Abstract Detail

Paleobotany

Baghai-Riding, Nina [1], Axsmith, Brian [2], Phillips, George [3], Starnes, James [4].

Paleoclimate and taphonomic implications of a palynological sample from the Late Oligocene of Wayne County, Mississippi.

The Jones Branch interval of the Catahoula Formation (late Oligocene, 25 - 23.8 Ma) outcrops in Wayne County, southeastern Mississippi. Recently, this site has yielded an assortment of terrestrial and marine-adapted vertebrate taxa including rodents, artiodactyls, perissodactyls, carnivores, sirenians, reptiles, amphibians, teleostean fish, and more. A dark, carbonaceous clay that yields abundant plant megafossils lies directly above the vertebrate layer. Endocarps of Nyssa and leaf compressions of Lauraceae, palms, and other undescribed morphotypes with entire or toothed margins suggest a warm-temperate to subtropical paleoclimate. One random palynological sample was acquired from the plant megafossil layer. Preservation of palynomorphs vary from exceptionally well-preserved to being corroded and difficult to discern. Some palynomorphs probably were acquired from long-distance airborne transport from an upland, coastal forest; others are characteristic of plants growing along local river banks; and several palynomorphs are indicative of a marine influence. In a 300-point count, angiosperms represented 35.3%, conifers 0.03%, pteridophyte spores 38.6%, and dinoflagellates cysts, acritarchs, inner linings of foraminifera, and freshwater algal forms 23.1%. Dominant pollen types include Carya, Ilex, Juglans, Onagraceae, Pinus, Quercus, Ulmus, and Salix. Common sporomorphs are assignable to Cyatheaceae, Polypodiaceae, and Schizaeaceae. Overall, the palynological assemblage is considerably different from the regional vegetation implied by the megaflora. The palynomorphs, however, support a tidal influence, estuarine paleoenvironmental setting that is conveyed by the vertebrates.

1 - Delta State University, Department Of Biological SciencesSciences, Walters Hall Room 116A, Cleveland, MS, 38733, United States
2 - Biology Department, 5871 USA Drive North, Room 124, Mobile, AL, 36688, United States
3 - Mississippi Museum of Natural Science, Paleontology, 2148 Riverside Drive, Jackson, MS, 39202, USA
4 - Mississippi Department of Environmental Quality, Office of Geology, P.O. Box 2279, Jackson, MS, 39225

Keywords:
palynomorph
late Oligocene
megafossil.

Presentation Type: Poster
Session: P, Paleobotany posters
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPB004
Abstract ID:981
Candidate for Awards:None