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

Premise: 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]

Abstract: More than 50 specimens of permineralized fertile pinnules with abaxially borne sporangia have been discovered in calcareous marine nodules from the Upper Cretaceous (Coniacian) Comox Formation from the Eden Main localities on Vancouver Island, British Columbia, Canada. Isolated pinnules 1.6–3.0 mm wide×1.6–2.8 mm long are lobed and abaxially enrolled to form irregular globose structures. Pyriform sporangia 216–300 μm wide×360–468 μm long occur in two rows on the abaxial surface of pinnule lobes. Sporangia have an apical annulus of 15–18 cells. Spores are tetrahedral and trilete, 33–42 μm in diameter, with straight to concave interradial sides, laesurae extending nearly to the equator, and a psilate exine. Spores are assignable to the sporae dispersae genus Deltoidospora. Fertile pinnules are compared to fossils of Anemia poolensis and two previously described species of Paralygodium, and show closest similarities to P. vancouverensis from the Eocene of British Columbia. The Cretaceous Eden Main specimens differ in number of pinnule lobes and their morphology and are described as a new taxon: P. meckertii sp. nov. This discovery extends the Cretaceous geographic range of Paralygodium from Japan to North America and adds to our knowledge of the diversity of extinct schizaeaceous ferns. [Copyright &y& Elsevier]

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. [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]

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

Anatomically preserved foliage of a dipteridaceous fern has been identified in both calcareous nodules and fine-grained, carbonate-cemented sandstone from the early Cretaceous (Hauterivian-Barremian) Apple Bay locality from Vancouver Island, British Columbia, Canada. Fronds with attached sporangia containing spores are preserved as both compression/impressions and as permineralizations. Fan-shaped laminar segments display paired teeth along the margin. Major veins dichotomize to the lamina edge, and finer veins reticulate, forming square to polygonal areoles, with freely ending veinlets. Veins are enclosed by sclerenchymatous sheaths, and the abaxial epidermis is recessed, producing concave areas between veins. Adaxial cuticle is thick, and the epidermis contains rectangular cells with undulating walls. Anomocytic scattered stomata occur on the abaxial surface. Sporangia and trichomes are scattered across the abaxial epidermis in the areolar concavities. Sporangial stalks are short, two to three cells long and four to six cells wide throughout their length. Sporangia have a vertical annulus that is interrupted by the stalk, and they contain trilete spores that correspond to Cibotiumspora jurienensis. Leaf morphology is similar to that of extant Dipteris novoguineensis and fossil Hausmannia spp. A unique combination of characters demonstrates that Hausmannia is a distinct genus of fossil dipterids. An examination of leaves from extant Dipteris rhizomes of various ages suggests that the genus Protorhipis may represent juvenile Hausmannia at some localities. The association of Hausmannia with small pieces of delicate moss gametophytes, fern sporelings, and vegetative remains of Lycopodium and Selaginella at Apple Bay reinforces the interpretation that these fossil dipterids were deposited under storm conditions and that Hausmannia may have grown in disturbed habitats. [ABSTRACT FROM AUTHOR]

Trawetsia princetonensis Smith, Stockey, Nishida & Rothwell gen. et sp. nov. is described from several permineralized rhizomes, stipes, and higher-order frond members of a blechnoid fern that have been identified from the Middle Eocene Princeton Chert of British Columbia. Rhizomes bear stipes arising from all sides of the stem as well as diarch adventitious roots. The dictyostelic rhizomes are up to 16 mm across and have five to seven amphiphloic cauline bundles that are capped internally and externally by sclerenchyma. Ground tissue, where well preserved, is transitional from arenchymatous toparenchymatous, with abundant small sclerotic nests found throughout the pith and cortex. Multicellular scales are borne on the rhizome but are sparse and do not imbricate. At least three orders of frond material are preserved: stipes, primary pinnae, and laminar pinnules. Stipes have an adaxial groove, two adaxial hippocampiform bundles, and seven or fewer small, circular bundles arranged in an abaxial U-shaped arc. In distal sections of the rachis, the vascular bundles are reduced to three or fewer. Ground tissue of the stipe has sclerenchyma nests near the base but distally becomes completely aerenchymatous, further evidence that the Princeton Chert preserves an ancient wetland environment. This fossil material expands our knowledge of fern diversity from the Princeton Chert locality, which also includes osmundaceous, dennstaedtioid, and dryopterid ferns, and it contributes to the understanding of the timing and evolution of derived Filicales. While the vegetative anatomy of this fern allies it with the Blechnaceae, the lack of attached fertile fronds precludes the possible recognition of T. princetonensis as a fossil representative of a modern genus or perhaps even a living species. [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]

The Lower Cretaceous (Valanginian to Hauterivian) Apple Bay locality on Vancouver Island, British Columbia, has yielded several fragments of fertile permineralized osmundaceous pinnae. Specimens are preserved in calcareous concretions, showing both internal anatomy and allowing for the reconstruction of external morphology. Sporangia are borne laterally and clustered along terete pinna segments. They range from 550 to 650mm in diameter, with a lateral annulus that is nine to 12 cells wide and two to three cells high and is separated from the stalk by only one or two cells. Spores are spheroidal and trilete, 40-52 mm in diameter, with long laesurae and a coarsely tuberculate exospore. Some tubercles are fused, forming microrugulae. Sporangial structure and spores most closely resemble those of Osmunda L. These fossils, described as Osmunda vancouverensis sp. nov., add to our growing appreciation for the antiquity of modern Osmundaceae and underscore the potential of the numerous well-preserved fern fossils from Apple Bay to enhance our understanding of the phylogeny of Filicales. [ABSTRACT FROM AUTHOR]

A distinctive new permineralized stem from marine deposits of western North America provides additional evidence for the diversity of Upper Cretaceous tree ferns. The fossil occurs in a calcareous concretion from the Late Campanian Spray Formation at Shelter Point, Vancouver Island, British Columbia, Canada. It measures 20 cm long and 7 cm in maximum diameter, with adventitious roots diverging between persistent, helically arranged fronds. Frond traces are derived from an amphiphloic dictyostele, and the stem produces no medullary or cortical bundles. The pith has a sclerenchymatous center and a parenchymatous outer zone. Sclerenchyma sheaths accompany both cauline and foliar vasculature. Frond traces diverge as six to ten bundles, most often eight. At the stem periphery, the cortex produces a homogeneous sclerenchymatous hypodermis, and is clothed by a dense ramentum of both uniseriate and large multiseriate trichomes. This novel combination of characters reveals the presence of a new genus and species of tree ferns, Rickwoodopteris hirsuta gen. et. sp. nov. Cladistic analysis of stem characters infers that R. hirsuta conforms to the dicksoniaceous grade of Cyatheaceae s.l., and further clarifies our understanding of evolutionary diversification among Mesozoic filicalean tree ferns. [Copyright &y& Elsevier]

Studies a species of the osmundaceous fern Millerocaulis from the Early Cretaceous, Upper Chickaballu Member of the Budden Canyon Formation in California. Comparison to living and fossil ferns in the family Osmundaceae; Stem characteristics; Root traces; Genera with the closest similarity to the specimen.

The article offers information on the evolution of modern fern such as leptosporangiate fern. The history of the fern's systematic classification has gone through constant changes as the number of recognized living families range from nine to more than 40 with the additional extinct families in the fossil record. The recent advancements of systematically informative structural characters and the development of molecular systematics have allowed pteridologist to recognize grades and biological groups of ferns with increasing confidence. They have also defined families of living species that traditionally have been hard to identify from fossils.

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]