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ABSTRACTFly-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.

Two fossil poroid hymenophore fragments, one from the Cretaceous Period and the other from the Eocene Epoch, are described. The permineralized specimens were obtained from marine calcareous concretions on Vancouver Island, British Columbia, Canada, and were studied using the cellulose acetate peel technique. Size and distribution of pores in the hymenophores, as well as the hyphal anatomy of the dissepiments and some hymenial elements, were examined. In the Cretaceous specimen, Quatsinoporites cranhamiisp. nov., pores are round to elliptical, three per mm, and 130–540 μm diam. Dissepiments consist of narrow, simple septate, hyphae. Neither basidia nor basidiospores are present, but acuminate hymenial cystidia, up to 54 μm in length, are common. The Eocene specimen, Appianoporites vancouverensissp. nov., has a pore density of six per mm and pores are 130–163 μm in diam. Dissepiments consist of narrow, simple septate, thin-walled hyphae. Neither basidia nor basidiospores are present, but acuminate, thick-walled hymenial cystidia, up to 32 μm in length, are common. The poroid hymenophore is a characteristic of a number of extant basidiomycete taxa, including the Boletales, Polyporales and Hymenochaetales. It is unlikely that the fleshy, ephemeral, terrestrial basidiomata of the Boletales would be preserved in a marine environment, and thus the specimens are interpreted as belonging to basidiomycete lineages, with persistent, leathery or corky basidiomata. The simple septate hyphae, the minute pores and presence of cystidia most closely resemble taxa of the Hymenochaetales. These fossils unequivocally push back the minimum age of homobasidiomycetes and extend their paleogeographical range.

Conantiopteris schuchmanii: gen. et sp. nov. The specimen, 23.2 cm long and 11.7 cm wide, shows helically arranged persistent frond bases embedded in adventitious roots, and is clothed by multicellular trichomes. A parenchymatous pith with mucilaginous cells and sclerotic nests is surrounded by an amphiphloic distyostele, parenchymatous inner cortex, and outer sclerenchymatous cortex. Sclerenchyma also surrounds the cauline vasculature and leaf traces. Medullary and cortical bundles are absent. Phloem contains both axially elongated and tangential sieve elements. Frond bases are oval in outline with three vascular bundles, including an undulating abaxial arc and an adaxial pair. Protoxylem of the stipe is endarch and is associated with cavity parenchyma. These characters are indicative of tree fern affinities. A cladistic analysis using trunk characters of both living and fossil tree ferns was conducted to help establish relationships of the new species and other fossil ferns, and to test hypotheses of general tree fern relationships. Additional analyses of living taxa only were also performed. Results from the analysis using both living and fossil taxa compare favorably with those that included only living species when either morphological characters or molecular sequences of the chloroplast gene rbcL are utilized. Although there are variations in the topologies of the various trees, results indicate that the new genus is nested among a paraphyletic assemblage of dicksoniaceous, lophosoriaceous, and metaxyaceous species that subtend a monophyletic Cyatheaceae s.s.

Abstract: The Southern Hemisphere conifer family Araucariaceae has a very restricted present day distribution, but was more widespread in the past. The genusAraucaria is represented by good fossil material in both hemispheres as early as the Jurassic, whileAgathis is only known from the Southern Hemisphere beginning in the Cretaceous. Cuticle studies of extant araucarians have enabled accurate comparisons of fossil leaves to living taxa.Araucaria SectionBunya is represented by cones of several types in the Jurassic. In addition to these remains, a suite of araucarian cones showing affinities to several sections of the genusAraucaria have been described from England, Japan and North America. Evidence that fossil araucarian cones may have produced seeds with hypogeal germination is discussed in light of recent work on germination of extant bunya seedlings and the discovery of new fossil shoots from the Jurassic Morrison Formation of Utah.

A permineralized flower bud, two stamen clusters and one isolated stamen of similar morphology have been found in the black cherts of the Middle Eocene Allenby Formation of Princeton, British Columbia. Specimens were studied using a modified cellulose acetate peel technique and hydrofluoric acid. The single flower specimen, 4.5 mm long and 4.0 mm in diameter, represents half of a relatively mature bud of a bisexual flower with a superior ovary. The two‐loculate pistil is 2.5 mm long with a solid style and a lobed stigmatic surface. No ovules have been observed in attachment. Twenty‐two to 24 stamens are borne in three whorls or a tight helix. Pollen sacs of the anther are elongate with a thin connective while filaments are laminar. Anther walls contain rectangular cells with dark contents that also can be identified in isolated stamens or stamen clusters. Abundant stephanocolpate (pentacolpate), psilate pollen grains 20 μm in diameter have been isolated and examined using scanning and transmission electron microscopy. Grains are tectate, columellate with a broad foot layer that thins near the apertures, and an endexine of small platelets. The remains of four petals are surrounded by one large sepal, suggesting two in the whole flower. Morphological features of this flower are comparable to taxa of the Flacourtiaceae and Papaveraceae, but show closest similarities to the Eschscholziaeae of the Papaveraceae. Difficulties with reconciling the placement of this flower in the Eschscholziaeae and the known environment of deposition of the Princeton chert are discussed. The fossil material represents a new angiospermous taxon: Princetonia allenbyensisStockey gen. et sp. nov., family Incertae sedis.

Fossil seedlings and seeds of an extinct Cercidiphyllum‐like plant occur in the Paskapoo Formation (Late Paleocene) at Joffre Bridge near Red Deer, Alberta. Cotyledon and early seedling leaf stages are preserved in growth position. Morphological details of seedlings and seeds support a close relationship between the Paleocene fossils and extant Cercidiphyllum,and suggest that during the Upper Cretaceous and Tertiary (Paleogene) Cercidiphyllum‐like plants were important early colonizers of open flood‐plain environments.

Seventy‐two silicified cone specimens of Pararaucaria patagonicaWieland from the Cerro Cuadrado (Jurassic) petrified forest in Patagonia were studied by use of thin sections and reflected light. Traces from the cone axis stele to the bract and ovuliferous scale are separate at their origins. In cross section the abaxially concave ovuliferous scale trace and massive circular bract trace branch half‐way out into the cone‐scale complex. Two triangular‐shaped bundles of fibers follow the scale trace into the laminar part of the ovuliferous scale. Both surfaces of the ovuliferous scale possess hairs which may have assisted in cone closure. Cones typically contain one flattened, winged seed per ovuliferous scale. Multi‐layered seed integuments are represented by an inner fleshy layer of large cells filled with a black amorphous material, a sclerotesta consisting of wedges or fan‐shaped groups of sclereids oriented at right angles to the seed surface, and a thin, often crushed fleshy layer. Seed wings consist of anastomosing, branched cells resembling glandular hairs and containing many intercellular spaces. Well‐preserved polycotyledonous embryos containing up to eight cotyledons are present in several cones. Tissues of the embryo including the shoot apex, calyptroperiblem, hypocotyl, and cotyledons are described. On the basis of anatomical and morphological features, specimens of P. patagonicaare compared to members of both extant and extinct families of conifers including the Araucariaceae, Taxodiaceae, Pinaceae, Cupressaceae, and Cheirolepidaceae.

Seeds and embryos contained within the silicified ovuliferous cone Araucaria mirabilisfrom the Cerro Cuadrado petrified forest are described. One wingless seed, 0.8–1.3 cm in length and 0.2–0.6 cm in width, is embedded in each ovuliferous scale. Seeds show a three‐layered integument and a prominent wavy nucellus which is attached basally to the endotesta. The megagametophyte contains cellular inclusions that may represent starch grains. Ovule vascularization is complex and appears most similar to that of Araucaria bidwillii.Embryos 2 mm long and 0.25 mm wide appear to be in a telo‐stage period of development. Shoot apex, cotyledons, root meristem, and calyptroperiblem are present in the embryos in which vascular tissues and secretory elements were beginning to differentiate at the time of fossilization. Embryo ontogeny is considered in light of stages encountered in extant gynmosperm taxa. The absence of the microgametophyte phase in the Cerro Cuadrado collection is discussed.

Three fragments of fascicles of a possible five‐needle pine are described from the Upper Cretaceous Yezo Group (Santonian/Senonian) of Hokkaido. Specimens from the Omakizawa, Oyubari, Yubari City, the Koyanozawa, Ikushumbetsu, Mikasa City, and the Sankebetsugawa, Haboro are preserved in calcium carbonate nodules containing abundant ammonites. Leaves borne in apparent fascicles of five measure 0.7–0.8 mm in radial and 0.8–1.0 mm in tangential diam and are represented by short fragments of isolated needles. Thick‐walled epidermal cells on these amphistomatic leaves resemble the underlying uniform hypodermis. Two external resin canals are situated near the lateral corners toward the adaxial surface. Only slightly plicate mesophyll cells in a layer one to two cells thick border on an elliptical endodermis with thickened outer cell walls. Two to three layers of transfusion tissue surround the double vascular strand. Two vascular bundles are separated by one cell layer of sclerenchyma fibers. Small patches of abaxial and adaxial sclerenchyma fibers have also been observed. Leaves most closely resemble those of Pinus leiophyllaSchl. et Cham. Subgenus Pinus,Section Pinea,Subsection Leiophyllaeand P. montezumaeLamb. Subgenus Pinus,Section Pinus,Subsection Ponderosaeand are described as a new species P. hokkaidoensissp. nov. Stockey and Ueda. Close anatomical comparisons are made with this leaf and previously described permineralized Upper Cretaceous pine needles from Hokkaido and eastern North America.

Some of the most conspicuous fruit and seed remains from the Middle Eocene Princeton chert locality (Allenby Formation) are assignable to the Araceae. Several thousand campylotropous, reniform, spiny seeds 2.5–3.2 mm long x 1.8–2.3 mm wide have been found dispersed in the chert. Two fruits, each with a single locule and at least eight ovules, show three distinct wall layers and appear to have been fleshy. The two layers of seed integument have pitted isodiametric sclereids aligned in radial rows, the outermost being thinner walled. Spines are borne in three rows on the dorsal seed surface while the ventral side is flattened. Idioblasts that probably contained raphides are present in the outer integument. Nucellar tissue is attached to the integument for most of its length and is well‐preserved in some seeds near the chalaza and in the large conical shaped area beneath the micropyle. Endosperm cells with dark contents and curved, linear, monocotyledonous embryos are present in some seeds. Sections of seeds of living araceous taxa of the subfamilies Monsteroideae (Epipremnum, Rhodospatha) and Lasioideae (Urospatha, Cyrtosperma) were made for comparison. The fossil seeds represent a new taxon most closely related to Cyrtosperma, Keratosperma allenbyensisCevallos‐Ferriz et Stockey gen. et sp. nov., Family: Araceae, Subfamily: Lasioideae, Tribe: Lasieae. The Princeton remains are the oldest described seeds of this tribe known to date and add to our knowledge of the subtropical elements of the Princeton flora.

Heterangium kentuckeyensissp. nov. is described from Lower/Middle Pennsylvanian sediments of eastern Kentucky, based on permineralized stems, petioles, frond members, laminar foliage, and roots, including several organs in attachment. Stems 2.2 to 5.8 mm in diameter are known in several developmental stages. The considerable variability in stelar and cortical histology within this one species emphasizes the need to reassess variability within previously described taxa. Fronds of H. kentuckyensisare at least twice pinnate and bear primary pinnae alternately at approximately right angles. Laminar pinnules have dichotomous venation, are at least 2‐lobed, and comparable to foliage of the Sphenopteris‐type. Stomata possess 6–7 subsidiary cells with abaxial papillae. The characters used to distinguish the subgenera of Heterangiumare evaluated and found to be unreliable. Moreover, suggested phylogenetic schemes both within Heterangiumand between this taxon and other lyginopterid pteridosperms based on these features are inconsistent with stratigraphic data. Until reproductive features are known, the classification of Heterangiumspecies is best based on characters of the vegetative sporophyte, including stelar organization (particularly protoxylem architecture), cortical histology, and frond morphology.

Large segments of intact plants that represent a heterosporous fern have been discovered within an aquatic plant community from the Late Cretaceous St. Mary River Formation near Cardston in southern Alberta, Canada. Branching rhizomes of Hydropteris pinnatagen. et sp. nov. are 1–2 mm wide. They produce fronds at intervals of 2–12 mm and bear numerous elongated roots. Fronds, up to approximately 6 cm long, are pinnate with subopposite to alternate pinnae that exhibit anastomosing venation. Large, multisoral sporocarps occur at the junctures of the rhizome and frond rachides. Both microsporangiate massulae and megaspore complexes occur within each sporocarp. Megaspore complexes are assignable to the sporae dispersaegenus ParazollaHall. Microspores are trilete, smooth‐walled, and are embedded in episporal material of the massulae. A numerical cladistic analysis indicates that the heterosporous aquatic ferns are monophyletic, and not as closely related to either schizaeaceous or hymenophyllaceous ferns as they are to some other filicaleans. Systematic revisions are proposed to reflect newly recognized cladistic relationships within the heterosporous clade, and character originations in the evolution of heterosporous aquatic ferns are evaluated. Hydropteridaceae fam. nov. is proposed, and included with Salviniaceae and Azollaceae in the Hydropteridineae subord. nov., and the Hydropteridales Willdenow.

The discovery of numerous specimens of the monostelic pteridosperm genus Microspermopterisin Pennsylvanian coal ball petrifactions from the Lewis Creek and What Cheer localities provides additional information about the anatomical and morphological variability within the genus. Specimens are now known up to 1.1 cm in diam that bear epidermal appendages in the form of variously‐shaped trichomes. The external surface of the stem is further ornamented by longitudinal flaps of cortical tissue. Petioles exhibiting a single C‐shaped vascular strand with abaxial protoxylem are produced in a 2/5 phyllotaxy. Large petiole bases that clasp the stem produce primary pinnae alternately. The presence of axillary branching appears similar to that reported in Callistopliytonand Lyginopteris.Triarch to polyarch adventitious roots, some with secondary tissues, are produced at both nodal and internodal regions. Of the currently recognized monostelic seed fern genera, Microspermopterisis most similar to Heterangium.Information is presented that supports current ideas regarding the evolution of the gymnospermic eustele from protostelic Devonian ancestors.

Vegetative and fertile frond segments of Botrychiumhave been recovered from Paleocene deposits of central Alberta, Canada. Specimens are preserved as coalified compressions that yield information about frond structure, sporangia, and spore ultrastructure. These fossils, described as Botrychium wightoniisp. nov., establish a megafossil record for the Ophioglossales, and demonstrate that modern‐appearing species of the order were present in western North America by the earliest Tertiary. The largest vegetative fragments are up to 4.6 cm long and tripinnately compound, with opposite to subopposite branching. Ultimate segments are pinnatifid with dentate pinnules and open dichotomous venation. Fertile specimens are also tripinnately compound with a long rachis and subopposite to alternate pinnae. Sporangia are either submarginal and superficial, or marginal, and are all directed toward one surface of the pinnule. They are ovoid to subspheroidal and 0.8‐2.0 mm in diameter. Some sporangia are apparently stalked, while others appear to be sessile. This variation results both from the ultimate frond segments being compressed in several different planes, and the fossils being exposed at different levels. Spores macerated from the sporangia are radial and trilete, and range 30–67 μm in diameter. Most are psilate, but some have a densely striate surface.

Cuticle micromorphology of leaves from all five species of the Southern Hemisphere conifer genus Falcatifolium de Laubenfels (Podocarpaceae) was studied with scanning electron microscopy. Both herbarium and preserved specimens were examined and showed no differences in micromorphology. External and internal features of abaxial and adaxial cuticles are characterized for the five species and compared to other known podocarps. External cuticle surfaces exhibit undulating surfaces that may reflect underlying epidermal cell outlines, stomatal plugs composed of irregular blocks, and fairly regular stomatal rows. Stomata are separated by one to three epidermal cells. Two lateral subsidiary cells are present with polar subsidiary cells usually lacking. There is a deep crease in subsidiary cell cuticle, smooth to slightly undulating cuticle on guard cell surfaces near the stoma, a ridge on guard cell cuticle, thin cuticular flanges between guard and subsidiary cells, polar extensions, nonsinuous epidermal cell outlines with cuticle extending to the hypodermis, more elongate epidermal cells between stomatal rows than within rows, and usually granular epidermal cell surfaces.

About 2,000 specimens of infructescences, cymules, fruits, bracts, staminate inflorescences with in situ pollen grains, and leaves assignable to Betulaceae have been collected from the Munce's Hill locality (Paleocene, Paskapoo Formation), Joffre, Alberta. Infructescences are composed of many cymules, each cymule consisting of two fruits. Each fruit is an oval nutlet surrounded by two equal-sized bracts. Bract form varies considerably with respect to size and marginal dissection. Bracts are as deeply dissected and variable as the British type specimen of Palaeocarpinus laciniata Crane from the Paleocene of southern England but usually have one or two lobes instead of several lobes. A short pedicel is present at the base of the fruit, a feature not reported in the British specimens. Furthermore, nutlets have numerous longitudinal striations rather than three longitudinal ribs on their surfaces. Based on the characteristics of nutlets and bracts, these specimens are described as P. joffrensis Sun et Stockey sp. nov. Associated staminate inflorescences are compound catkins composed of many cymules, each consisting of a triangular primary bract, ovate secondary bracts, and numerous stamens. Elongate pollen sacs contain triporate pollen grains with rugulate ornamentation and numerous Ubisch bodies. Transmission electron microscopy reveals a thin foot layer, granular interstitium, and a thick tectum with microchannels. The presence of secondary bracts in inflorescences and aperture characters of the pollen grains show similarity to the genus Corylus. Associated leaves, also resembling Corylus, are ovate to elliptic, with acuminate to attenuate apices, cordate bases, and toothed margins. Six to nine pairs of secondary veins enter the primary teeth with vein endings bending toward the leaf base. Prominent abmedial branches from the secondary veins enter subsidiary teeth. Tertiary and quaternary veins come together at the sinuses, an important feature of Betulaceae. Based on their association and taxonomic affinities, both leaves and-staminate inflorescences are thought to represent detached organs of P. joffrensis.

Cuticle micromorphology from all 21 species of the Southern Hemisphere conifer genus Agathis Salisbury was studied with scanning electron microscopy. External and internal features of abaxial and adaxial cuticles are characterized for the three recognized sections of the genus. External cuticle surfaces of all species are undulating and exhibit Florin rings and stomatal plugs, with most species being hypostomatic. Sunken stomata of various orientations occur in discontinuous rows and have three to nine subsidiary cells, four being the common number, and bilobed polar extensions. Epidermal cells are usually rectangular, but vary considerably even on one leaf. The cuticle on guard and subsidiary cell surfaces is smooth to striated and pitted and can be useful in identifying taxa. Distinguishing characters useful at the levels of genus, section, and species are outlined. Micromorphological features distinguishing Agathis from Araucaria include the undulating epidermal cell surfaces, the presence of Florin rings, stomatal orientations, and bilobed polar extensions. Subsidiary cell number, shape, and morphology and stomatal orientations are the best characters to use when distinguishing fossil araucarian cuticles from those of broad-leaved podocarps.

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