Abstract Detail

Paleobotany

Stults, Debra [1], Axsmith, Brian J. [2].

Newly Identified plant fossils from the Miocene Brandywine flora of Maryland, U.S.A.

The depositional environment of the Miocene Brandywine Formation of the Mid-Atlantic Coastal Plain of Maryland near Washington, D.C has been characterized as a braided stream system, similar to that occurring in the modern-day Salisbury Embayment of the same region. Previously identified plant fossils consisting of mostly endemic North American taxa, along with several exotics and one extinct genus suggest a Late Miocene age designation (approximately 10 to 6 Ma). Forty-nine plant taxa were identified from the original 1990 study based on pollen (23 taxa), leaves (23 taxa) and fruit (16 taxa), wherein some taxa were represented by multiple organs. These identifications suggest a transitional/upland depositional environment. Subsequent work in our lab based mainly on continued identification of mesofossils extracted from the Brandywine matrix has produced several new records including stems of Equisetum sp., Cyperaceae fruits and seeds (Scirpus and Carex), a Taxus seed (Taxaceae), Lithospermum cf. arvense (Boraginaceae) seeds, Cleome (Cleomaceae) seeds, Portulaca (Portulacaceae) and undetermined Caryophyllaceae sp. seeds, a Ranunculus (Ranunculaceae) seed, lauraceous receptacles (similar to those of Persea and Sassafras), Maclura fruits, and Carpinus (Betulaceae) nutlets. Interestingly, the small Brandywine Macurla fruit is more similar to southeastern Asian species than to the large, endemic Maclura pomifera. Our previous quantitative climatic study (2011) indicated that the Brandywine flora grew under warmer conditions than those of the modern Mid-Atlantic Coastal Plain. Ongoing research is focused on additional identifications of this rich flora, and in determining how the newly identified taxa will affect paleoclimate estimates.

1 - 27640 Rigsby Road, Daphne, AL, 36526, USA
2 - University Of South Alabama, Biology Department, 5871 USA Drive North, Room 124, MOBILE, AL, 36688-0002, USA

Keywords:
Brandywine Formation
Late Miocene
Mid-Atlantic Coastal Plain.

Presentation Type: Poster
Session: P, Paleobotany posters
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
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:292
Candidate for Awards:None