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Full-Text Articles in Biodiversity

Risk-Prone And Risk-Averse Foraging Strategies Enable Niche Partitioning By Two Diurnal Orb-Weaving Spider Species, Mitchell D. Long May 2022

Risk-Prone And Risk-Averse Foraging Strategies Enable Niche Partitioning By Two Diurnal Orb-Weaving Spider Species, Mitchell D. Long

Electronic Theses and Dissertations

Niche partitioning is a major component in understanding community ecology and how ecologically similar species coexist. Temporal and spatial partitioning and differences in foraging strategy, including sensitivity to risk (variance), likely contribute to partitioning as well. Here, we approach this partitioning with fine resolution to investigate differences in overall strategy between two species of diurnal, orb-weaving spiders, Verrucosa arenata and Micrathena gracilis (Araneae: Araneidae), that share similar spatial positioning, temporal foraging window, and prey. Through field observation, we found that V. arenata individuals appear to increase spatial and temporal sampling to compensate for an overall risk-prone strategy that depends on …


Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim May 2017

Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim

Electronic Theses and Dissertations

Despite being separated by millions of years of evolution, black bears (Ursus americanus) and brown bears (Ursus arctos) can be difficult to distinguish based on skeletal and dental material alone. Complicating matters, some Late Pleistocene U. americanus are significantly larger in size than their modern relatives, obscuring the identification of the two bears. In the past, fossil bears have been identified based on differences in dental morphology or size. This study used geometric morphometrics to look at overall differences in cranial shape and used step-wise discriminant analysis to identify specific characters that distinguish cranial morphology between …


A Systematic Review Of The Soricimorph Eulipotyphla (Soricidae: Mammalia) From The Gray Fossil Site (Hemphillian), Tennessee, Joshua Doby May 2015

A Systematic Review Of The Soricimorph Eulipotyphla (Soricidae: Mammalia) From The Gray Fossil Site (Hemphillian), Tennessee, Joshua Doby

Electronic Theses and Dissertations

Due in part to the incompleteness of the Cenozoic fossil record in the eastern U.S., the evolution and immigration of shrews (Soricidae) is not well understood. A rich soricid fauna from the Gray Fossil Site (GFS), Washington County, TN, has enabled many new inferences to be made. There are 7 new species in 6 genera: Paenelimnoecus, “Blarinella”, Petenyia, Tregosorex, Crusafontina, and Gen et sp. nov. GFS species of the genera Paenelimnoecus, “Blarinella”, and Petenyia are the first occurrence of each genus in the New World. Tregosorex, Crusafontina, and the N.A. taxon Limnoecus all have their latest documented occurrence at the …


Inter-And Intra-Population Variability Across The Transcriptome Of Lake Baikal’S Endemic Copepod With Ramifications For Adapting To Climate Change, Larry L. Bowman Jr May 2014

Inter-And Intra-Population Variability Across The Transcriptome Of Lake Baikal’S Endemic Copepod With Ramifications For Adapting To Climate Change, Larry L. Bowman Jr

Electronic Theses and Dissertations

The future of Lake Baikal’s biodiversity is uncertain in response to climate change. Unlike its diverse benthos, Lake Baikal’s zooplankton is species poor, with up to 96% of its biomass being composed of a single Calanoid copepod species, Epischura baikalensis. This study characterizes the genetic differentiation and differential gene expression of E. baikalensis. Using partial-transcriptome sequences obtained by 454 Rosche and Illumina sequencing technologies, the genetic differentiation at inferred single nucleotide polymorphism (SNP) sites and differential gene expression in populations sampled from various parts of the lake were analyzed. The functional genomics of genes showed significant differential …


A Glyptosaurine Lizard From The Eocene (Late Uintan) Of San Diego, California, And Implications For Glyptosaurine Evolution And Biogeography, David Moscato Aug 2013

A Glyptosaurine Lizard From The Eocene (Late Uintan) Of San Diego, California, And Implications For Glyptosaurine Evolution And Biogeography, David Moscato

Electronic Theses and Dissertations

Glyptosaurinae is an extinct subfamily of lizards of the family Anguidae. Glyptosaurine lizards are known exclusively from the Paleogene of North America and Eurasia, reaching their peak of diversity and distribution in the Eocene. In North America these lizards are largely restricted to the intermontane basins along the Rocky Mountain range, with only sparse, indeterminately-identified skeletal elements known from outside of this region. Glyptosaurine lizards are split into two tribes: the monophyletic Glyptosaurini and paraphyletic “Melanosaurini”. Within Glyptosaurini, the most common and widespread genus is Glyptosaurus. In this study I describe a new specimen assignable to G. sylvestris, …