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Full-Text Articles in Paleontology

Isotopic Ecology Of Bison And Bootherium At Big Bone Lick, Kentucky, Frances Stephenson Dec 2023

Isotopic Ecology Of Bison And Bootherium At Big Bone Lick, Kentucky, Frances Stephenson

Electronic Theses and Dissertations

Big Bone Lick (BBL) is a late Pleistocene and Holocene fossil locality in the Ohio River valley of Kentucky. This study utilized stable isotopes (δ13C, δ18O, and 87Sr/86Sr) in tooth enamel to reconstruct mobility and diet in Bison, as well as diet in Bootherium bombifrons. Isotopic results from seven Bison and two B. bombifrons are reported. Results suggest Pleistocene Bison and Bootherium occupied different dietary niches. Although both had C3-dominated diets, Bison occupied more open environments than B. bombifrons. Two bison from the late Holocene deposit had diets that consisted …


Early Pliocene Mice And Rats From The Gray Fossil Site Of Eastern Tennessee: Implications For The Evolution Of Cricetidae And Understanding Of The Past Ecosystem, Ziqi Xu Dec 2023

Early Pliocene Mice And Rats From The Gray Fossil Site Of Eastern Tennessee: Implications For The Evolution Of Cricetidae And Understanding Of The Past Ecosystem, Ziqi Xu

Electronic Theses and Dissertations

Cricetidae ranks as the second-most species-rich and abundant mammalian family, with limited studies on eastern North American records prior to the Pleistocene. While cricetids has been previously noted at the early Pliocene Gray Fossil Site (GFS), this study provides a detailed description of eight taxa: Postcopemys (two species), Symmetrodontomys, Oryzomyini, Peromyscus, Neotoma, Neotomodon, and Xenomys. Postcopemys is the most common cricetid taxon at GFS, followed by Peromyscus and Neotoma. These records expand the stratigraphic and geographic range of multiple genera. Distinctive morphological features of GFS taxa suggest presence of several new species. The …


Geometric Morphometric Analysis Of Modern Viperid Vertebrae Facilitates Identification Of Fossil Specimens, Lance D. Jessee Aug 2023

Geometric Morphometric Analysis Of Modern Viperid Vertebrae Facilitates Identification Of Fossil Specimens, Lance D. Jessee

Electronic Theses and Dissertations

Snake vertebrae are common in the fossil record, whereas cranial remains are generally fragile and rare. Consequently, vertebrae are the most commonly studied fossil element of snakes. However, identification of snake vertebrae can be problematic due to extensive variation. This study utilizes 2-D geometric morphometrics and canonical variates analysis to 1) reveal variation between genera and species and 2) classify vertebrae of modern and fossil eastern North American Agkistrodon and Crotalus. The results show that vertebrae of Agkistrodon and Crotalus can reliably be classified to genus and species using these methods. Based on the statistical analyses, four of the …


Age And Paleontology Of The Turin Pit Locality, Monona County, Iowa, Samantha Wright Aug 2023

Age And Paleontology Of The Turin Pit Locality, Monona County, Iowa, Samantha Wright

Electronic Theses and Dissertations

The Turin Pit locality (Monona county, Iowa) has been known to paleontologists since 1908, yet the age of the fauna has been unclear. Early paleontologists considered Turin Pit to date to a pre-Illinoian interglacial (the “Aftonian).” Subsequent researchers suggested it dated to the last glaciation. This study provides a partial list of mammals in the Turin Pit fauna, and together with stratigraphic information, uses the known age ranges of taxa to estimate an age for the assemblage. The presence of Mammuthus, Aenocyon, and Castoroides combined with a magnetically-reversed till located stratigraphically above fossil-bearing deposits, suggest the Turin Pit …


Fossil Mammals From Hickory Tree Cave, Sullivan County, Tennessee, Alexis Rivera Dec 2022

Fossil Mammals From Hickory Tree Cave, Sullivan County, Tennessee, Alexis Rivera

Electronic Theses and Dissertations

Hickory Tree Cave, also known as Big Spring Cave, is located in the southern Appalachians and is known for fossils that are considered to be Quaternary in age. Fossil mammals were identified and assigned to the lowest taxonomical level possible. Most remains are fragmented or digested and it seems likely that various taphonomic processes are responsible for the resulting assemblage. The site lacks the extreme boreal component of Pleistocene cave faunas in the region (e.g. Baker Bluff Cave), with most reported taxa inhabiting Appalachian deciduous forest environments in North America today. While the presence of tapir (Tapirus sp.) …


Community Structure Analysis Of Turtles With Application To The Early Pliocene Gray Fossil Site, Julian Conley Aug 2022

Community Structure Analysis Of Turtles With Application To The Early Pliocene Gray Fossil Site, Julian Conley

Electronic Theses and Dissertations

Turtles are important components of ecosystems around the world, with diverse ecological niches and adaptations. However, there are few detailed studies of how turtle community structure reflects local environments. This project applied techniques of community structure analysis to sites across the United States to infer past ecosystem and environmental conditions of the early Pliocene Gray Fossil Site (GFS) in northeastern Tennessee based on the ancient turtle community. Results indicate extant turtle community structure closely reflects environmental conditions, and that ancient turtle communities can be used to infer climate and habitat conditions of past ecosystems. Application to the GFS turtle community …


The Paleoecology Of High-Elevation Bison In The Greater Yellowstone Ecosystem And Implications For Modern Bison Conservation, Darian Bouvier Aug 2022

The Paleoecology Of High-Elevation Bison In The Greater Yellowstone Ecosystem And Implications For Modern Bison Conservation, Darian Bouvier

Electronic Theses and Dissertations

The national mammal of the United States, the American Bison (Bison bison) was once nearly extinct. Populations have recovered to the degree that thousands roam the Great Plains today. Due to their large numbers and body size, this species has an oversized impact on the ecological communities where it lives and is considered a keystone herbivore in modern North American grasslands. This study explores the detailed, seasonally resolved, paleoecology of seven bison from the Greater Yellowstone Ecosystem during the Late Holocene through stable isotope analyses and species niche modeling. Isotopic analyses of δ13C, δ15N, …


An Evaluation Of Castor Californicus And Implications For The Evolution And Distribution Of The Genus Castor (Rodentia: Castoridae) In North America, Kelly Lubbers Aug 2022

An Evaluation Of Castor Californicus And Implications For The Evolution And Distribution Of The Genus Castor (Rodentia: Castoridae) In North America, Kelly Lubbers

Electronic Theses and Dissertations

The genus Castor is represented in Eurasia by Castor fiber, North America by C. canadensis, and has been in North America since the late Miocene. This study aims to assess whether morphology of Miocene-Pliocene C. californicus and extant C. canadensis are distinctly different. Specimens of Castor were compared using geometric morphometrics on cranial material and linear measurements of postcranial material. Species occurrence data were compared with past and future climate data to assess Castor distribution in North America through time. Results show that C. canadensis is highly variable in both cranial and postcranial morphology and C. californicus falls …


Community Structure Analysis Of Mammals Found At The Gray Fossil Site, Tn, Sarah Clark May 2022

Community Structure Analysis Of Mammals Found At The Gray Fossil Site, Tn, Sarah Clark

Electronic Theses and Dissertations

The early Pliocene Gray Fossil Site (GFS) is a biodiverse site with a unique faunal assemblage that represents one of few sites of its age in eastern North America. A community structure analysis of the mammals at GFS was done to characterize species and better understand the paleoenvironment. Data and was gathered from twenty modern communities and five late Neogene sites to compare with GFS. Species from these 26 sites were categorized by body size, locomotor mode, cheek tooth crown height, and diet to characterize niches occupied. Descriptive statistics contrasted proportions of species within categories across communities. Discriminant function analyses …


Distinguishing Mustela From Neogale (Mustelidae) Through Both A Qualitative And Quantitative Analysis Of Skull And Tooth Morphology, Ronald W. Peery Dec 2021

Distinguishing Mustela From Neogale (Mustelidae) Through Both A Qualitative And Quantitative Analysis Of Skull And Tooth Morphology, Ronald W. Peery

Electronic Theses and Dissertations

Weasels and mink (Mustela and Neogale) can be difficult to distinguish osteologically due to similarities in morphology, thus suggesting the need for an accurate tool in distinguishing among taxa. This study utilized a combination of character state and stepwise discriminant function (DFA) analyses to examine potential distinguishing features of skull and tooth morphology. Measurements and ratios were collected from all 18 extant musteline species, as well as the extinct Neovison macrodon, Mustela rexroadensis, Mustela meltoni, Mustela gazini, and Mustela jacksoni. Unidentified musteline specimens from the Gray Fossil Site were also included. Results of …


Spatial Analyses Of Gray Fossil Site Vertebrate Remains: Implications For Depositional Setting And Site Formation Processes, David Carney Aug 2021

Spatial Analyses Of Gray Fossil Site Vertebrate Remains: Implications For Depositional Setting And Site Formation Processes, David Carney

Electronic Theses and Dissertations

This project uses exploratory 3D geospatial analyses to assess the taphonomy of the Gray Fossil Site (GFS). During the Pliocene, the GFS was a forested, inundated sinkhole that accumulated biological materials between 4.9-4.5 mya. This deposit contains fossils exhibiting different preservation modes: from low energy lacustrine settings to high energy colluvial deposits. All macro-paleontological materials have been mapped in situ using survey-grade instrumentation. Vertebrate skeletal material from the site is well-preserved, but the degree of skeletal articulation varies spatially within the deposit. This analysis uses geographic information systems (GIS) to analyze the distribution of mapped specimens at different spatial scales. …


Isotopic Analysis And Mobility Mapping Of Mammuthus Columbi From The Mammoth Site In South Dakota, Matthew Harrington Aug 2021

Isotopic Analysis And Mobility Mapping Of Mammuthus Columbi From The Mammoth Site In South Dakota, Matthew Harrington

Electronic Theses and Dissertations

The Mammoth Site in Hot Springs, South Dakota preserves a unique death assemblage of sub-adult and adult male Columbian mammoths (Mammuthus columbi). Extensive work on the site has led to a detailed understanding of the taphonomy of the assemblage; yet the life histories and ecology of these mammoths remain relatively unknown. Tooth enamel from four Mammoth Site mammoth individuals were bulk sampled with one of the individuals (MSL 742) also serially micro-sampled for 𝛿13C, 𝛿18O, and 87Sr/86Sr. Isotopic results indicate that MSL 742 remained within the southern and western Black Hills …


Gravel Geology And Muskoxen Paleontology Of A Late Pleistocene Fossil Site In Saltville, Virginia, Nickolas A. Brand May 2021

Gravel Geology And Muskoxen Paleontology Of A Late Pleistocene Fossil Site In Saltville, Virginia, Nickolas A. Brand

Electronic Theses and Dissertations

Two distinct studies within the Saltville Valley of southwestern Virginia revealed insights into local Pleistocene geology and paleontology. A variety of analytical techniques were applied to gravel deposits within the paleontological site of SV-5/7 that revealed this unit is very poorly sorted, has a subangular matrix, and contains significant components of silt and sand in addition to rounded cobbles. These results suggest that rather than being deposited by fluvial processes as previously suggested, these gravels were likely the result of one or many debris flows. Additionally, the identity of fossil muskoxen from Saltville was reassessed using cranial and dental material. …


Morphology And Paleoecology Of Nimravides Galiani (Felidae) And Barbourofelis Loveorum (Barbourofelidae) From The Late Miocene Of Florida, Christianne Ormsby May 2021

Morphology And Paleoecology Of Nimravides Galiani (Felidae) And Barbourofelis Loveorum (Barbourofelidae) From The Late Miocene Of Florida, Christianne Ormsby

Electronic Theses and Dissertations

Saber-toothed remains have been found worldwide throughout the Cenozoic, until the end of the Pleistocene. One site from Alachua County, Florida preserves a diverse Miocene fauna, including the machairodontine Nimravides galiani (Felidae) and the saber-toothed Barbourofelis loveorum (Barbourofelidae). Both taxa roamed what would become the Love Bone Bed site during the Late Miocene (Late Clarendonian NALMA), ~ 9.5 Mya. Previous descriptions focused on crania; yet the large sample of postcrania remained undescribed. Hence, this project includes a detailed postcranial description of both taxa. Results show that N. galiani resembles extant felids, whereas B. loveorum resembles Smilodon fatalis, as well …


Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause Aug 2020

Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause

Electronic Theses and Dissertations

The Saltville valley in southwestern Virginia is home to Quaternary localities containing paleontological and archaeological remains. Historically the valley has been mined for salt and the small lakes, ponds and springs along the valley floor have a brackish signature. A preliminary report on the site’s ostracode fauna suggested that the site’s water was not always saline. This study analyzed modern and Quaternary ostracodes to understand the valley’s hydrologic and chemical evolution. Sediments contained primarily freshwater species, including the environmentally sensitive Candona crogmaniana. The presence of Pelocypris tuberculatum and a new Fabaeformiscandona species throughout a vertical section spanning the latest Pleistocene …


Encephalization In Commensal Raccoons: A Unique Test Of The Cognitive Buffer Hypothesis, Peter M. Anderson May 2020

Encephalization In Commensal Raccoons: A Unique Test Of The Cognitive Buffer Hypothesis, Peter M. Anderson

Electronic Theses and Dissertations

This study investigated selective pressures associated with encephalization in mammals and discussed broader implications. Relative brain size as measured by EQ (Encephalization Quotient) was compared between ecological categories. Omnivores had higher average EQ than ecological specialists. Since specialists are disproportionately affected by extinction events, selection for ecological generalism is proposed as encephalization mechanism. This mechanism may reinforce the more widely known Cognitive Buffer Hypothesis (CBH)—the idea that possessing relatively large brains has buffered lineages against environmental change. CBH is tested here by comparing EQs in Procyon lotor (raccoon) in urban and rural environments. CBH predicts that raccoons in the most …


Ontogenetic And Adult Shape Variation In The Endocast Of Tapirus: Implications For T. Polkensis From The Gray Fossil Site, Thomas M. Gaetano May 2020

Ontogenetic And Adult Shape Variation In The Endocast Of Tapirus: Implications For T. Polkensis From The Gray Fossil Site, Thomas M. Gaetano

Electronic Theses and Dissertations

Endocranial morphology provides evidence of sensory ecology and sociality of extinct vertebrates. The Earliest Pliocene Gray Fossil Site (GFS) of NE Tennessee features a conspicuous dominance of skeletal elements belonging to the dwarf tapir, Tapirus polkensis. Numerous individuals in one fossil locality often suggests gregarious behavior, but sociality in T. polkensis contradicts behavior documented for extant Tapirus species. I test T. polkensis for variation in sensory and social ecology using computed tomography and 3D digital endocasts from an ontogenetic sequence. I compare the T. polkensis endocasts with extant Tapirus species using Encephalization Quotients (EQs) and 3D geometric morphometrics. Results …


An Unusual Mastodon Revisited: Providing A Regional Focus For Mammut Americanum (Proboscidea, Mammutidae) In The Southeast, Matthew Inabinett May 2020

An Unusual Mastodon Revisited: Providing A Regional Focus For Mammut Americanum (Proboscidea, Mammutidae) In The Southeast, Matthew Inabinett

Electronic Theses and Dissertations

A century ago, two large American mastodon Mammut americanum specimens from coastal South Carolina were mounted for display at Amherst College. Their robust build, broad and pentalophodont third molars, and well-developed mandibular tusks were noted as unusual. Here, these specimens are redescribed; three additional mastodon mandibles from the same region of South Carolina are also described. Though collection information on these specimens is sparse, they appear to span >150 ka in the Middle to Late Pleistocene, and probably include the first report of Mammut from the earliest-Rancholabrean Ten Mile Hill Formation. Some “unusual” features — moderately to extremely broad third …


Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap May 2019

Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap

Electronic Theses and Dissertations

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 …


Paleoecology And Land-Use Of Quaternary Megafauna From Saltville, Virginia, Emily Simpson May 2019

Paleoecology And Land-Use Of Quaternary Megafauna From Saltville, Virginia, Emily Simpson

Electronic Theses and Dissertations

Land-use, feeding habits, and response to seasonality by Quaternary megaherbivores in Saltville, Virginia, is poorly understood. Stable isotope analyses of serially sampled Bootherium and Equus enamel from Saltville were used to explore seasonally calibrated (δ18O) patterns in megaherbivore diet (δ13C) and land-use (87Sr/86Sr). Overall, this dataset suggests an open forest with relatively constant temperatures year round that were similar to modern conditions. Neither Bootherium or Equus individuals spent a significant amount of time at higher elevations in the nearby Blue Ridge geologic province. These analyses provide a unique perspective on long-term response …


Postcranial Morphology And The Locomotor Adaptations Of Extant And Extinct Crocodylomorphs And Lepidosaurs, Laura Rooney May 2018

Postcranial Morphology And The Locomotor Adaptations Of Extant And Extinct Crocodylomorphs And Lepidosaurs, Laura Rooney

Electronic Theses and Dissertations

I have collected a series of linear measurements of the postcranial skeletons of 43 extant crocodylian and lepidosaur taxa to determine if those engaging in similar locomotor behavior display similar morphology despite phylogenetic differences. Stepwise discriminant function analyses reveal reptile locomotor mode can be accurately predicted (over 80% correct) based on morphology. Semi-aquatic taxa are distinguished by a longer ischium relative to pubis length, a longer scapula relative to humerus length, and a broader acetabulum than terrestrial and arboreal taxa. Arboreal taxa display a more elongate, gracile humerus and a smaller acetabulum. This morphometric data can potentially be used to …


Fossil Moles From The Gray Fossil Site, Tn: Implications For Diversification And Evolution Of North American Talpidae, Danielle Oberg May 2018

Fossil Moles From The Gray Fossil Site, Tn: Implications For Diversification And Evolution Of North American Talpidae, Danielle Oberg

Electronic Theses and Dissertations

The Gray Fossil Site (GFS) is one of the richest Cenozoic terrestrial localities in the eastern United States. This study describes the first talpid specimens recovered from the GFS. Using measurements and comparisons of dental and humerus morphology, I identify 4 talpids (Parascalops nov. sp., Quyania cf. Q. europaea, Mioscalops (= Scalopoides) sp., and an unidentified stem desman) occurring at the GFS. Humeral morphology has been used to diagnose talpid species and study relationships. A geometric morphometric analysis showed that humerus shape is highly reflective of locomotor ecology in extant talpids and allows ecological inferences for fossil …


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 …


Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej May 2017

Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej

Electronic Theses and Dissertations

Fossil Agamidae from Western Australia have been the subject of limited study. To aid in fossil agamid identification, Hocknull (2002) examined the maxilla and dentary of several extant species from Australia and determined diagnostic characters for various species groups. In the study here, fossil agamids from two localities in Western Australia, Hastings Cave and Horseshoe Cave, were examined, grouped, and identified to the lowest unambiguous taxonomic level. Morphometric analyses were conducted to compare morphotypes, and find additional diagnostic characters. From Hastings Cave there were two maxilla morphotypes and three dentary morphotypes. Based on identifications, taxa present at this locality were …


Black Bears (Ursus Americanus) Versus Brown Bears (U. Arctos): Combining Morphometrics And Niche Modeling To Differentiate Species And Predict Distributions Through Time, Theron Michael Kantelis May 2017

Black Bears (Ursus Americanus) Versus Brown Bears (U. Arctos): Combining Morphometrics And Niche Modeling To Differentiate Species And Predict Distributions Through Time, Theron Michael Kantelis

Electronic Theses and Dissertations

Late Pleistocene American black bears (Ursus americanus) often overlap in size with Pleistocene brown bears (U. arctos), occasionally making them difficult to diagnose. Large U. americanus have previously been distinguished from U. arctos by the length of the upper second molar (M2). However, the teeth of fossil U. americanus sometimes overlap size with U. arctos. As such, there is need for a more accurate tool to distinguish the two species. Here, 2D geometric morphometrics is applied to the occlusal surface of the M2 to further assess the utility of this tooth for distinguishing U. americanus and …


Description Of Cranial Elements And Ontogenetic Change Within Tropidolaemus Wagleri (Serpentes: Crotalinae)., Nicolette L. Hill May 2016

Description Of Cranial Elements And Ontogenetic Change Within Tropidolaemus Wagleri (Serpentes: Crotalinae)., Nicolette L. Hill

Electronic Theses and Dissertations

Tropidolaemus wagleri is a species of Asian pitviper with a geographic range including Thailand, Vietnam, Malaysia, Singapore, Bruniei, parts of Indonesia, and the hilippines. Tropidolaemus is a member of the Crotalinae subfamily, within Viperidae. The genus Tropidolaemus includes five species, and was once included within the genus Trimeresurus. While some osteologic characteristics have been noted a comprehensive description of cranial elements has not been produced for T. wagleri. An in-depth description of the cranial skeleton of Tropidolaemus wagleri lays the foundation for future projects to compare and contrast other taxa within Crotalinae and Viperidae. The chosen reference specimen …


Description, Taphonomy, And Paleoecology Of The Late Pleistocene Peccaries (Artiodactyla: Tayassuidae) From Bat Cave, Pulaski County, Missouri, Aaron L. Woodruff May 2016

Description, Taphonomy, And Paleoecology Of The Late Pleistocene Peccaries (Artiodactyla: Tayassuidae) From Bat Cave, Pulaski County, Missouri, Aaron L. Woodruff

Electronic Theses and Dissertations

The late Pleistocene faunal assemblage from Bat Cave, central Ozarks, Missouri provides an opportunity to assess specific aspects of behavior, ecology, and ontogeny of the extinct peccary Platygonus compressus. All identifiable elements referable to this taxon were catalogued and examined, and a minimum number of individuals of 70 was determined for the sample. The presence of distinct, non-overlapping age groups suggests that P. compressus utilized Bat Cave on a seasonal basis. A predator-prey relationship with Canis dirus, the second most abundant vertebrate from the Bat Cave site, is also described in this study. Damage patterns suggest that the …


Peccaries (Artiodactyla: Tayassuidae) From The Late Miocene To Early Pliocene Gray Fossil Site: Regional Implications With A Review Of Tayassuinae, Evan M. Doughty May 2016

Peccaries (Artiodactyla: Tayassuidae) From The Late Miocene To Early Pliocene Gray Fossil Site: Regional Implications With A Review Of Tayassuinae, Evan M. Doughty

Electronic Theses and Dissertations

Analysis of the Gray Fossil Site peccary material indicates the presence of up to three species. Comparisons with the tayassuid material known from the Tyner Farm and Bone Valley Formation of Florida allows the identification of Mylohyus elmorei and at the GFS. Within the GFS material, Prosthennops cf. P. serus and cf. Catagonus sp. are also tentatively recognized but further verification is required. The known range for Prosthennops is expanded into the Appalachian region. Presence of M. elmorei at the Gray Fossil Site provides the first known occurrence of this species outside of the Palmetto fauna of Florida, indicating that …


New Records Of Colubrids From The Late Hemphillian Gray Fossil Site Of Northeastern Tennessee, Derek J. Jurestovsky May 2016

New Records Of Colubrids From The Late Hemphillian Gray Fossil Site Of Northeastern Tennessee, Derek J. Jurestovsky

Electronic Theses and Dissertations

The Gray Fossil Site is a rich Hemphillian (North American Land Mammal Age) locality located in northeastern Tennessee which has produced tens-of-thousands of fossils of multiple taxa including hundreds of individual snake skeletal remains. Analyzed here are cranial and vertebral fossils identified as belonging to various colubrid taxa including Carphophis sp., Gyalopion sp., Heterodon sp., Natricinae indeterminate, Thamnophis sp., and a new, undescribed genus and species. In addition, multiple new features of snake vertebrae are described, some of which question the validity of the genus Neonatrix. Finally, the distribution and paleoecology of the listed genera allows an interpretation of …


Ontogenesis In The Cranium Of Alligator Mississippiensis Based On Disarticulated Cranial Elements, William Henry Harris May 2015

Ontogenesis In The Cranium Of Alligator Mississippiensis Based On Disarticulated Cranial Elements, William Henry Harris

Electronic Theses and Dissertations

The American alligator, Alligator mississippiensis, is a large extant archosaur and member of the Order Crocodilia. Crocodilian ontogeny has been studied in great detail, the skull being of particular interest. One aspect of the skull left unstudied is how individual cranial elements change through ontogeny independent of one another. This study observed morphological change in a growth series of 34 specimens of A. mississippiensis from ETSU Vertebrate Paleontology Lab collections. The premaxilla, maxilla, nasal, jugal, frontal, and parietal were analyzed using landmark morphometrics. The frontal, jugal, and parietal showed more allometric growth with the orbits reducing in size posteriorly. …