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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 68 (1984)

Issue: 4. (April)

First Page: 486

Last Page: 487

Title: Morphological and Morphometric Characterization of Microborings Caused by Heterotrophic Endoliths: ABSTRACT

Author(s): James E. Hook, Stjepko Golubic

Abstract:

Microbial endoliths leave morphologically characteristic and preservable boring traces within carbonate substrates. When cast in resin and studied by scanning electron microscopy, these morphologies can be correlated with distribution, environmental conditions, or geological age of the substrate for use as paleoenvironmental indicators. This paper assesses morphological characteristics of a cluster of ichnotaxa comparable to the description of the genus Dodgella (cladochytrid, lower fungi). These forms have a worldwide distribution in Holocene marine sediments

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and are commonly preserved in fossil shells. The microborings studied have the following morphological elements in common: sac-like enlargements (sporangia) with narrow necks (for spore release) opening to the substrate surface, and fine filaments (hyphae) interconnecting the sporangia.

The following characteristics of these three elements are compared: sporangia--shape, size, direction of the main axis, and degree of complexity; necks--length, cross section, and profile; hyphae--average width, constancy of diameter, branching, and mode of sporangial connection. The separation of three ichnotaxa within this cluster of forms is based on reconstruction of probable life cycles, morphometric analysis on the population level, and identification of the influence of different substrates on the morphology of the borings.

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Copyright 1997 American Association of Petroleum Geologists