Ovule-bearing reproductive organs of the glossopterid seed ferns from the Late Permian of the Beardmore Glacier region, Antarctica
Open-File Report
2007-1047-SRP-082
By: E.L. Taylor, T.N. Taylor, and P.E. Ryberg
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Abstract
The Glossopteridales are an extinct group of seed ferns that dominated Gondwana during the Permian. The
strap-shaped leaves of Glossopteris are widespread and provided early evidence of continental drift, but reproductive
organs of this group have remained enigmatic since they were first described in the 1950s. Based on compression-
impression fossils, there are at least two basic types of ovulate (seed-bearing) organs. In one form, numerous ovules are
borne on the surface of a leaf-like megasporophyll (e.g., Plumsteadia, Dictyopteridium), while the second type consists
of stalked, apparently uniovulate cupules borne on a branching system (e.g., Lidgettonia). More than 30 genera of seed-
bearing organs have been described, many based on compressions or, more commonly, impression fossils, in which it is often impossible to discern the three-dimensional morphology or attachment of these structures. Both morphological types have now been found in permineralized peat from Skaar Ridge, central Transantarctic Mountains (CTM), and provide some of the first anatomical detail of the diversity of reproductive organs of Glossopteris. The multiovulate
organ is small (6 mm wide), with ovules borne on the upper (adaxial) surface; the uniovulate structure consists of four
stalked cupules, each containing a single ovule about 2 mm long. These two forms provide important information about
the diversity of the glossopterids and their status as a natural group of seed plants.
Suggested Citation
Taylor, E., Taylor, T., Ryberg, P., 2007, Ovule-bearing reproductive organs of the glossopterid seed ferns from the Late Permian of the Beardmore Glacier region, Antarctica: U.S. Geological Survey Open-File Report 2007-1047-SRP-082, 4 p., https://doi.org/10.3133/ofr20071047SRP082.
ISSN: 2331-1258 (online)
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Ovule-bearing reproductive organs of the glossopterid seed ferns from the Late Permian of the Beardmore Glacier region, Antarctica |
| Series title | Open-File Report |
| Series number | 2007-1047-SRP-082 |
| DOI | 10.3133/ofr20071047SRP082 |
| Year Published | 2007 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Description | 4 p. |
| Larger Work Type | Report |
| Larger Work Subtype | USGS Numbered Series |
| Larger Work Title | Antarctica: A Keystone in a Changing World--Online Proceedings for the Tenth International Symposium on Antarctic Earth Sciences. Santa Barbara, California, U.S.A.--August 26 to September 1, 2007 |
| Other Geospatial | Antarctica |
| Additional Online Files (Y/N) | N |