Structural adaptation in two Permian brachiopod genera, Salt Range, West Pakistan

Journal of Paleontology
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Abstract

Silicified shells with spines preserved allow analysis of spine distribution as a specific character in the genus Marginifera Waagen and confirm validity of Waagen's (1884) six species. The animal lived with the ventral valve down, the adult shell partly buried, but many spines grew above the substrate prior to burial. Pseudopunctae are interpreted as seats of ciliate papillae or elongate setal follicles, as adaptation to partial burial in soft substrate. Auricular chambers, marginal ridges, and endospines provided effective protection against ingression of coarse or harmful particles. Productus opuntia Waagen is assigned to Echinauris Muir-Wood & Cooper; its habitat and adaptations are interpreted as similar to those of Marginifera. The stratigraphic position of the bed containing the late Permian guide ammonoid Cyclolobus proves to be lower than hitherto thought, thus extending the ammonoid's range. A Guadalupe age for the Chhidru formation is suggested.

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Publication type Article
Publication Subtype Journal Article
Title Structural adaptation in two Permian brachiopod genera, Salt Range, West Pakistan
Series title Journal of Paleontology
Volume 42
Issue 1
Year Published 1968
Language English
Publisher Paleontological Society
Publisher location Bethesda, Maryland
Description 33 p.
First page 1
Last page 32
Country Pakistan
Other Geospatial West Pakistan
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