The environmental distribution of late proterozoic organisms
Along present day coast lines, the environmental distributions of prokaryotic and protistan populations are often sharply delimited. Realized habitat ranges are generally narrower than those circumscribed by physiological tolerances, suggesting the importance of organism-organism interactions in the...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19920004419 2023-05-15T18:29:45+02:00 The environmental distribution of late proterozoic organisms Knoll, A. H. Unclassified, Unlimited, Publicly available Oct 1, 1991 application/pdf http://hdl.handle.net/2060/19920004419 unknown Document ID: 19920004419 Accession ID: 92N13637 http://hdl.handle.net/2060/19920004419 No Copyright CASI SPACE BIOLOGY NASA, Washington, Fourth Symposium on Chemical Evolution and the Origin and Evolution of Life; p 73 1991 ftnasantrs 2015-03-15T05:00:49Z Along present day coast lines, the environmental distributions of prokaryotic and protistan populations are often sharply delimited. Realized habitat ranges are generally narrower than those circumscribed by physiological tolerances, suggesting the importance of organism-organism interactions in the determination of population distributions. Microfossil populations preserved in silicified carbonates, dolomites, and shales of the 700-800 Ma old Akademikerbreen Group, Svalbard, and elsewhere indicate that the environmental distributions were defined equally clearly during the Proterozoic Eon. The Draken Conglomerate Formation is a tidal flat/lagoonal complex in which we have distinguished five principle biofacies containing a total of 42 taxa. Supratidal to subtidal gradients include the increasing abundance and diversity of both mat dweller microbenthos and allochthonous (principally planktonic) organisms, as well as a taphonomically important pattern of decreasing sheath thickness among mat builder microorganisms. The seaward barriers of Akademikerbreen lagoons were oolitic shoals, and these contain about a dozen endolithic and epilithic species not observed elsewhere in the group. Subtidal environments below fair weather wave base are represented by mudstones of the Svanbergfjellet Formation. These contain abundant and diverse cyanobacteria-like fossils generally similar to but specifically different from those found in tidal flat sediments, as well as diverse unicellular protists (some of impressive morphological complexity) and at least half a dozen cellularly preserved metaphyte populations. In all, more than 80 species are distributed among Akademikerbreen lithologies. Fossil assemblages from Svalbard and elsewhere illustrate the potential for a much finer paleoecological, biostratigraphic, and, hence, evolutionary resolution of the early fossil record. Other/Unknown Material Svalbard NASA Technical Reports Server (NTRS) Svalbard Akademikerbreen ENVELOPE(18.391,18.391,78.718,78.718) Svanbergfjellet ENVELOPE(18.194,18.194,78.682,78.682) |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
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topic |
SPACE BIOLOGY |
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SPACE BIOLOGY Knoll, A. H. The environmental distribution of late proterozoic organisms |
topic_facet |
SPACE BIOLOGY |
description |
Along present day coast lines, the environmental distributions of prokaryotic and protistan populations are often sharply delimited. Realized habitat ranges are generally narrower than those circumscribed by physiological tolerances, suggesting the importance of organism-organism interactions in the determination of population distributions. Microfossil populations preserved in silicified carbonates, dolomites, and shales of the 700-800 Ma old Akademikerbreen Group, Svalbard, and elsewhere indicate that the environmental distributions were defined equally clearly during the Proterozoic Eon. The Draken Conglomerate Formation is a tidal flat/lagoonal complex in which we have distinguished five principle biofacies containing a total of 42 taxa. Supratidal to subtidal gradients include the increasing abundance and diversity of both mat dweller microbenthos and allochthonous (principally planktonic) organisms, as well as a taphonomically important pattern of decreasing sheath thickness among mat builder microorganisms. The seaward barriers of Akademikerbreen lagoons were oolitic shoals, and these contain about a dozen endolithic and epilithic species not observed elsewhere in the group. Subtidal environments below fair weather wave base are represented by mudstones of the Svanbergfjellet Formation. These contain abundant and diverse cyanobacteria-like fossils generally similar to but specifically different from those found in tidal flat sediments, as well as diverse unicellular protists (some of impressive morphological complexity) and at least half a dozen cellularly preserved metaphyte populations. In all, more than 80 species are distributed among Akademikerbreen lithologies. Fossil assemblages from Svalbard and elsewhere illustrate the potential for a much finer paleoecological, biostratigraphic, and, hence, evolutionary resolution of the early fossil record. |
format |
Other/Unknown Material |
author |
Knoll, A. H. |
author_facet |
Knoll, A. H. |
author_sort |
Knoll, A. H. |
title |
The environmental distribution of late proterozoic organisms |
title_short |
The environmental distribution of late proterozoic organisms |
title_full |
The environmental distribution of late proterozoic organisms |
title_fullStr |
The environmental distribution of late proterozoic organisms |
title_full_unstemmed |
The environmental distribution of late proterozoic organisms |
title_sort |
environmental distribution of late proterozoic organisms |
publishDate |
1991 |
url |
http://hdl.handle.net/2060/19920004419 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(18.391,18.391,78.718,78.718) ENVELOPE(18.194,18.194,78.682,78.682) |
geographic |
Svalbard Akademikerbreen Svanbergfjellet |
geographic_facet |
Svalbard Akademikerbreen Svanbergfjellet |
genre |
Svalbard |
genre_facet |
Svalbard |
op_source |
CASI |
op_relation |
Document ID: 19920004419 Accession ID: 92N13637 http://hdl.handle.net/2060/19920004419 |
op_rights |
No Copyright |
_version_ |
1766213096233238528 |