Graduation date: 1953

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During the Austral Spring of 2007-2008 the ANtarctic geological DRILLing program (ANDRILL) recovered a 1,138 meter long sediment core AND-2A from the western side of the Victoria Land Basin for the Southern McMurdo Sound Project. The main goal of the project is to help establish a Neogene (~24 to 1.6 Mya) ice volume and climate record of Antarctica. This study focuses on the foraminifera record of AND-2A for paleoenvironmental and biostratigraphic purposes.AND-2A is unique in that it contains a Middle Miocene record (~17 to ~11 Mya) that includes the Middle Miocene transition of warm climatic conditions favoring polythermal ice sheets to major cooling into polar conditions resulting in the quasi-permanent formation of the East Antarctic Ice Sheet. This Middle Miocene transition has not been previously recovered from the Antarctic continental margin.The foraminifer record is not abundant; however, three assemblage zones are identified throughout AND-2A. Calcareous benthic taxa dominate every assemblage, as well as displaying similarities between modern shallow shelf assemblages around Antarctica and assemblages from previous drilling projects in the Ross Sea sector. The foraminifera record displays a dynamic environmental record and is supported by both the sedimentologic and other paleontologic findings.

The middle Miocene thermal maximum (~16 Ma) was a period of global climate unusually warm and wet for the Neogene and is of interest as a paleo-analog for future climate change from anthropogenic global warming. In Australia, paleosols of the Oligocene-Miocene Etadunna and Pliocene Tirari Formations formed in arid palaeoclimates and include pedogenic gypsum. The Middle Miocene paleosol has shallow calcareous nodules and stout root traces suggesting vegetation like dry woodland. Comparable mallee vegetation now grows no closer than 1200 km to the southwest, so middle Miocene warm-wet climate enabled range extension of mallee and woody thickening of plants in the Australia outback. There is no evidence in the outback of middle Miocene rain forest, which may have expanded its range to form kaolinitic Ultisols near Sydney, Mudgee, and Gulgong, in New South Wales. Nor is there evidence so far inland of swamp woodlands and heaths like those producing brown coals in the Latrobe Valley, Victoria. In Argentina, the Santa Cruz Formation, in addition to its rich fossil vertebrate assemblages, contains a similar paleosol record of middle Miocene climate change. The early Miocene in the Santa Cruz Formation is characterized by a thick sequence of weakly to strongly developed grassland paleosols (Orthents and Ustolls) as well as paleosols with root traces and profile forms of open shrubland vegetation (Cambid). The middle Miocene thermal maximum is characterized by paleosols (Udepts, Udalfs) developed under open woodland-shrubland vegetation, during a period of climatic warmth and humidity. The late middle Miocene is characterized by a greater diversity of pedotypes, all suggestive of an arid and cooler environment (Argids, Cambids, and Ustepts). Middle Miocene soil maps compiled for this study show extension of tropical soils (Oxisols, Ultisols) into northern and southern mid-latitudes, accompanied by thermophilic flora and fauna. Peats, lignites, and Histosols of wetlands are also more abundant at higher latitudes, especially in the northern hemisphere, during the middle Miocene. The expansion of such soils is an expected result of greater precipitation associated with higher water vapor content of a warmer atmosphere during the Middle Miocene. This dissertation includes previously published co-authored material in chapter II.

The Paşalar fauna is found to include four suoid species including two listriodont pigs, Listriodon ef. splendens and Listriodon sp. nov., a tetraconodont, Conohyus simorrensis (sensu lato) and a peccary, Taucanamo inonuensis. This assemblage of folivores and "omnivores" presumably veflects the presence of relatively lush vegetation in the area. The cooccurrence of a derived sublophodont listriodont, Listriodon sp. nov., of roughly similar evolutionary grade to the late early Miocene European species Listriodon lockharti (from MN 4b and 5 localities of Europe) with the lophodont form Listriodon ef. splendens (MN 6-MN 9 localities of Europe suggests that the Paşalar fauna is referrable to MN 6, ea. 15 Ma, or possibly somewhat younger. While the Paşalar suoid assemblage shows broad Eurasian affinities, Listriodon sp. nov. and Taucanamo inonuensis provide evidence for a certain degree of endemism. We hypothesize here that this endemism developed after the late Burdigalian marine regression (ca. 17 Ma, and taken here as being chronologically equivalent to MN4b and lower MN 5), which promoted active Eurasian and African faunal exchanges.

An abundant fossil record of the snake clade Scolecophidia exists in Europe; however, the minute snake is noticeably absent in reports about the North American Paleogene and Neogene. Presented here are four localities from Florida, USA, that contain scolecophidian remains older than the Pleistocene: Thomas Farm (late Early Miocene, Hemingfordian Land Mammal Age, LMA), Live Oak (Oligocene-Miocene transition, latest Arikareean LMA), White Springs 3B (late Arikareean LMA), and Brooksville 2 (Late Oligocene, middle Arikareean LMA). These remains extend their known existence by about 26. m.y. and are now the oldest reported scolecophidian remains in North America. Molecular evidence on extant scolecophidians concludes that these tiny snakes have a Gondwanan origin. Interestingly, the oldest record of a scolecophidian is from Europe (Belgium) and dates back to the middle Paleocene (MP 1-5). The earliest African record of the snake clade comes from the Paleocene-Eocene boundary in Morocco. The clade is apparently absent from Europe and Middle East deposits dating from the latest Eocene through to the latest Oligocene (MP 19-30) and to the Early Miocene (MN 4). A portion of this time is known as the booid 'Dark Period' which represents an apparent response to global aridization and cooling. Scolecophidians appear to re-emerge into the southern Eurasian record in the Early Miocene (MN 4) and become widely dispersed throughout Europe and Middle East. The fossil record of these minute snakes is largely absent in southern Asia and South America. It is possible that the current lack of a decent fossil scolecophidian record outside of Europe and Middle East is due mainly to a bias in the methodology to recover fossils; wet sieving sediments through. < 1.0. mm mesh is needed to recover the minuscule vertebrae.

An abundant fossil record of the snake clade Scolecophidia exists in Europe; however, the minute snake is noticeably absent in reports about the North American Paleogene and Neogene. Presented here are four localities from Florida, USA, that contain scolecophidian remains older than the Pleistocene: Thomas Farm (late Early Miocene, Hemingfordian Land Mammal Age, LMA), Live Oak (Oligocene-Miocene transition, latest Arikareean LMA), White Springs 3B (late Arikareean LMA), and Brooksville 2 (Late Oligocene, middle Arikareean LMA). These remains extend their known existence by about 26. m.y. and are now the oldest reported scolecophidian remains in North America. Molecular evidence on extant scolecophidians concludes that these tiny snakes have a Gondwanan origin. Interestingly, the oldest record of a scolecophidian is from Europe (Belgium) and dates back to the middle Paleocene (MP 1-5). The earliest African record of the snake clade comes from the Paleocene-Eocene boundary in Morocco. The clade is apparently absent from Europe and Middle East deposits dating from the latest Eocene through to the latest Oligocene (MP 19-30) and to the Early Miocene (MN 4). A portion of this time is known as the booid 'Dark Period' which represents an apparent response to global aridization and cooling. Scolecophidians appear to re-emerge into the southern Eurasian record in the Early Miocene (MN 4) and become widely dispersed throughout Europe and Middle East. The fossil record of these minute snakes is largely absent in southern Asia and South America. It is possible that the current lack of a decent fossil scolecophidian record outside of Europe and Middle East is due mainly to a bias in the methodology to recover fossils; wet sieving sediments through. < 1.0. mm mesh is needed to recover the minuscule vertebrae.

Ochotonids (pikas) are an ancient group of mammals originating in the Oligocene of Asia and flourishing in the Miocene of the Old World. During the Pliocene they reduced both their diversity and abundance, Only the Pleistocene genus Ochotona survived to the present. Their current geographic diversity is concentrated in Asia, where 28 species exist today. Outside of Asia, ochotonids are represented by one living species in Europe and two living species in North America. There were likely three main immigrations to North America since the Miocene: (1) at the beginning of the Miocene represented by the appearance of Oreolagus; (2) at the Miocene- Pliocene boundary represented by the appearance of Ochotona spanglei; and (3) during the Early Pleistocene with the appearance of Ochotona whartoni, and small pikas close to the "Ochotona pusilla group". Extant, endemic North American species appear in the Pleistocene.