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Full-Text Articles in Physical Sciences and Mathematics
Vitis Seeds (Vitaceae) From The Late Neogene Gray Fossil Site, Northeastern Tennessee, Usa., Fade Gong
Vitis Seeds (Vitaceae) From The Late Neogene Gray Fossil Site, Northeastern Tennessee, Usa., Fade Gong
Electronic Theses and Dissertations
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 …
A Phylogenetic Analysis Of Species Relationships In Hemlocks, The Genus Tsuga (Pinaceae)., Jordan David Baker
A Phylogenetic Analysis Of Species Relationships In Hemlocks, The Genus Tsuga (Pinaceae)., Jordan David Baker
Electronic Theses and Dissertations
The genus Tsuga is comprised of eight extant species found in North America and East Asia and four species represented by fossils from Europe and Japan. This study presents the first phylogenetic analysis based on structural, biochemical, and molecular sequence data. Characters obtained from published and unpublished literature were combined with new morphological characters from seeds, seedlings, and leaf cuticle material. Results from parsimony analyses of these characters differed from the published molecular based phylogeny. The non-molecular based phylogeny resolves two separate clades, a North American and an Asian, but did not group the western North American species, as in …
Salamanders Of The Mio-Pliocene Gray Fossil Site, Washington County, Tennessee., Grant Stanley Boardman
Salamanders Of The Mio-Pliocene Gray Fossil Site, Washington County, Tennessee., Grant Stanley Boardman
Electronic Theses and Dissertations
Screening efforts at the Gray Fossil Site, Washington County, Tennessee, have yielded a unique and diverse salamander fauna for the southern Appalachian Mio-Pliocene; including at least five taxa from three modern families (Ambystomatidae, Plethodontidae, and Salamandridae) supporting the woodland-pond interpretation of the site. All specimens represent the earliest record of their respective families in the Appalachian Mountains; with the Notophthalmus sp. vertebrae being the only Mio-Pliocene skeletal fossil known for the family Salamandridae in North America. Three types of plethodontid salamander are present, with one type representing the earliest known desmognathine. The desmognathine fossils lend credence to the 'Appalachian' origin …