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Abstract Detail


Jud, Nathan [1], Burch, Claire [2], Serbet, Rudolph [3].

Late Pennsylvanian (Missourian) plants from the Dennis Formation in Clay County, Missouri.

During the Late Paleozoic Ice Age (Carboniferous-Permian), a long-term drying trend superimposed on short-term glacial-interglacial cycles led to the replacement of tropical wetland rainforests (coal forests) by more xeromorphic floras. The extirpation of Lycospora-producing lepidodendrid trees from North America at the Desmoinesian-Missourian boundary (~306 million years ago) marks an important shift in tropical wetland ecosystems. Here, we share a preliminary report of a plant fossil assemblage from the early-mid Missourian rocks of the North American midcontinent. The fossils are preserved in a light gray carbonaceous shale from the Dennis Formation (Forest City Basin) in Clay County, Missouri, USA. The assemblage is dominated by Neuropteris lindhali White, a species with fronds that are is at least twice pinnate and bear small (<100 mm2) pinnules with revolute margins. The assemblage also includes characteristic cyclopterid pinnules, larger neuropterid pinnules up to ~1100 mm2, strap-shaped Cordaites leaves at least 8 cm long with prominent parallel veins, and a fern-like plant with minute (~4 mm2) pecopterid pinnules and obscure venation. Both medullosan gymnosperms and cordaitaleans occur in wetland rainforest floras as well as seasonally dry tropical floras throughout the Pennsylvanian. Based on leaf area, the revolute margins of N. lindhali, and lithologic context (absence of any associated coal), we hypothesize that these plants tolerated seasonally dry conditions that prevailed in the tropical lowlands of the midcontinent region during the Missourian.

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1 - William Jewell College, Biology, 300 College Hill, Liberty, MO, 64068, United States
2 - William Jewell College, Department of Biology, 500 College Hill, Liberty, MO, 64068, USA
3 - University Of Kansas, Division Of Paleobotany, Biodiversity Institute, 1200 Sunnyside Avenue, Lawrence, KS, 66045, United States


Presentation Type: Oral Paper
Session: PL6, Paleobotany: Paleozoic/Mesozoic Paleobotany
Location: /
Date: Thursday, July 22nd, 2021
Time: 10:00 AM(EDT)
Number: PL6001
Abstract ID:986
Candidate for Awards:None

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