EARLY EOCENE MACROFLORA FROM THE RED HOT TRUCK STOP MERIDIAN, MISSISSIPPI, USA

The U.S. Gulf Coast has an extensive but poorly dated paleobotanical record. A fossil locality behind the former Red Hot Truck Stop in Meridian, Mississippi, is well known for its unusually rich biota of late Paleocene and early Eocene mammals, fish, snakes, mollusks, and plants. The latter include palynomorphs, fruits, and leaves, which are found in the basal Bashi Formation and studied here. Though generally not well preserved, the Red Hot leaf flora is significant because it is reliably dated to the first 1.6 million years of the Eocene; in contrast, nearly all other Eocene Gulf Coast macrofloras are middle Eocene or uncertain in age. We recognize 18 leaf morphotypes, including representatives of Lygodium kaulfussi (a climbing fern), Lauraceae (laurel family), Arecaceae (palms), Myrtaceae (guava family), Fabaceae (legumes), Platycarya (Juglandaceae, walnut family), a new species of Ochnaceae (ochna family), and Rhus (Anacardiaceae, sumac family), all consistent with tropical to subtropical climates. The Platycarya specimen is the first macrofossil of this Eocene index taxon from the Eastern USA and corroborates pollen occurrences from the same strata. The Ochnaceae leaves appear to be the only reliable fossil representatives of this distinctly tropical group with 40 genera and 600 species today. The other recognizable genera and families are present at, or near, this time in the well-dated sequences of the Rocky Mountain region, indicating their wide North American distribution. The Red Hot flora shows the potential to build a well-dated record of Paleogene floras on the Gulf Coast, improving understanding of plant migration and evolution.