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Article: Two new petrified cycad stems, Brunoa gen. nov. and Worsdellia gen. nov., from the Cretaceous of patagonia (Bajo de Santa Rosa, Rio Negro Province), Argentina.
- Article from:
- The Botanical Review
- Article date:
- April 1, 2004
- Author:
CopyrightCOPYRIGHT 2004 New York Botanical Garden. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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I. Abstract
II. Introduction
III. Locality, Materials, and Methods
IV. Systematics
V. Discussion
VI. Conclusions
VII. Literature Cited
II. Introduction
Cycadales are the most primitive order within gymnosperms with extant representatives. The evolutionary history as known from fossils begins in the Upper Paleozoic (Mamay, 1969, 1976; Taylor, 1969; Zhu & Du, 1981) and reaches maximum distribution during the Mesozoic, with decline beginning toward the end of the same period. Presently, Cycadales are a very well circumscribed group consisting of two suborders with three families: Cycadaceae, Stangeriaceae, and Zamiaceae (Johnson, 1959; Petriella ...