The occurrences of Staphylea L. (Staphyleaceae) fossils have been abundantly documented from the Cenozoic of Eurasia, but none has been confirmed from North America to date. In this study, we describe Staphylealevisemia sp. nov. on the basis of seed remains from the latest Miocene to earliest Pliocene of northeastern Tennessee, southeastern USA. The seeds are characterized by a smoothly inflated body, a large hilar scar perforated by several vascular traces and bordered by a distinctive lip-like rim, a cuticle coating the seed coat interior, and seed coat section containing weakly developed tiny lumina. According to the paleogeographic distribution of the genus, it is hypothesized that Staphylea originated from western Eurasia no later than the late Oligocene, and arrived in eastern North America no later than the late Neogene, most possibly through the North Atlantic land bridges like many other seed plants.

This Ph.D. dissertation integrates stable isotope and trace element geochemistry in modern and fossil gastropod shells to study low-latitude marine paleoenvironments. First, stable isotopes (delta18O and delta13C) and Sr/Ca ratios are used to examine low-latitude temperature and salinity variations recorded in Plio-Pleistocene (3.5-1.6 Ma) fossils from western Florida during periods of high-latitude warming and "global" cooling. The middle Pliocene Pinecrest Beds (Units 7 and 4) and the overlaying Plio-Pleistocene Caloosahatchee Formation generate significantly different delta18O-derived paleotemperatures but identical Sr/Ca ratios. High delta18O values, together with low delta13C values and brackish fauna, indicate that Unit 4 was deposited in a lagoonal environment similar to modern Florida Bay. In contrast, relatively low delta18O and high delta13C values in Unit 7 and Caloosahatchee Formation represent deposition in an open-marine environment. The observed Unit 7 and Caloosahatchee paleotemperatures are inconsistent with middle Pliocene warming event, but consistent with the Plio-Pleistocene cooling trend. To quantify modern upwelling and freshening signals and contrast these signals between the tropical eastern Pacific (TEP) and southwestern Caribbean (SWC), methodologies are developed for reconstructing seasonal upwelling and freshening patterns from modern tropical gastropod shells from Panama using: 1) paired oxygen and carbon isotopic profiles and delta18O-delta13C (delta-delta) correlations, and 2) deviation from baseline delta18O values that represent conditions free of seasonal upwelling or freshening influences. Shell delta18O values normalized to the baseline faithfully record modern conditions of little or no upwelling in SWC and Gulf of Chiriqui, and strong upwelling in the Gulf of Panama, as well as strong freshwater input in most areas. The baseline and delta-delta methods are applied to identify and quantify changes in upwelling and freshening in the Neogene TEP and SWC seawaters associated with the final closure of Central American Isthmus. The records reveal significant upwelling in late Miocene SWC and mid Pliocene TEP waters, strong freshening in SWC waters from 5.7-2.2 Ma, and minimal seasonal upwelling and/or freshening variations in Plio-Pleistocene SWC waters. The reconstructed paleotemperatures agree with the global cooling trend through the late Miocene, but lack evidence for middle Pliocene warming or late Neogene global cooling.

This study focuses on morphometric and systematic analyses of the fossil Vitis seeds, recovered from the Gray Fossil Site (7-4.5. Ma, latest Miocene-earliest Pliocene), northeastern Tennessee, U.S.A. A multivariate analysis based on eleven measured characters from 76 complete fossil seeds recognizes three morphotaxa. Further comparisons with both selected modern and fossil vitaceous specimens confirm that these morphotaxa represent three new species, viz. Vitis grayensis sp. nov., Vitis lanatoides sp. nov., and Vitis latisulcata sp. nov. Furthermore, the close resemblance of the first two fossil grapes (V. grayensis and V. lanatoides) with two East Asian Vitis species provides further support concerning a strong eastern Asian aspect of the Gray fossil biota in the late Neogene southeastern North America, as previously evidenced by both animals (e.g. Pristinailurus bristoli [red panda]) and other plants (e.g. Sinomenium and Sargentodoxa).

This study focuses on the morphometric and systematic studies of fossil vitaceous seeds recently recovered from the Gray Fossil Site (7-4.5 Ma, latest Miocene-earliest Pliocene) northeastern Tennessee. Morphologically, all fossil seeds correspond to the extant subgenus Vitis (genus Vitis) of the Vitaceae based on the smooth dorsal surface with a centrally positioned chalaza connected with a conspicuous chalaza-apex groove and short linear ventral infolds that are slightly diverged apically. A multivariate analysis based on 11 measured characters from 76 complete seeds identified three types of seeds, each representing a distinct morphotaxon. Based on comparison with modern and fossil vitaceous specimens, three new species were recognized: Vitis grayana sp. nov., Vitis lanatoides sp. nov., and Vitis latisulcata sp.nov. The close resemblance between the first two fossil grapes (Vitis grayana and Vitis lanatoides) with extant eastern Asian Vitis provides further evidence that the eastern Asian floristic elements existing in the southeastern North American flora continued to as late as late Neogene.