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. 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]

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]

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. 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. 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 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]

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: 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]

More than 800 permineralized fagaceous fruits have been studied from the Eocene Appian Way locality of Vancouver Island, British Columbia. These cupulate nuts are the most common fruits preserved at the locality. They occur in calcareous concretions and were studied using the cellulose acetate peel technique. Cupules are borne on a spiny stalk and are broadly ovate in both longitudinal and transverse section. Cupules are evalvate and have both branching and simple spines. A single, ovoid, sclerotic nut is enclosed entirely by the cupule, except at the apex, where a stylar protrusion is free from any surrounding tissues. The nut is bilocular with a glabrous endocarp lining. At maturity, a single seed occupies the locular cavity. The embryo is straight and no endosperm is evident. The single-fruited, spiny cupule is most similar to fruits of Fagaceae subfamily Castaneoideae. Bicarpellate fruits and a glabrous endocarp place them within the fossil genus Cascadiacarpa; however, they differ from Cascadiacarpa spinosa in nut wall anatomy, cupule ornamentation, shape, and size. Fruits of Cascadiacarpa exilis sp. nov. are compared with spiny, small compression and impression fossil fruits from the Eocene Taneum Creek locality of Washington State. The characters of the Washington State fossils overlap with those observed in the anatomically preserved Appian Way cupulate fruits and, as such, may represent compression and impression fossils of the same genus. The permineralized fruits document that evalvate, spiny, cupulate nuts of Fagaceae were present and common in the Eocene of western North America. [ABSTRACT FROM AUTHOR]

Premise of the study: Colonists of even the most inhospitable environments, lichens are present in all terrestrial ecosystems. Because of their ecological versatility and ubiquity, they have been considered excellent candidates for early colonizers of terrestrial environments. Despite such predictions, good preservation potential, and the extant diversity of lichenized fungi, the fossil record of lichen associations is sparse. Unequivocal lichen fossils are rare due, in part, to difficulties in ascertaining the presence of both symbionts and in characterizing their interactions. This study describes an exceptionally well-preserved heteromerous lichen from the Lower Cretaceous of Vancouver Island. Methods: The fossil occurs in a marine carbonate concretion collected from the Apple Bay locality on Vancouver Island, British Columbia, and was prepared for light microscopy and SEM using the cellulose acetate peel technique. Key results: The lichen, Honeggeriella complexa gen. et sp. nov., is formed by an ascomycete mycobiont and a chlorophyte photobiont, and exhibits heteromerous thallus organization. This is paired with a mycobiont-photobiont interface characterized by intracellular haustoria, previously not documented in the fossil record. Conclusions: Honeggeriella adds a lichen component to one of the richest and best characterized Early Cretaceous floras and provides a significant addition to the sparse fossil record of lichens. As a heteromerous chlorolichen, it bridges the >350 million-year gap between previously documented Early Devonian and Eocene occurrences. [ABSTRACT FROM AUTHOR]

• Premise of the study: Morphology is a reflection of evolution, and as the majority of biodiversity that has lived on Earth is now extinct, the study of the fossil record provides a more complete picture of evolution. This study investigates anatomically preserved bryophyte fossils from the Eocene Oyster Bay Formation of Vancouver Island. While the bryophyte fossil record is limited in general, anatomically preserved bryophytes are even more infrequent; thus, the Oyster Bay bryophytes are a particularly significant addition to the bryophyte fossil record. • Methods: Fossils occur in two marine carbonate nodules collected from the Appian Way locality on the eastern shore of Vancouver Island, British Columbia, and were prepared using the cellulose acetate peel technique. • Key results: The fossils exhibit a novel combination of characters unknown among extinct and extant liverworts: (1) three-ranked helical phyllotaxis with underleaves larger than the lateral leaves; (2) fascicled rhizoids associated with the leaves of all three ranks; (3) Anomoclada-type endogenous branching. • Conclusions: A new liverwort family, Appianacae fam. nov., is established based upon the novel combination of characters. Appiana gen. nov. broadens the known diversity of bryophytes and adds a hepatic component to one of the richest and best characterized Eocene floras. [ABSTRACT FROM AUTHOR]

The Eocene Princeton Chert locality of southern British Columbia, Canada, provides data to develop organismal concepts for several species of fossil plants, including the first extinct species of Pinaceae, Pinus arnoldii Miller . This new species concept is based on a combination of interconnected organs, common histological features, and patterns of association among isolated plant parts. These data expand our knowledge of P. arnoldii from a morphospecies of ovulate cones to an extinct species of pine that produces woody stems with five-needled fascicles of leaves; simple pollen cones with two abaxial pollen sacs per microsporophyll, containing bisaccate pollen grains; seed cones with inflated scale apices, dorsal umbos that do not bear mucros, and a thick-walled sclerotic outer cortex; and coralloid roots with ectomycorrhizal associations. Organs preserved at various stages of development provide evidence for numerous aspects of growth and reproductive biology, including pollination biology and seed cone development. Cladistic analyses of morphological and molecular characters demonstrate that the novel combination of characters displayed by P. arnoldii causes this extinct species to fall near the base of the Pinus L. tree, either as the sister to all living species of the subgenus Pinus or outside the subgenera that have been defined by extant species of Pinus. [ABSTRACT FROM AUTHOR]

A new species of extinct conifer plants, Emporia royalii sp. nov. Hernandez-Castillo, Stockey, Mapes et Rothwell (Emporiaceae: Voltziales), is described from the rich fossil biota of the Late Pennsylvanian, Hamilton Quarry, Kansas. This conifer has lateral plagiotropic branches with simple and forked leaves, "age-dependent heterophylly," simple pollen cones, and compound ovulate cones. Stems have an endarch eustele, dense wood, and secretory cells arranged in nests or plates in the pith. Leaves are amphistomatic with two adaxial stomatal bands and two longitudinal abaxial rows of stomata with numerous trichome bases. Pollen cones are simple and have helically arranged microsporophylls with adaxial pollen sacs. Prepollen is monolete and monosaccate (Potonieisporites Bharadwaj). Ovulate cones are compound with bilaterally symmetrical axillary dwarf shoots that bear up to 45 sterile scales and 1-2 sporophylls and occur in the axils of helically arranged bracts with forked tips. Ovules are inverted and winged and resemble those of Emporia lockardii and Emporia cryptica. Emporia royalii is compared to other Euramerican waichian Voltziales, and a summary of the Emporiaceae and evolution of Paleozoic conifers is given. This is the fifth species of extinct conifer plants to be reconstructed from the Hamilton Quarry, making it the only Paleozoic locality in the world with numerous conifers all of which have been characterized as complete or nearly complete plants. [ABSTRACT FROM AUTHOR]

Abstract: This paper provides a whole plant concept for a new species, Emporia cryptica sp. nov. Hernandez-Castillo, Stockey, Rothwell & Mapes (Emporiaceae: Voltziales), the fourth conifer to be reconstructed from the rich fossil biota at the Late Pennsylvanian, Hamilton Quarry, Kansas. E. cryptica has an orthotropic stem, lateral plagiotropic branches with simple leaves, simple pollen cones, and compound ovulate cones. Branches have an endarch eustele with dense wood surrounding a parenchymatous pith with sclerotic nests/plates, and secondary xylem tracheids with multiseriate hexagonal bordered pits. Leaves on both penultimate and ultimate branches are simple and amphistomatic with two adaxial stomatal bands, monocyclic and dicyclic stomata, and two narrow abaxial rows of stomata with numerous trichome bases. Pollen cones are simple with helically arranged microsporophylls and adaxial pollen sacs. Prepollen is monolete, eusaccate, and monosaccate (Potonieisporites Bharadwaj). Ovulate cones are compound with bilaterally symmetrical dwarf shoots in the axils of helically arranged forked bracts. Axillary dwarf shoots bear numerous sterile scales interspersed with two megasporophylls, each bearing a single inverted terminal ovule. This plant displays morphological and cuticular characters similar to several morphogenera of Paleozoic walchian conifers but is most comparable to the fossil plant species Emporia lockardii and Hanskerpia hamiltonensis. E. cryptica is the only walchian conifer where ovules and seeds with megagametophytes, immature embryos and mature embryos have been documented, demonstrating that the most ancient conifers possessed seed dormancy and polycotyledonary embryos. This reproductive biology is similar to that of many Mesozoic and extant conifers with saccate pollen except for the presence of prepollen grains that are common among Paleozoic walchian conifers. [Copyright &y& Elsevier]

A diverse assemblage of fossil conifer leaves was identified in calcareous marine concretions from the Lower Cretaceous (Valanginian–Hauterivian) Apple Bay locality, Vancouver Island. Of the hundreds of isolated leaf fragments, most show affinities to Pinaceae. Leaves with closest similarities to Picea (spruce) were studied using cellulose acetate peels. Picea-like leaves vary in cross-section from rhomboidal, pentagonal, triangular, to ovoid. One fused vascular bundle with a centrally located ray and abaxial sclerenchyma is surrounded by a circular endodermis and transfusion tissue. Mesophyll is plicate containing two lateral external resin canals surrounded by a sclerenchyma sheath. Hypodermal fibres are one to three layers thick, except in areas of stomata. Leaves are amphistomatic, with sunken guard cells. Vascular bundles are identical anatomically to Picea; however, plicate mesophyll is similar to that in leaves of Pinus. Extensive sclerenchyma in the hypodermis and surrounding resin canals differs from that in most extant Picea. The major difference between these leaves and those of Picea is leaf shape. These fossil leaves probably belong to an extinct pinaceous conifer, and are described as Midoriphyllum piceoides gen. et sp. nov. Similar evidence from Cretaceous seed cones suggests that like the angiosperms, the Pinaceae were undergoing rapid mosaic evolution during the Lower Cretaceous. [ABSTRACT FROM AUTHOR]

An apparently exindusiate filicalean fern with radial sori, sporangia with a vertical annulus, and monolete spores occurs in Paleocene sediments ca. 57 million years old of central Alberta, Canada. Specimens are preserved as coalified compressions and show features of frond morphology and venation, sporangium morphology and dehiscence mechanism, number of spores per sporangium, and spore fine structure. Fronds have a deltoid blade region and are pinnate + pinnatifid, with fertile pinnules ranging to slightly smaller than vegetative pinnules and with simpler venation. Venation is open, with each lobe of the pinnatifid pinnule having a midvein from which laterals diverge in an alternate pattern. Laterals of vegetative pinnule lobes fork once and terminate at the margin, whereas those of fertile pinnule lobes are unbranched. Sori are round with numerous sporangia and are positioned under a vein. Each sporangium has a vertical annulus that is not interrupted by the stalk and produces ca. 64 spores. Spores are bean shaped and monolete, measuring 26-36 μm long, with exospore that is dense and sculptured by minute scabrae. Perispore is not preserved. This fern, named Speirseopteris orbiculata gen. et sp. nov., displays characters that are diagnostic of the highly derived filicalean families and is assigned to the Thelypteridaceae. To a lesser extent, it also resembles the Dryopteridaceae, emphasizing that modern fern genera existed among many extinct genera during the late Cretaceous and Paleogene. [ABSTRACT FROM AUTHOR]

The discovery of two anatomically preserved rhizomes with attached stipe bases and adventitious roots contributes to our knowledge of filicalean fern diversity and evolution. Specimens are preserved in marine carbonate nodules at the Lower Cretaceous (Valanginian to Hauterivian) Apple Bay locality on Vancouver Island, British Columbia, Canada. They represent a previously unknown filicalean fern with transitional solenostelic-dictyostelic stelar architecture and are described as Stramineopteris aureopilosus gen. et sp. nov. Rhizomes range from 2.5 to 5.5 mm in diameter and are amphiphloic. Arc-shaped leaf traces display a slightly asymmetrical divergence pattern and radiate from all sides of the stele. Primary xylem maturation is exarch. Multicellular trichomes are present throughout but are produced in greater numbers at rhizome dichotomies. Both pith and cortex are of a distinctive heterogeneous construction. A comparison of this distinctive combination of characters to previously described fern rhizomes reveals that vegetative anatomy may be more taxonomically diagnostic for a broader range of ferns than is commonly thought. This realization provides the impetus to explore more closely the distribution of several anatomic characters among leptosporangiate ferns and to reexamine the value of vegetative anatomy for developing a clearer understanding of fern systematics. [ABSTRACT FROM AUTHOR]

Anatomically preserved schizaeaceous vegetative and fertile organs have been identified from the Apple Bay locality (Lower Cretaceous) of Vancouver Island, British Columbia. Specimens are permineralized in calcareous nodules that contain numerous plants and marine invertebrates. Fertile pinnules are pinnately lobed, with abaxial sporangia and abaxially reflexed laminae. The pyriform sporangia have an apical annulus and occur in two rows on each pinnule lobe. Laminar tissue has wavy, thick-walled, adaxial epidermal cells. Spores are tetrahedral to globose with three sets of obliquely arranged parallel muri and correspond to the sporae dispersae genus Cicatricosisporites Potonié et Gelletich. This fertile material most closely resembles Anemia subgenus Anemiorrhiza (Schizaeaceae) and is described as a new species, Anemia quatsinoensis Hernandez-Castillo, Stockey et Rothwell. Fertile pinnae are associated with an exarch, amphiphloic, solenostelic Anemia-like rhizome, with a C-shaped frond trace. Anatomies of the solenostele and frond trace, as well as frond divergence, compare most closely with species of Anemia subgenus Anemiorrhiza and may represent the vegetative shoot of Anemia quatsinoensis. This is the oldest and most complete permineralized fertile material of the genus Anemia in North America, and its presence at Apple Bay is consistent with the hypothesis that much of the diversification of Schizaeaceae had already occurred by the beginning of the 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]

• 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 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]

Premise of research. A third genus of anatomically preserved conifer seed cones has been recognized from a Late Jurassic deposit in northeastern Scotland. This cone is described as Bancroftiastrobus digitata Rothwell, Mapes, Stockey et Hilton. Methodology. The cone was sectioned with the classic coal ball peel technique and studied and photographed with transmission light. Pivotal results. Bancroftiastrobus digitata is a cylindrical cone with large, helically arranged ovuliferous scales subtended by short bracts, each bract/scale complex bearing two unwinged inverted seeds on the adaxial surface of the ovuliferous scale. Ovuliferous scales have abaxial plications in the midregion and divide distally, forming up to nine free distal lobes that are vascularized and covered by a dense ramentum of trichomes. The cone axis forms a continuous woody cylinder that surrounds a parenchymatous pith. There are numerous resin canals in the cortex of the cone axis that extend into each bract/scale complex, both abaxial and adaxial to the vascular traces. Vascular tissue to the bract diverges as a prominent terete bundle that separates from the stele immediately below a large inverted-U-shaped scale trace. More distally, the scale trace flattens and divides into a single row of C-shaped woody bundles. Conclusions. This new genus provides additional evidence for the diversity of stem group conifers that lived during the interval when most crown group conifer families originated. The new species is reminiscent of both Sciadopityaceae and Pinaceae. However, like the three anatomically preserved species of Pararaucaria Wieland (Cheirolepidiaceae), this cone does not clearly conform to any family with living species. Rather, these taxa have novel combinations of characters that make fossils vital for resolving deep internal nodes of the seed plant tree and that help to resolve the overall pattern of phylogeny. [ABSTRACT FROM AUTHOR]

This study describes a specimen that extends the oldest fossil evidence of Pinus L. to the Early Cretaceous Wealden Formation of Yorkshire, UK (131--129 million years ago), and prompts a critical reevaluation of criteria that are employed to identify crown group genera of Pinaceae from anatomically preserved seed cones. The specimen, described as Pinus yorkshirensis sp. nov., is conical, 5 cm long, and 3.1 cm in maximum diameter. Bract/scale complexes are helically arranged and spreading. Vasculature of the axis forms a complete cylinder with few resin canals in the wood, and the inner cortex is dominated by large resin canals. Bracts are short, with two resin canals, and separate from the scale base laterally. Distally, the ovuliferous scales broaden and thicken to form a rhomboidal apophysis with a dorsal umbo, characters found only in the genus Pinus among living conifers. Resin canals enter the ovuliferous scale abaxial to the vascular tissue, which divides distally to form a row of adaxially convex bundles. A short interseminal ridge separates two inverted and winged seeds on the adaxial surface of the ovuliferous scale. Seeds contain megagametophyte tissue and polycotyledonary embryos. Numerical cladistic analysis of anatomically preserved seed cones yields a wellresolved phylogeny of crown and stem group Pinaceae that is roughly concordant with the results of analyses that include living species only. All of the included species of Pinus form a clade with three very Pinus-like species that currently are assigned to the stem genus Pityostrobus. These results call to question the utility of traditional methods for assigning fossil seed cones to Pinus, resolve relationships among stem and crown group genera, and highlight the unnatural circumscription of Pityostrobus. This suggests that some species of Pityostrobus may actually represent the genus Pinus, and it demonstrates that the evolutionary diversification of Pinaceae began earlier than previously recognized from fossil evidence. [ABSTRACT FROM AUTHOR]

This study describes a specimen that extends the oldest fossil evidence of Pinus L. to the Early Cretaceous Wealden Formation of Yorkshire, UK (131-129 million years ago), and prompts a critical reevaluation of criteria that are employed to identify crown group genera of Pinaceae from anatomically preserved seed cones. The specimen, described as Pinus yorkshirensis sp. nov., is conical, 5 cm long, and 3.1 cm in maximum diameter. Bract/scale complexes are helically arranged and spreading. Vasculature of the axis forms a complete cylinder with few resin canals in the wood, and the inner cortex is dominated by large resin canals. Bracts are short, with two resin canals, and separate from the scale base laterally. Distally, the ovuliferous scales broaden and thicken to form a rhomboidal apophysis with a dorsal umbo, characters found only in the genus Pinus among living conifers. Resin canals enter the ovuliferous scale abaxial to the vascular tissue, which divides distally to form a row of adaxially convex bundles. A short interseminal ridge separates two inverted and winged seeds on the adaxial surface of the ovuliferous scale. Seeds contain megagametophyte tissue and polycotyledonary embryos. Numerical cladistic analysis of anatomically preserved seed cones yields a wellresolved phylogeny of crown and stem group Pinaceae that is roughly concordant with the results of analyses that include living species only. All of the included species of Pinus form a clade with three very Pinus-like species that currently are assigned to the stem genus Pityostrobus. These results call to question the utility of traditional methods for assigning fossil seed cones to Pinus, resolve relationships among stem and crown group genera, and highlight the unnatural circumscription of Pityostrobus. This suggests that some species of Pityostrobus may actually represent the genus Pinus, and it demonstrates that the evolutionary diversification of Pinaceae began earlier than previously recognized from fossil evidence. [ABSTRACT FROM AUTHOR]

* Premise of the study: Pinaceae and nonpinoid species are sister groups within the conifer clade as inferred from molecular systematic comparisons of living species and therefore should have comparable geological ages. However, the fossil record for the nonpinoid lineage of extant conifer families is Triassic, nearly 100 million years older than the oldest widely accepted Lower Cretaceous record for Pinaceae. An anatomically preserved fossil conifer seed cone described here extends the stratigraphic range of Pinaceae nearly 30 million years, thus reducing the apparent discrepancy between evidence from the fossil record and inferences from systematic studies of living species. * Methods: Material was prepared as serial thin sections by the cellulose acetate peel technique, mounted on microscope slides, and viewed and photographed using transmitted light. * Key results: A large cylindrical cone consisting of bract-scale complexes that diverge from the cone axis in a helical phyllotaxis has bracts and scales that separate from each other in the midregion and are of equal length and of nearly equal width. The cone has two inverted and winged seeds that are attached to the adaxial surface of each cone scale and, thus, represents an early member of the Pinaceae. * Conclusions: Eathiestrobus mackenziei gen. et sp. nov. extends the fossil record for well-documented members of the family Pinaceae from the Lower Cretaceous to the Kimmeridgian Stage of the Upper Jurassic. This species also clarifies the set of characters that are diagnostic for seed cones of Pinaceae and reveals possible plesiomorphic characters for seed cones of the family. [ABSTRACT FROM AUTHOR]

Three types of anatomically preserved vegetative shoots with features that characterize crown group Equisetwn have been discovered in Lower Cretaceous deposits (≈136 Ma) of British Columbia. Canada, suggesting the genus is much older than currently believed. Specimens include two types of aerial shoots described as E. haukeanum sp. nov. and E. vancouverense sp. nov. and one type of subterranean rhizome. Shoots are 1-2 mm in diameter, jointed, and in cross section have fluted stems with a hollow pith. Distinctive patterns of cortical sclerenchyma and different ridge morphologies characterize each shoot morphotype. Nodes display irregular branching, highly fused leaf sheaths, and a nodal diaphragm. The aerial stem morphospecies have vallecular canals on alternating radii with carinal canals of an equisetostele surrounded by only a few tracheids. No secondary tissues are produced. Bands of surficial stomata flank the furrows of one morphospecies. Rhizomes and aerial shoots are of a similar size, suggesting that the plants were equivalent in stature to the smallest living Equisetuin species. These fossils augment our understanding of evolutionary transformations that led from Paleozoic Archaeocalamitaceae and Calamitaceae to crown group Equisetaceae, suggesting that the initial diversification of Equisetum began far earlier than suggested by molecular-clock-based estimates. [ABSTRACT FROM AUTHOR]

A new genus and species of anatomically preserved fossil filicalean ferns Dickwhitea allenbyensis gen. et sp. nov. is described from the Middle Eocene Princeton Chert of southern British Columbia, Canada. Rhizomes have a parenchymatous pith surrounded by a ring of five amphiphloic cauline bundles and pairs of frond traces that diverge from adjacent cauline bundles in a 2/5 phyllotaxis. The cortex is also parenchymatous except at the periphery, where there is a well-developed sclerotic hypodermis. The stipe is characterized by a pair of hippocampiform bundles, and ground tissues are similar to those of the rhizome. Prominent nests of large cells with black contents occur adjacent to the vascular bundles in the ground tissue of the rhizome and stipe. Roots are diarch with cortex that grades from parenchymatous at the interior to sclerotic at the periphery. The vascular architecture of this fern appears to be novel among known Filicales. There are no gaps in the stele that result from the divergence of either frond or root traces, and there is no evidence that cauline bundles anastomose. Rather, the cauline bundles extend through the rhizome independently of each other, with each cauline bundle producing successive frond traces on alternating tangents. Root traces diverge from the outer surface of cauline bundles as is characteristic of solenostelic filicalean species and dictyostelic tree ferns. Examination of the literature reveals that there is a wide range of variation in filicalean vascular architectures that traditionally has not been recognized. Although there is anecdotal evidence that this newly recognized stelar variation is correlated with patterns of systematic diversity, the overall phylogenetic significance of fern vascular architecture has yet to be fully explored. [ABSTRACT FROM AUTHOR]

Large numbers of permineralized juglandaceous fruits were identified in calcareous nodules from the Eocene Appian Way locality on Vancouver Island, British Columbia, Canada. The fruits, small dorsiventrally flattened nutlets, 4.5–7.0 mm long and 5.5–9.0 × 3–5 mm in diameter, were studied using cellulose acetate peels. They are wingless, ribbed, and have a lobed epicarp that surrounds the hurler. Cells of the inner epicarp are thin-walled and traversed by a system of branching vascular strands. The stony nutlet wall is composed of fibers, with an outer layer of distinctive idioblasts. The fruits have a symmetry like that in Juglandaceae, subfamily Juglandoideae, tribe Platycaryeae, while the fibrous taut walls are like those of subfamily Engelhardioideae. This unique combination of characters indicates that these fruits represent a new genus and species of Juglandaceae: Beardia vancouverensis gen. et sp. nov. The excellent preservation of the Appian Way specimens has allowed a unique view of the internal fruit anatomy and external morphology. As the only wingless, flattened nuts known in the family, they further extend the range of morphological variation in fruits in the family. These fossils further support the hypothesis that North America was an important center of generic diversity for Juglandaceae during the early Tertiary. [ABSTRACT FROM AUTHOR]

A large number of vegetative and fertile branching systems of Thucydia mahoningensis provide data for interpreting the growth architecture and life-history pattern of a primitive Paleozoic conifer. Internal anatomy is similar to modern conifers, indicating an arborescent life-history pattern. Three categories of vegetative plagiotropic branching systems are recognized, and these resemble developmental variations among lateral branching systems in juvenile trees of the extant conifer Araucaria heterophylla (Salisb.) Franco. Thucydia mahoningensis is considered to be a small tree on the basis of the size and branching pattern of the stem and lateral branching systems and on the basis of internal anatomy. Growth architecture of T. mahoningensis conforms to Massart's model, but fertile remains reveal interesting differences from living species. The T. mahoningensis tree has an orthotropic stem that bears two orders of plagiotropic vegetative shoots. Fertile shoots have a compound ovulate fertile zone and lack vegetative lateral branches. Ovulate branches bear penultimate-type vegetative leaves in the basal region, a compound ovulate fertile zone in the midregion, and ultimate-type vegetative leaves in the distal region. Axillary ovuliferous dwarf shoots of the compound fertile zones correspond to ultimate branches of the vegetative systems. Compound pollen cones are terminal on branches. These and supplementary data from previously described walchian species reveal that the architecture of the most primitive conifers resembles juvenile araucarian conifers and suggest that giant conifers evolved from diminutive trees by the combination of an extended vegetative growth phase and hypermorphoses in leaf development. [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]