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Earliest Evidence for Helical Crown Configuration in a Carboniferous Tree of Uncertain Affinity
Robert A. Gastaldo
Journal of Paleontology
Vol. 64, No. 1 (Jan., 1990), pp. 146-151
Published by: Paleontological Society
Stable URL: http://www.jstor.org/stable/1305554
Page Count: 6
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The crown of an erect plant (probable juvenile tree/shrub) has been recovered from Lower Pennsylvanian strata of the southern Appalachian basin. It is preserved in three dimensions and provides the first confirmatory evidence for the compact helical arrangement of leaves in early Late Carboniferous plants. The crown is partially cast and partially compressed and is comprised of 11 leaves disposed in a 3/5 phyllotaxis. Substantiation of tight helical leaf development restricted to the crown of an Early Pennsylvanian plant provides evidence for greater architectural diversification in growth habit than presently documented at this time in tree ferns or pteridosperms.
Journal of Paleontology © 1990 Paleontological Society