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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., (© 2021 Botanical Society of America.)

Premise of the Study: Equisetum is the sole living representative of Sphenopsida, a clade with impressive species richness, a long fossil history dating back to the Devonian, and obscure relationships with other living pteridophytes. Based on molecular data, the crown group age of Equisetum is mid-Paleogene, although fossils with possible crown synapomorphies appear in the Triassic. The most widely circulated hypothesis states that the lineage of Equisetum derives from calamitaceans, but no comprehensive phylogenetic studies support the claim. Using a combined approach, we provide a comprehensive phylogenetic analysis of Equisetales, with special emphasis on the origin of genus Equisetum., Methods: We performed parsimony phylogenetic analyses to address relationships of 43 equisetalean species (15 extant, 28 extinct) using a combination of morphological and molecular characters., Key Results: We recovered Equisetaceae + Neocalamites as sister to Calamitaceae + a clade of Angaran and Gondwanan horsetails, with the four groups forming a clade that is sister to Archaeocalamitaceae. The estimated age for the Equisetum crown group is mid-Mesozoic., Conclusions: Modern horsetails are not nested within calamitaceans; instead, both groups have explored independent evolutionary trajectories since the Carboniferous. Diverse fossil taxon sampling helps to shed light on the position and relationships of equisetalean lineages, of which only a tiny remnant is present within the extant flora. Understanding these relationships and early character configurations of ancient plant clades as Equisetales provide useful tests of hypotheses about overall phylogenetic relationships of euphyllophytes and foundations for future tests of molecular dates with paleontological data., (© 2018 Botanical Society of America.)

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., (© 2018 Botanical Society of America.)

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.

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., (© 2017 Botanical Society of America.)

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., (© 2016 Botanical Society of America.)

Premise of the Study: Triassic and Jurassic fossils record structural changes in conifer seed cones through time, provide the earliest evidence for crown-group conifer clades, and further clarify sister-group relationships of modern conifer families. A new and distinct seed-cone from the Isle of Skye in western Scotland provides the oldest detailed evidence for the ancestral morphology of the phylogenetically contentious family Cupressaceae., Methods: A single isolated cone was prepared as serial sections by the cellulose acetate peel technique, mounted on microscope slides, and viewed and photographed using transmitted light. The three-dimensional structure of the cone was first reconstructed from the serial sections and then refined through imaging with x-ray microtomography., Key Results: Scitistrobus duncaanensis, gen. et sp. nov., is a 7.5 mm-diameter cylindrical seed cone with helically arranged bract-scale complexes in which three scale tips separate from a large bract, each tip bearing one adaxial seed. Seeds are near-inverted, show 180° rotational symmetry, and have a diminutive wing in the major plane., Conclusions: Scitistrobus duncaanensis extends the fossil record for anatomically preserved seed cones of the Cupressaceae backward from the Upper Jurassic to the Aalenian Stage of the Middle Jurassic. The cone displays a previously unknown combination of characters that we regard as diagnostic for seed cones of early-divergent Cupressaceae and helps to clarify the sequence of structural changes that occurred during the transition from ancestral voltzialean conifers to morphologically recognizable Cupressaceae. Hypotheses of homology underpinning such transformational series can be tested by ongoing reciprocal illumination between the morphology of fossil taxa and the morphogenesis and developmental genetics of their extant crown-group relatives., (© 2015 Botanical Society of America, Inc.)

Unlabelled: •, 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 Cunninghamia-like. 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., (© 2014 Botanical Society of America, Inc.)

Premise of the Study: Seed cone morphology and anatomy reflect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affinities with the Cheirolepidiaceae. This paper documents, for the first time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae., Methods: Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specific terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones., Key Results: Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P. patagonica, this pocket-forming tissue is comparable to the flap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family., Conclusions: Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confirms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.

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.

An anatomically preserved fossil fern rhizome with diverging stipe bases and root traces is described from the Lower Cretaceous (Valanginian to Hauterivian) Apple Bay locality, Vancouver Island, British Columbia, Canada. The specimen is assignable to Solenostelopteris Kershaw, a morphogenus with six previously described species. The Apple Bay fossil is 1.3-1.6 mm in diameter, with parenchymatous pith and cortex, and is described as S. skogiae sp. nov. The xylem of the solenostele is exarch and one to six cells thick. Successive stipes diverge from only one side of the rhizome, implying a dorsi-ventral symmetry and prostrate habit. No trichomes or scales are produced. Diarch root traces emerge from all sides of the rhizome, some associated with leaf trace divergence. The pith and cortex are made up of uniform, thin-walled cells. The Apple Bay rhizome is most similar to S. nipanica Vishnu-Mittre from the Lower Cretaceous Nipania Flora, India, but differs in size and in distinctive tissue zonation in the cortex. This new species is the youngest record of the genus Solenostelopteris in North America, and it emphasizes that both new specimens of fossils and more complete descriptions of living ferns are needed to help clarify our concepts of Mesozoic ferns.

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. 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]

This article discusses the proposal to conserve the name Botryopteris Renault against Botryopteris C. Presl. The genus Botryopteris C. Presl was originally established for a single fern species but is now considered a synonym of Helminthostachys. In 1875, Renault established another genus called Botryopteris, which is a common and widespread fossil-genus. The authors argue for conserving the name Botryopteris Renault due to its established usage and importance in palaeobotanical research. They believe that maintaining the stability of the name will benefit researchers in their work. [Extracted from the article]