Carboniferous Fern Research Articles

Rapid diversification of vascular architecture underlies the Carboniferous fern radiation.

Vascular plants account for 93% of Earth's terrestrial flora. Xylem and phloem, vital for transporting water and nutrients through the plant, unite this diverse clade. Three-dimensional arrangements of these tissues (vascular architecture) are manifold across living and extinct species. However, the evolutionary processes underlying this variation remain elusive. Using ferns, a diverse clade with multiple radiations over their ca 400-million-year history, we synthesized data across 3339 species to explore the tempo and mode of vascular evolution and to contextualize dynamics of phenotypic innovation during major fern diversification events. Our results reveal three paradigm shifts in our understanding of fern vascular evolution. (i) The canonical theory on the stepwise and unidirectional evolution of vascular architecture does not capture the complexities of character evolution among ferns. Rather, a new model permitting additional transitions, rate heterogeneity and multiple reversions is more likely. (ii) Major shifts in vascular architecture correspond to developmental changes in body size, not regional water availability. (iii) The early Carboniferous radiation of crown-group ferns was characterized by an explosion of phenotypic innovation. By contrast, during the Cretaceous and Cenozoic rise of eupolypods, rates of vascular evolution were dramatically low and seemingly decoupled from lineage diversification.

3D Chemometric Model Simulating the Acitheca Polymorpha Frond: Implications for Reconstructing Carboniferous Ferns (Marattiales, Canada)

Abstract Reported are results of an initial approximate imitation of a Carboniferous fern frond, i.e., marattialean Acitheca polymorpha (Schimper), Middle Pennsylvanian Sydney Coalfield, Canada. The simulation experiment is based on the analysis of 14 infrared spectra obtained by means of Fourier Transform Infrared spectroscopy from four detached fragments of sterile polymorphic penultimate-pinna compressions. The calculated relative, semi-quantitative, chemical data from the infrared spectra are the input for principal component analysis deriving a 3D (three-dimensional) chemometric model. To interpret it, the four specimens are placed in hypothetical-frond positions simulating a tripinnate frond, based on diminishing penultimate-rachial widths from 1-mm (distal) to 10-mm (proximal). Hypothetical conclusions include position-dependent chemistries, specifically that of opposing trends of aromaticity vs. aliphaticity in pinnules-rachises. This, in turn, would suggest potential for (i) fern-frond reconstruction, and (ii) for determination of a most likely frond position of fragmentary specimens by “chemical classification”; the predictive aspect. However, further experimental refinement is necessary particularly based on larger frond segments to confirm or disconfirm the overall hypothetical results.

Celebrating Women in Paleobotany: A Tribute to Edith L. Taylor—Introduction and Dedication

Celebrating Women in Paleobotany: A Tribute to Edith L. Taylor—Introduction and Dedication

REINVESTIGATING CARBONIFEROUS "ACTINOMYCETES": AUTHIGENIC FORMATION OF BIOMIMETIC CARBONATES PROVIDES INSIGHT INTO EARLY DIAGENESIS OF PERMINERALIZED PLANTS

Paleoecological interactions among fossil microorganisms have garnered significant interest within the paleobotanical community; however, an understanding of the early diagenesis of associated plant material is of critical importance when assessing putative body fossils of fungi and bacteria. Structures preserved within permineralized petioles of the Carboniferous fern Botryopteris tridentata Felix (Scott) have been interpreted as the earliest remains of Actinobacteria found in association with vascular plants, but re-examination of the specimens indicates instead that these biomimetic structures (BMS) are authigenic carbonate minerals. Using spinning disk confocal microscopy, we generated monochromatic luminescence maps of BMS found within the phloem cells of Botryopteris. Luminescence was captured at wavelengths of 665 nm, consistent with an interpretation of these structures as disordered dolomites, an inference subsequently corroborated with energy-dispersive X-ray spectrometry (SEM-EDS). The presence of high-magnesium carbonates within Botryopteris is suggestive of an early anaerobic stage of plant tissue degradation characterized by metabolic activities of sulfate-reducing bacteria. Anaerobic biodegradation may also have been performed by chytridiomycetes, and we interpret larger (5–8

Description of synangia and spores of the holotype of the Carboniferous fern Lobatopteris miltoni, with taxonomic comments

Pinnules of the holotype of Filicites miltoni Artis (Duckmantian–early Moscovian, Middle Pennsylvanian age) have two rows of synangia, one on each side of the midvein. Each synangium is borne on a short receptacle and consists of three or four claviform sporangia that are separated from each other along most of their length. The sporangia contain trilete spores with a microverrucate to microgranulate exine. F. miltoni appears to be congeneric with the syntypes of Pecopteris vestita Lesquereux, which is the type species of the morphogenus Lobatopteris Wagner.

Cuticles and spores of Senftenbergia plumosa (Artis) Bek and Pšenička from the Carboniferous of Pilsen Basin, Bohemian Massif

Senftenbergia plumosa (Artis) Bek and Pšenička is an abundant Carboniferous fern occurring in the Central and Western Bohemian Carboniferous basins of the Czech Republic. Its epidermal structures are described in detail for the first time. The abaxial cuticles are very thin. The cells are isodiametric, random, pentagonal or hexagonal in shape. Stomata occur only on the abaxial side of the pinnules. They are irregularly scattered and more or less oriented in one direction; ca. 200 per mm 2, of the actinocytic or cyclocytic, flush with the epidermal cells. The abaxial and adaxial surfaces contain small trichome bases. Sporangia are of the Senftenbergia type with Raistrickia type spores. These are different from those of the previously described fertile specimens of S. plumosa from Bohemia, suggesting a large morphological variability of spores in this species. The epidermal structures of S. plumosa are important for understanding the systematic position of this Carboniferous fern. Generally, the cuticle of S. plumosa is more similar (especially its irregularly, polygonal cells with straight anticlinal wall and cyclocytic stomata) to that of living species of Marattiaceae than of Schizaeaceae. The epidermal cells of S. plumosa are very similar to those of the Tedelea glabra. It appears to confirm that S. plumosa is a member of the primitive Carboniferous fern family Tedeleaceae (Jennings and Eggert, 1977; Taylor and Taylor, 1993; Bek and Pšenička, 2001).

Chemotaxonomy for naturally macerated tree-fern cuticles (Medullosales and Marattiales), Carboniferous Sydney and Mabou Sub-Basins, Nova Scotia, Canada

Naturally macerated cuticles (NMC) and one synangium, representing medullosalean and marattialean tree-fern species, from two Carboniferous coalfields in Nova Scotia, Canada, are investigated. The samples were analyzed by infrared spectroscopy (FTIR), and by pyrolysis-gas chromatograph/mass spectrometry (py-Gc/Ms) techniques in search for chemical signatures that would help in developing a chemotaxonomic classification of Carboniferous fern species, assuming genetically dependent make-up of cuticles. FTIR-derived CH 2/CH 3 ratios, in conjunction with contributions from carboxyl groups, demonstrated a better potential for discriminating between medullosalean genera and species than molecular signatures obtained by py-Gc/Ms. However, the latter provided better data for differentiating medullosalean from marattialean tree ferns as a group. Changes in the chemical make-up of naturally macerated cuticles due to sample preparation are discussed.

The ultrastructure of the exine of the megaspores in two palaeozoic seed-like structures

The exine of Cystosporites devonicus Chaloner and Pettitt (1964), a Devonian seed-megaspore, and Didymosporites scottii Chaloner (1958), a Carboniferous fern tetrad, are investigated using SEM, TEM and laser scanning microscopy. C. devonicus is shown to have a homogeneous exine structure and in this respect is different from all other members of this genus (lycopod seed megaspores), which have a fibrous exine. The genus Spermasporites is erected to accommodate Devonian, Cystoporites-like tetrads with a homogeneous exine. The new combination Spermasporites devonicus (Chaloner et Pettitt) Hemsley has been made. The exine of the functional spores of Didymosporites is also simple in structure but the bag of tapetal material surrounding the tetrad is complex and is suggested to be analogous, and possibly homologous, with the tapetal membrane of gymnosperms.

The Fine Structure of Fossil Plant Cell Walls

The cell walls of sieve elements in the primary phloem of the Carboniferous fern Tubicaulis contain structural features that morphologically resemble cellulose microfibrils in extant plants. This may be the oldest example of distinct fibrillar structures in the fossil record. The possible identity and significance of these features are discussed and their structure is compared with that of cell walls in other fossil and extant plants.

New Observations on the Branching of Carboniferous Ferns and Pteridosperms

Additional information is presented on the oldest known example of axillary branching seen in some Calamopitys from the lowermost Carboniferous of France; these putative pteridosperms are amongst the earliest plants to be attributed to the spermatophytes. Comparative anatomical studies of coenopterid ferns from the Lower and Upper Carboniferous show four categories of cauline branching morphology: unbranched, dichotomous, lateral-monopodial and branches borne on leaves. It is suggested that leaf evolution and thus, the axillary type of branching, was achieved earlier in the pteridosperms than in the ferns.

Some American Carboniferous Fern Fructifications

Some American Carboniferous Fern Fructifications

The President's Address: What were the Carboniferous Ferns?

The President's Address: What were the Carboniferous Ferns?

On the fertile fronds of Crossotheca and Myriotheca, and on the spores of other Carboniferous ferns, from Mazon Creek, Illinois

On the fertile fronds of Crossotheca and Myriotheca, and on the spores of other Carboniferous ferns, from Mazon Creek, Illinois

I. On the Fructification and Internal Structure of Carboniferous Ferns in their Relation to those of Existing Genera, with Special Reference to British Palæozoic Species

I have great pleasure in acceding to the request of your Secretary to bring this paper before the members of the Geological Society of Glasgow, especially as immediately surrounding this city are large coal-fields, rich in the remains of the extinct flora which is to engage our attention for a short time this evening. This paper has been suggested to me from a question often asked by beginners in the study of Palaeozoic Botany, “In what book can I find the descriptions of British species?” Unfortunately this question cannot be answered, as no complete work on the British Palaeozoic flora has yet been published, and what has been written on the subject is, with few exceptions, scattered through the Transactions of various Societies which are frequently inaccessible to students of fossil botany, except to those in some of our large centres of population. But let us suppose that the beginner has access to all papers hitherto published on British palaeozoic botany, none the less will he soon meet with species which, if previously recorded from Britain, are certainly not described in any English work. One therefore must make their identifications in great part from the writings of foreign authors. These volumes are expensive, and as very few of our libraries contain even some of the standard works on the subject, fossil botany in Scotland, and I might even say in Britain generally, has been but little studied. There are many intelligent collectors of fossil plants, but till there is a This 250-word extract was created in the absence of an abstract