Late Paleozoic bisaccate pollen from the Midcontinent area /
by Katherine Maude Marie Schaeffer.
Description
- Language(s)
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English
- Published
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1960.
- Summary
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Pollen grains are the male gametophyte generation of the life cycle of seed-producing plants. Bisaccate pollen is distinguished from other pollen types by separation of the two opposite portions of the outer layer (sexine) from the underlying layer (nexine), thus producing air-sacs or bladders. The process of fossilization destroys the protoplasmic constituents and the innermost layer of the wall (intine). However, the remains of the pollen grains are usually sufficiently well preserved and distinctive that they may be classified in form-genera and form-species. Bisaccate pollen is generally believed to have gymnospermic affinities. Extant bisaccate pollen is produced by some species of the coniferalean families Pinaceae and Podocarpaceae and is considered more primitive than nonsaccate pollen in these families. The fossil record of bisaccate pollen ranges from Late Devonian to Recent, with peak abundance and diversification during the Permian and Triassic. Assemblages of Late Paleozoic bisaccate pollen have been described from Germany, the Netherlands, Russia, Australia and India. Little information exists on Late Paleozoic occurrences of bisaccate pollen from the U.S.; while the main purpose of this study is not stratigraphic, occurrences of the described taxa in the U.S. Midcontinent area are given. The following study treats the morphology and classification of bisaccate pollen of Late Pennsylvanian (Virgilian series) through Middle Permian (Leonardian series) age of the U.S. Midcontinent area (Texas, Kansas, and Oklahoma). The study is based upon sixteen samples the majority of which are shales.
- Note
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Advisor: Robert M. Kosanke, Department of Geology.
Vita.
- Physical Description
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v, 83, [1] leaves :
illustrations ;
28 cm
Viewability