Loading...
Thumbnail Image
Publication

Dordrechtites Arcanus Sp. Nov., An Anatomically Preserved Gymnospermous Reproductive Structure From the Middle Triassic of Antarctica

Bergene, Julie Anne
Taylor, Edith L.
Taylor, Thomas N.
Citations
Altmetric:
Abstract
The genus Dordrechtites is an isolated ovulate structure previously described only from South Africa and Australia as impressions. The discovery of compressed and permineralized specimens of this taxon at the base of Mount Falla (uppermost Fremouw Formation) in the central Transantarctic Mountains extends the geographical and geological distribution of the genus and increases the known floral diversity of the Triassic of Antarctica. The first permineralized species, Dordrechtites arcanus, is described using standard acetate peel techniques and includes internal anatomy of an elongate arm that extends over the top of a central cupule containing two elongate, bilaterally symmetrical, orthotropous ovules. An arc-shaped collateral vascular bundle extends from the arm into the top of the cupule, branches, and then extends around the ovule to about halfway down to the micropylar end. The cupule is parenchymatous and includes transfusion tissue with cells that have pitted walls. The sclerotesta of the ovule is up to 200 mm thick, consisting of an outer layer with longitudinally oriented, thick-walled cells and an inner layer one cell thick of rectangular, thick-walled cells. The micropyle is flared at the attenuated tip of the pyramidal cupule. The four previously described species of Dordrechtites have uncertain affinities, and although the morphology and anatomy of this taxon is now known, the affinities within the gymnosperms are still uncertain.
Description
This is the publisher's version of an article which is being shared with permission. The original version may be accessed at: http://dx.doi.org/10.1086/668792
Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
University of Chicago Press
Research Projects
Organizational Units
Journal Issue
Keywords
Triassic, Gymnosperm, Cupule, Ovules, Central transantarctic mountains
Citation
Bergene, J.A., Taylor, E.L., and Taylor, T.N. 2013. Dordrechtites Arcanus Sp. Nov., An Anatomically Preserved Gymnospermous Reproductive Structure From the Middle Triassic of Antarctica. International Journal of Plant Science 174(2): 250-265.
Embedded videos