Fossil in situ spores and pollen grains: an annotated catalogue

Phylogenetic analysis of seed plants and the origin of angiosperms

Doyle, J.A. (Section of Evolution and Ecology, University of California, Davis, California 95616, USA). Seed ferns and the origin of angiosperms. J. Torrey Bot. Soc. 133: 169–209. 2006.—If molecular analyses are correct in indicating that Gnetales are related to conifers and no other living gymnosperm group is directly related to angiosperms, studies on the origin of angiosperms must focus on fossil taxa, including “seed ferns.” Some authors have homologized the angiosperm carpel with the cupule of seed ferns, but because angiosperm ovules have two integuments rather than one, cupules are more likely to be homologous with the outer integument. Cupules of the earliest seed ferns may be derived from fertile appendages of “progymnosperms,” but those of later taxa appear to be modified leaves or leaflets, with ovules borne on the abaxial surface in some (peltasperms, corystosperms), the adaxial surface in others (glossopterids, Caytonia). Positional relationships and developmental genetic data sugges...

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Seed ferns and the origin of angiosperms

Arborescent lycopod reproduction and paleoecology in a coal-swamp environment of late Middle Pennsylvanian age (herrin coal, Illinois, U.S.A.)

Summary The lack of ecological data concerning the vegetation of the peat deposits and adjoining areas in the Carboniferous period is a limiting factor in the use of spores for stratigraphical purposes. For this reason, a petrological and palynological investigation of a number of coal seams containing crassidurain, in the Yorkshire Coalfield, was undertaken. The results show four distinct assemblages of miospores, each assemblage being more or less associated with coal of a distinctive petrographic type. Their vertical sequence is similar in the different seams. The succession culminates in the crassidurain, above which, under favourable conditions, the sequence is reversed. The peats producing this sequence are considered to be autochthonous in origin although a partly allochthonous coal type is also recognized. Existing theories, which do not take account of palynological evidence, attribute the petrographic differences in the humic coals to varying degrees of aerobic decomposition controlled by environmental factors such as degree of drainage, or depth of water covering the peat surface at the time of deposition. They do not satisfactorily explain all the new evidence. The possibility that at least part of the sequence, and particularly the crassidurain, was the result of climatic factors is suggested.

The palaeoecology of carboniferous peats based on the miospores and petrography of bituminous coals

Fossil plants of the carboniferous rocks of Great Britain

In the month of June last, I communicated to this Society a “Preliminary Note on the Occurrence of Microsporangia in Organic Connection with the Foliage of Lyginodendron.” In the present paper I propose to deal more fully with the subject and to describe and figure the specimens in detail which formed the subject of the preliminary note. There will also be included in this communication the description of a new species of Crossotheca ( C. Hughesiana ), the structure of whose microsporangia is identical with that of Crossotheca Honinghausi , Brongt. sp., and which confirms the observations made on the structure of the microsporangia of that species. Before proceeding it is necessary to make perfectly clear that the plant named Sphenopteris Honinghausi by Brongniart is identical with the Lyginodendron Oldhamium of Williamson. This view is, I believe, generally accepted, but it seems desirable to give the evidence on which I think this relationship is clearly proved.

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On the Microsporangia of the Pteridospermeae, with Remarks on Their Relationship to Existing Groups

Catalogue of the Palaeozoic Plants in the Department of Geology and Palaeontology, British Museum (Natural History)

While working out the flora of the British coalfields, I have found no group of rocks more interesting than the group of sandstones and marls, frequently of a red, purple, or mottled colour, and their associated limestones, which lie above the Middle Coal-Measures of the Potteries Coalfield. When preparing my paper on ‘The Fossil Flora of the Coalfield of the Potteries,’ the classification which I adopted was that used by Mr. John Ward, but at that time little was known about the thickness and stratigraphical relationship of the beds forming this group. The classification adopted by Mr. Ward is as follows:— In the present paper my remarks will be restricted to the rocks here called Permian and Upper Coal-Measures. Any reference that may be made to the underlying group will be merely incidental. At the time when my paper on the fossil flora of the Potteries Coalfield was written, I had seen no plants from the so-called ‘Permian’ of that area, and, in regard to these rocks, Mr. John Ward says, in the work already mentioned:— That these rocks were Carboniferous and not Permian, I felt quite certain: for, apparently, the same so-called ‘Permian’ rocks were passed through while sinking the shaft of the Hamstead Colliery at Great Barr, near Birmingham; they contained a typical Upper Coal-Measure flora; and with this series I classed them at the time. Messrs. F. G. Meachem & H. Insley had previously referred these rocks to the Upper Coal-Measures. I shall have occasion to refer

On the Divisions and Correlation of the Upper Portion of the Coal-Measures, with special reference to their Development in the Midland Counties of England

Robert Kidston

Papers

Fossil plants of the carboniferous rocks of Great Britain

On the Microsporangia of the Pteridospermeae, with Remarks on Their Relationship to Existing Groups

Catalogue of the Palaeozoic Plants in the Department of Geology and Palaeontology, British Museum (Natural History)

On the Divisions and Correlation of the Upper Portion of the Coal-Measures, with special reference to their Development in the Midland Counties of England

A monograph of the calamites of western Europe