Anatomically preserved Glossopteris and Dicroidium from the Transantarctic Mountains [microform]
- Bib ID:
- 3287691
- Format:
- Book and Microform
- Author:
- Pigg, Kathleen Belle
- Description:
- 258 p.
- Summary:
-
Anatomically preserved foliage of Glossopteris and Dicroidium is described from Permian and Triassic strata, respectively, of the Central Transantarctic Mountains, Antarctica. This material provides the first opportunity to detail the anatomy of these two foliage types that dominate the compression/impression fossil flora of Gondwana. Two structurally distinct species of Glossopteris are recognized. One form is characterized by narrow, elongate meshes, a prominent vascular bundle sheath containing fibers, and straight-margined epidermal cells with median papillae. In contrast, the second form has broad, polygonal aeroles, a thick hypodermis, vascular bundles lacking bundle sheath fibers, epidermal cells with sinuous anticlinal walls, and sunken stomata. The diversity in anatomical features of Glossopteris demonstrated in this study provides strong evidence that leaves assigned to this taxon represent a diverse assemblage of plants, rather than a single taxon.
Permineralized Dicroidium foliage is characterized by a bifurcating frond rachis bearing entire pinnae proximally and bipinnatifid pinnae distally. Based on morphological features this material most closely resembles the compression leaf species D. dubium var. australe. The frond rachis is characterized by two groups of vascular bundles, an abaxial ring of 5-8 bundles, and an adaxial group of bundles in a linear arrangement. Anatomical features of Dicroidium foliage, described for the first time, include a well differentiated mesophyll with palisade and spongy layers, scattered resinous cells, fibers, and transfusion tracheids associated with vascular bundles. In many of these features, particularly the frond vascular architecture, the anatomical features of Dicroidium fronds suggest previously unrecognized similarities with the cycads.
- Notes:
-
- (UnM)AAI8824588
- Source: Dissertation Abstracts International, Volume: 49-09, Section: B, page: 3647.
- Adviser: Thomas N. Taylor.
- Thesis (Ph.D.)--The Ohio State University, 1988.
- Reproduction:
- Microfiche. Ann Arbor, Mich.: University Microfilms International.
- Subject:
- Paleobotany
- Other authors/contributors:
- Ohio State University
- Copyright:
-
In Copyright
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Copyright status was determined using the following information:
- Material type:
- Literary Dramatic Musical
- Published status:
- Unpublished
- Creation date:
- 1988
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