Paleozoic origin of the cycads /

Megasporophylls and associated plant parts from Upper Pennsylvanian and Lower Permian rocks of southwestern United States are interpreted as lineage of cycads, derived from pteridosperms. Cycadean foliage is thought to be derived from Paleozoic taeniopterids

Bibliographic Details
Main Author: Mamay, Sergius H., 1920-
Corporate Author: Geological Survey (U.S.)
Format: Government Document Book
Language:English
Published: Washington : Dept. of the Interior, Geological Survey : for sale by the Supt. of Docs., U.S. Govt. Print. Off., 1976
Series:Professional paper (Geological Survey (U.S.)) ; no. 934
Professional paper (Geological Survey (U.S.)) 934
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Stanford University

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Call Number: 550.6 .U58P NO.934
I 19.16:934

Johns Hopkins University

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Call Number: I 19.16: 934

Duke University

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Call Number: I 19.16:930-936