DeVore, Melanie L. , Sullivan, Amanda L. , Pigg, Kathleen B. .
Monocots from the Late Paleocene of North Dakota, U. S. A..
Monocot remains, including rhizomes with attached roots, tubers and leaf bases, large petioles, foliar buds with sheathing leaves, several types of leaf laminae, seeds and embryos are described from sites within the Late Paleocene (Tiffanian) Almont and Beicegel Creek localities of central and western North Dakota, USA. We believe these remains represent at least two types of plants: an aquatic plant with possible affinities with Alismatales and a second form related to the Zingiberales. Organs of the aquatic plant include rhizomes with attached roots, tubers, petioles and leaf blades, and foliar buds with sheathing leaves. Rhizomes can bear clusters of tubers and also produce leaves with long petioles and flattened blades distally. Large roots have a pattern of small cuboidal cells covering their surface and produce numerous lateral roots. Masses of smaller roots are also found. The leaf lamina has several prominent parallel large veins that produce densely spaced secondary veins at right angles that are similar to both leaves referred to Zingiberopsis by Hickey and to extant taxa in the Alismatales, including the genus Sagittaria. This aquatic plant is similar to the ”unidentified sheathing structures”from the Late Paleocene Joffre Bridge flora of Alberta and to the "unidentified monocotyledon rhizome" of the Golden Valley flora of North Dakota, demonstrating the occurrence of this aquatic plant at several different Paleogene sites. The second monocot at the Almont and Beicegel Creek sites is represented by seeds and embryos ("clavate structures") referable to the genus Spirematospermum, a zingiberalean taxon known from the Paleocene of Greenland, as well as numerous sites in the Late Cretaceous and Tertiary of Europe and eastern North America.
1 - Georgia College & State University, Biological & Environmental Sciences, 135 Herty Hall, Campus Box 81, Milledgeville, Georgia, 31061, USA
2 - Arizona State University, School of Life Sciences, PO Box 874501, Tempe, Arizona, 85287-4501, USA
Presentation Type: Paper
Location: Maybird (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 11:15 AM