation and species richness within the genus. Associated reproductive structures include an aroid spadix, strengthening the assignment of Cobbania to the Araceae. Phylogenetic analyses using "total-evidence" data help resolve conflicting results from either morphological or nucleotide sequence analyses of relationships among floating aquatic aroids, and the fossil taxon Aquaephyllum does not nest among the other floating aquatic species in any of our results. Conclusions. Species of the genus Cobbania were an important component of aquatic vegetation across the Northern Hemisphere during the Late Cretaceous. In tests of competing hypotheses for relationships among Pistia stratiotes, Cobbania spp., and species of Araceae subfamily Lemnoideae, the results from a "total-evidence" analysis suggest that specializations for the floating aquatic life form may be overwhelming other characters in the results of morphological analyses alone. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: The basal asterid clade Cornales radiated during the Late Cretaceous. However, our understanding of early evolutionary patterns and relationships remain obscure. New data from five permineralized fruits in calcareous concretions from the Upper Cretaceous (Coniacian-Santonian) Haborogawa Formation, Hokkaido, Japan provide anatomical details that aid our knowledge of the group. METHODS: Specimens were studied from cellulose acetate peels, and three-dimensional reconstructions were rendered using AVIZO. KEY RESULTS: Fruits are drupaceous, roughly pyriform, 2.9-4.3 mm in diameter, with a fleshy mesocarp, transition sclereids, and a stony endocarp of four tofive locules, with the septa forming a cross or star-like pattern in transverse section, distinct germination valves, and one apically attached anatropous seed per locule. Vascular tissue occurs in zones between the mesocarp and exocarp, in two rows within the septa, and prominent seed bundles can be traced throughout the fruit sections. Seeds have a single integumentary layer of radially flattened square to rectangular cells and copious cellular endosperm. A fully formed, straight, cellular dicotyledonous embryo, with closely appressed, spathulate cotyledons, is present within each seed. CONCLUSIONS: The unique combination of characters shown by these fruits is found in Cornaceae, Curtisiaceae, and Davidiaceae and allows us to describe a new taxon of Cornales, Eydeia hokkaidoensis gen. et sp. nov., with many similarities to extant Davidia involucrata. These fossils underscore the phylogenetic diversification of Cornales that was underway during the Late Cretaceous and support the hypothesis that a Davidia-like fruit morphology is plesio-morphic within Cornales. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: Discovery of cupulate ovules of Doylea tetrahedrasperma within a compact, compound seed cone highlights the rich diversity of fructification morphologies, pollination biologies, postpollination enclosure of seeds, and systematic diversity of Early Cretaceous gymnosperms. METHODS: Specimens were studied using the cellulose acetate peel technique, three-dimensional reconstructions (in AVIZO), and morphological phylogenetic analyses (in TNT). KEY RESULTS: Doylea tetrahedrasperma has bract/fertile short shoot complexes helically arranged within a compact, compound seed cone. Complexes diverge from the axis as a single unit and separate distally into a free bract tip and two sporophylls. Each sporophyll bears a single, abaxial seed, recurved toward the cone axis, that is enveloped after pollinaton by sporophyll tissue, forming a closed cupule. Ovules are pollinated by bisaccate grains captured by micropylar pollination horns. CONCLUSIONS: The unique combination of characters shown by D. tetrahedrasperma includes the presence of cupulate seeds borne in conifer-like compound seed cones, an ovuliferous scale analogue structurally equivalent to the ovulate stalk of Ginkgo biloba, gymnospermous pollination, and nearly complete enclosure of mature seeds. These features characterize the Doyleales ord. nov., clearly distinguish it from the seed fern order Corystospermales, and allow for recognition of another recently described Early Cretaceous seed plant as a second species in genus Doylea. A morphological phylogenetic analysis highlights systematic relationships of the Doyleales ord. nov. and emphasizes the explosive phylogenetic diversification of gymnosperms that was underway at the time when flowering plants may have originated and/or first began to radiate. [ABSTRACT FROM AUTHOR]

Premise of research. A large pollen cone cluster attached to a cunninghamioid twig and surrounded by leaves has been identified from Eocene calcium carbonate marine concretions from the Appian Way locality on Vancouver Island, British Columbia, Canada. The cluster preserves 18 cones but probably bore at least 24 pollen cones based on cone placement in the cluster. Methodology. Specimens were studied using the cellulose acetate peel technique, and reconstructions were made with ImageJ visualization software. Pollen was examined using SEM. Pivotal results. Cones are helically arranged around the tip of an ultimate leafy branch that terminates in scale leaves, each showing a central resin canal. Vegetative leaves on the twig are amphistomatic, showing typical cunninghamioid anatomy, with a large central resin canal abaxial to the vascular bundle, an elongate zone of transfusion tissue, a nonplicate mesophyll, and a hypodermis three to four cells thick. Each pollen cone is produced in the axil of a bract and has three scale leaves surrounding the base of the cone axis. Individual pollen cones have helically arranged microsporophylls, each with three elongate abaxial pollen sacs. While the cones are immature, pollen sacs with pollen are present in several cones. The exine is scabrate, with numerous orbicules, and no papilla is evident. Conclusions. This cluster provides the first detailed anatomically preserved fossil evidence for the pollen cones of Cunninghamia. It shows a large number of similarities to the pollen cone clusters of extant Cunninghamia lanceolata and Cunninghamia konishii and the Late Cretaceous Cunninghamia taylorii, strengthening hypotheses for a basal position of cunninghamioids within the Cupressaceae and further demonstrating that some characters of Cunninghamia have remained relatively unchanged since at least the mid-Cretaceous. [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 research. Twenty-one permineralized fossil flowers assignable to Lauraceae from the Eocene Appian Way locality on Vancouver Island, British Columbia, Canada, provide important anatomical and morphological data for interpreting evolutionary patterns in this diverse magnoliid family. Methodology. Consecutive anatomical sections were prepared using the cellulose acetate peel technique. Morphology and anatomy of the flowers were determined from anatomical sections, and three-dimensional reconstructions were rendered from serial sections using the software Amira. Pivotal results. Fossil flowers with oil bodies, trichomes, pollen, ovary anatomy, and other characters have allowed for the reconstruction of actinomorphic, pedicellate, and trimerous flowers with tepals in two whorls adnate to a shallow hypanthium. Nine fertile stamens occur in three whorls, the innermost of which bears paired glandular appendages, and a fourth whorl of sagittate staminodes surrounds the carpel. Anthers are tetrasporangiate. Stamens of the two outer whorls have median pollen sacs that are shorter than the two marginal pollen sacs. Third-whorl stamens have median pollen sacs that are longer than the marginal pollen sacs. Anthers of the first and second whorls are introrse, while the third-whorl anthers are extrorse. The fossil flowers have diagnostic characters of Lauraceae and are compared to flowers of extinct and extant taxa. Conclusions. The Eocene floral remains are assigned to Tinaflora beardiae gen. et sp. nov. We infer some aspects of floral biology based on different stages of development preserved among the fossils. The combination of well-preserved floral organs and in situ pollen is rare in the fossil record, allowing T. beardiae to expand the diversity of lauraceous floral morphology and provide further evidence for an Eocene radiation of the family in Laurasia. [ABSTRACT FROM AUTHOR]

Premise of research. A new, morphologically distinct, anatomically preserved conifer assignable to the basal Cupressaceae, which was subject to arthropod infestation during life, has been discovered within a marine carbonate concretion from the Coniacian (Late Cretaceous) Eden Main locality of Vancouver Island, British Columbia. Methods. Specimens were studied from anatomical sections prepared using the classic cellulose acetate peel technique. Pivotal results. This plant, described as Acanthostrobus edenensis gen. et sp. nov., has helically arranged needle leaves and terminal seed cones composed of numerous helically arranged bract/scale complexes dominated by the bract. Both vegetative leaves and bracts display exceptionally long, narrow tips that may have been involved in predator deterrence. The seed cone has diminutive ovuliferous scales with free distal margins; bract/scale complexes bear two to four small, secondarily inverted ovules. Cone tissues contain arthropod feeding galleries surrounded by necrotic tissue and closing tissue (wound periderm) that proliferated throughout the specimen. Conclusions. The new plant is clearly attributable to basal Cupressaceae (Cunninghamioideae, Taiwanioi-deae, and Athrotaxoideae). While it shares features with extinct Jurassic and Cretaceous Cupressaceae, it exhibits a novel combination of characters that distinguishes it from previously described genera. This discovery expands our understanding of basal cupressaceous diversity and provides insight into conifer-animal interactions during the Cretaceous. [ABSTRACT FROM AUTHOR]

Premise: Anatomically preserved evidence for a novel clade of gymnosperms emphasizes diversity of seed plants immediately prior to the appearance of angiosperm fossils in the paleontological record. Methods: Cupulate seeds from the Early Cretaceous Apple Bay locality (Vancouver Island) are described from serial cellulose acetate peels and three‐dimensional reconstruction. Phylogenetic context is assessed through the comparative analysis of gymnosperm seed producing fructifications and maximum parsimony analysis of a revised morphological data set for seed plant phylogeny. Results: Xadzigacalix quatsinoensis gen. et sp. nov. is characterized by an orthotropous ovule with an elongated micropyle and complex integument, enclosed within a radial cupule. The micropylar canal is elongated; and the nucellus extends into the micropyle to seal the post pollination ovule. Except at the apex of the micropyle, the seed is completely enclosed by a parenchymatous cupule with ca. 20 axially elongated secretory ducts. The cupulate seed is produced upon a triangular woody stele, consisting of a parenchymatous pith surrounded by radially aligned tracheids. The stele produces three short terete traces that terminate within the base of the cupule as transfusion tissue at the seed chalaza. Conclusions: Organography, vascularization, nature of the integument and nucellus, and configuration of the micropylar canal distinguish Xadzigacalix quatsinoensis from all other gymnosperm clades. Cladistic analyses suggest the new plant may have affinities with gnetophytes or angiosperms. These results are complemented with a critical re‐evaluation of ovulate structures for Mesozoic gymnosperms, providing new insight into plant diversity immediately antecedent to the explosive diversification of flowering plants. [ABSTRACT FROM AUTHOR]

Conifers of the taxodiaceous grade of Cupressaceae were more diverse and widespread during the Mesozoic than they are today. The earliest diverging subfamily, Cunninghamioideae, only includes a single extant genus, but has at least 10 fossil genera. Here, two additional cunninghamioid genera are characterized on the basis of permineralized seed cones from the Upper Cretaceous of Hokkaido, Japan. These conifers display seed cone characters typical of cunninghamioids; however, they have a mosaic of characters that are not seen in any reported conifer of Cupressaceae. They are, therefore, designated as two new extinct species: Ohanastrobus hokkaidoensis gen. et sp. nov. and Nishidastrobus japonicum gen. et sp. nov. These newly reported conifers expand the taxonomic and morphological diversity of cunninghamioids. The stratigraphic and paleobiogeographic records of cunninghamioids and other fossil Cupressaceae with foliate seed cones indicate they peak in diversity during the Cretaceous. The living genera Taiwania and Cunninghamia appear during the Albian and Campanian, respectively, and maintain a nearly continuous fossil record through to today, while nearly all other extinct genera of Cupressaceae with foliate cones disappear by the close of the Campanian. As more ancient cunninghamioids are recovered, our understanding of macroevolutionary patterns of this once diverse lineage will be further elucidated. [ABSTRACT FROM AUTHOR]

PREMISE: Mosses are a major component of Arctic vegetation today, with >500 species known to date. However, the origins of the Arctic moss flora are poorly documented in the fossil record, especially prior to the Pliocene. Here, we present the first anatomically preserved pre‐Cenozoic Arctic moss and discuss how the unique biology of bryophytes has facilitated their success in polar environments over geologic time. METHODS: A permineralized fossil moss gametophyte within a block of Late Cretaceous terrestrial limestone, collected along the Colville River on the North Slope of Alaska, was studied in serial sections prepared using the cellulose acetate peel technique. RESULTS: The moss gametophyte is branched and has leaves with a broad base, narrow blade, and excurrent costa. We describe this fossil as Cynodontium luthii sp. nov., an extinct species of a genus that is known from the High Arctic today. Cynodontium luthii is the oldest evidence of the family Rhabdoweisiaceae (by ≥18 Ma) and reveals that genera of haplolepideous mosses known in the extant Arctic flora also lived in high‐latitude temperate deciduous forests during the Late Cretaceous. CONCLUSIONS: The occurrence of C. luthii in Cretaceous sediments, together with a rich Pliocene‐to‐Holocene fossil record of extant moss genera in the High Arctic, suggests that some moss lineages have exploited their poikilohydric, cold‐ and desiccation‐tolerant physiology to live in the region when it experienced both temperate and freezing climates. [ABSTRACT FROM AUTHOR]

Premise of the Study: Recent clarification of the distribution of Marattiales through time provides the impetus for “total evidence” phylogenetic analyses of a major fern clade with a rich fossil record. These analyses serve as empirical tests for results from systematic analyses of living species and also of the belief that relationships among living species accurately reflect the overall pattern of phylogeny for clades with an extensive fossil record and a large percentage of extinction. Methods: Species of living and fossil Marattiaceae are analyzed employing a “total evidence approach” via maximum parsimony. Analyses were conducted using TNT implemented through WinClada. Key Results: Systematic analyses of living species and of living + extinct species provide roughly concordant topologies for living taxa. However, living species of Marattiales are only one component of a much larger clade with two major subclades. One consists of Psaroniaceae and extends through time to at least the Early Cretaceous. The other consists of Marattiaceae and includes all living species. Various analyses support the generic‐level clades of living species from earlier analyses, but the arrangement of such clades varies from analysis to analysis. Conclusions: Marattiales is a monophyletic group that is extremely common in late Paleozoic and early Mesozoic deposits, with a stem group Psaroniaceae and a crown group Marattiaceae. Because Marattiaceae represents only a small component of overall marattialean diversity, living species alone neither account for evolutionary changes within the clade over time, nor accurately reflect the overall pattern of marattialean fern phylogeny. [ABSTRACT FROM AUTHOR]

• Background and Aims Widespread and diverse in modern ecosystems, mosses are rare in the fossil record, especially in pre-Cenozoic rocks. Furthermore, most pre-Cenozoic mosses are known from compression fossils, which lack detailed anatomical information. When preserved, anatomy significantly improves resolution in the systematic placement of fossils. Lower Cretaceous (Valanginian) deposits on Vancouver Island (British Columbia, Canada) contain a diverse anatomically preserved flora including numerous bryophytes, many of which have yet to be characterized. Among them is the grimmiaceous moss described here. • Methods One fossil moss gametophyte preserved in a carbonate concretion was studied in serial sections prepared using the cellulose acetate peel technique. • Key Results Tricarinella crassiphylla gen. et sp. nov. is a moss with tristichous phyllotaxis and strongly keeled leaves. The combination of an acrocarpous condition (inferred based on a series of morphological features), a central conducting strand, a homogeneous leaf costa and a lamina with bistratose portions and sinuous cells, and multicellular gemmae, supports placement of Tricarinella in family Grimmiaceae. Tricarinella is similar to Grimmia, a genus that exhibits broad morphological variability. However, tristichous phyllotaxis and especially the lamina, bistratose at the base but not in distal portions of the leaf, set Tricarinella apart as a distinct genus. • Conclusions Tricarinella crassiphylla marks the oldest record for both family Grimmiaceae and sub-class Dicranidae, providing a hard minimum age (136 million years) for these groups. The fact that this fossil could be placed in an extant family, despite a diminutive size, emphasizes the considerable resolving power of anatomically preserved bryophyte fossils, even when recovered from allochthonous assemblages of marine sediments, such as the Apple Bay flora. Discovery of Tricarinella re-emphasizes the importance of paleobotanical studies as the only approach allowing access to a significant segment of biodiversity, the extinct biodiversity, which is unattainable by other means of investigation. [ABSTRACT FROM AUTHOR]

Premise of research. A distinctive new species of osmundaceous fern, based on a permineralized trunk from Lower Cretaceous deposits of Haida Gwaii (formerly the Queen Charlotte Islands) off the west coast of mainland Canada, provides additional data for addressing the Mesozoic diversity and the overall pattern of phy-logeny for osmundaceous filicalean ferns. Methodology. The specimen was cut into segments and studied from both external morphology and anatomical sections prepared by the cellulose acetate peel technique. Microscope slides of sections were examined, and images were captured under transmitted light. Pivotal results. The fossil represents a new species of Osmundacaulis, which is only the third Northern Hemisphere representative of this predominantly Southern Hemisphere genus. Conclusions. Osmundacaulis whittlesii sp. nov. increases the Northern Hemisphere diversity of Cretaceous Osmundaceae, thus providing new data about Mesozoic diversity of the clade, potential sister-group relationships of crown-group Osmundaceae, and the overall pattern of phylogeny for Osmundaceae. [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]

Premise of research. Anatomically preserved platanaceous inflorescences have been found in rocks of Late Cretaceous (Coniacian) age at the Eden Main locality on Vancouver Island, British Columbia, Canada. Methodology. Specimens occur in calcium carbonate concretions near the base of the Nanaimo Group (Comox Formation) and are studied with the cellulose acetate peel technique and SEM. Pivotal results. Inflorescences are small (<5 mm), pedunculate heads, with fewer than 30 ?flowers per inflorescence. Both bisexual and unisexual flowers are present on the same inflorescence. Elongate and overarching tepals enclose the developing gynoecium and androecium at early stages of development. More mature specimens have individual flowers with at least two whorls of tepals fused toward the base. Flowers have a whorl of five free stamens, each with short filaments and a sclerotic apical connective extension. In situ pollen is small, prolate, tricolpate, 11-13 μm in polar diameter, and 8-9 μm in equatorial diameter. In flowers where it can be observed, the staminal whorl encloses five short, conduplicate, glabrous carpels lacking differentiated styles but bearing broad, flat apices. The ovary of these carpels is occupied by a single ovule. Conclusions. While the Eden Main specimens display a five-parted gynoecial arrangement common in the pistillate flowers of other Cretaceous platanoids, Ambiplatanus washingtonensis gen. et sp. nov. provides the first fossil evidence of functional bisexuality in fossil Platanaceae. [ABSTRACT FROM AUTHOR]

Premise: Fossils show that fly‐speck fungi have been reproducing with small, black thyriothecia on leaf surfaces for ~250 million years. We analyzed morphological characters of extant thyriothecial fungi to develop a phylogenetic framework for interpreting fossil taxa. Methods: We placed 59 extant fly‐speck fungi in a phylogeny of 320 Ascomycota using nuclear ribosomal large and small subunit sequences, including newly determined sequences from nine taxa. We reconstructed ancestral character states using BayesTraits and maximum likelihood after coding 11 morphological characters based on original observations and literature. We analyzed the relationships of three previously published Mesozoic fossils using parsimony and our morphological character matrix, constrained by the molecular phylogeny. Results: Thyriothecia evolved convergently in multiple lineages of superficial, leaf‐inhabiting ascomycetes. The radiate and ostiolate scutellum organization is restricted to Dothideomycetes. Scutellum initiation by intercalary septation of a single hypha characterizes Asterinales and Asterotexiales, and initiation by coordinated growth of two or more adjacent hyphae characterizes Aulographaceae. Scutella in Microthyriales are initiated apically on a lateral hyphal branch. Patterns of hyphal branching in scutella contribute to distinguishing among orders. Parsimony resolves three fossil taxa as Dothideomycetes; one is further resolved as a member of a Microthyriales‐Zeloasperisporiales clade within Dothideomycetes. Conclusions: This is the most comprehensive systematic study of thyriothecial fungi and their relatives to date. Parsimony analysis of the matrix of character states of modern taxa provides an objective basis for interpreting fossils, leading to insights into morphological evolution and geological ages of Dothideomycetes clades. [ABSTRACT FROM AUTHOR]

Relationships of living and fossil Pinaceae were inferred using parsimony and Bayesian inference of morphological characters and plastid and nuclear DNA sequences. When considering extant taxa only, adding molecular to morphological characters resulted in markedly increased resolution and branch support compared with analysis of morphology alone. Including 45 fossil taxa resulted in drastically decreased resolution in morphology-based consensus trees. We evaluated the effect on branch support and resolution of including DNA sequences, deleting fossils lacking information for cone scale apices and seeds, using reduced consensus methods, and using implied weighting, and found that the greatest improvements were found by including DNA sequences and using implied weighting. The tree topologies from parsimony and Bayesian inference confirm previous findings that the fossil genus Pseudoaraucaria and a few species of Pityostrobus from the Lower Cretaceous are related to abietoid genera, and that other species of Pityostrobus are pinoid and closely related to Pinus. Focusing phylogenetic analyses on the most complete fossil cones, specifically those that are anatomically preserved and include both cone scale apices and seeds, and taking into account homoplasy, resulted in the clearest hypotheses for the timing and sequence of diversification in the family. [ABSTRACT FROM AUTHOR]

Premise of research. Humiriaceae occupy predominantly Neotropical lowland rainforests, with only a single Old World species in western Africa. Molecular divergence time estimates suggest that the family might have originated during the middle Cretaceous; however, fossil occurrences are lacking prior to the Paleocene. Here we provide new fossil evidence that expands our understanding of the paleobiogeographic history and evolution of this family. Methodology. Fossil endocarps and wood were compared with extant relatives of the family. Transverse and longitudinal sections of fossil and modern fruits were studied anatomically and morphologically. Pivotal results. Fruits of the new species, Duckesia berryi sp. n., from the Oligocene of Pacific coastal Peru (ca. 30-28.5 Ma), provide the earliest fossil evidence of Duckesia--the genus is now confined to Amazonia. We also document the earliest fossil fruit record for Sacoglottis tertiaria, from the early Oligocene (ca. 33.9-28.4 Ma) of Puerto Rico, and a new occurrence of Vantanea cipaconensis fruits, from the late Miocene of Panama (ca. 9-8.5 Ma). The new fossil wood, Humiriaceoxylon ocuensis gen. et. sp. n., from the late Eocene (ca. 37.2-33.9 Ma) of Ocú, Panama, confirms that this family was represented by large trees anatomically consistent with the extant genera. Conclusions. Humiriaceae originated in the Neotropics, with the oldest-known occurrences being fruits of Lacunofructus cuatrecasana and wood of H. ocuensis from the late Eocene of Panama. The family was generically diverse and widely distributed geographically across northern South America and Central America by the early Miocene. The new fossils also provide further evidence of regional extinctions within the Neotropics; extirpation of particular genera from Central America, the Caribbean, and coastal Peru indicate that Neogene orogenic and climatic events had an important effect on the modern-day distribution of the family. [ABSTRACT FROM AUTHOR]