Open Access. Powered by Scholars. Published by Universities.®

Paleontology Commons

Open Access. Powered by Scholars. Published by Universities.®

1,460 Full-Text Articles 1,170 Authors 105,185 Downloads 83 Institutions

All Articles in Paleontology

Faceted Search

1,460 full-text articles. Page 3 of 22.

Late Quaternary Chorus Frog (Pseudacris) From The Channel Islands, California, Jim I. Mead, Justin Wilkins, Paul W. Collins 2018 Mammoth Site of Hot Springs South Dakota

Late Quaternary Chorus Frog (Pseudacris) From The Channel Islands, California, Jim I. Mead, Justin Wilkins, Paul W. Collins

Bulletin of the Southern California Academy of Sciences

Abstract.-Fossil and subfossil remains of the vertebrate faunas from the northern Channel Islands, southern California, have been studied for many decades. Continued interest has focused on skeletal remains of birds, rodents, and mammoths from archaeological and paleontological localities, but considerably less attention has been placed on the detailed description of the herpetofauna (salamanders, anurans [frogs and toads], lizards, and snakes) on the Channel Islands. We present descriptions of an ilium of an anuran from Santa Rosa Island (Larramendy North; radiocarbon dating at least 13,393 calibrated years ago) and two tibiofibulae San Miguel Island (Daisy Cave) dating from earliest ...


Analysis Of A Mammalian Fauna From The Fort Union Formation, Great Divide And Washakie Basins, Wyoming, Nicole Marie Neu-Yagle 2018 University of Colorado at Boulder

Analysis Of A Mammalian Fauna From The Fort Union Formation, Great Divide And Washakie Basins, Wyoming, Nicole Marie Neu-Yagle

Museum and Field Studies Graduate Theses & Dissertations

Early and middle Paleocene mammalian faunas are documented throughout the North American Western Interior. Faunas near, or spanning, the Torrejonian-Tiffanian transition have been reported by others from Wyoming’s Hanna, Carbon, and Bighorn basins and are important for assessing this transition period which has many overlapping mammalian occurrences. Reported here is a later Torrejonian (To2 or To3) mammalian fauna from the upper China Butte Member of the Fort Union Formation in Wyoming’s Great Divide and Washakie Basins (GDB & WB). The GDB & WB assemblage is comprised of isolated mammal teeth, collected primarily from anthill localities, and is a representation of ...


Nitrogen Isotopes Suggest A Change In Nitrogen Dynamics Between The Late Pleistocene And Modern Time In Yukon, Canada, Farnoush Tahmasebi, Fred J. Longstaffe, Grant Zazula 2018 The University of Western Ontario

Nitrogen Isotopes Suggest A Change In Nitrogen Dynamics Between The Late Pleistocene And Modern Time In Yukon, Canada, Farnoush Tahmasebi, Fred J. Longstaffe, Grant Zazula

Earth Sciences Publications

A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and ...


Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris 2018 University of Kentucky

Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris

Theses and Dissertations--Earth and Environmental Sciences

Well-preserved echinoderm faunas are rare in the fossil record, and when uncovered, understanding their occurrence can be useful in interpreting other faunas. In this study, two such faunas of the same age from separate localities in the shallow-marine Ramey Creek Member of the Slade Formation in the Upper Mississippian (Chesterian) rocks of eastern Kentucky are examined. Of the more than 5,000 fossil specimens from both localities, only 9–34 percent were echinoderms from 3–5 classes. Nine non-echinoderm (8 invertebrate and one vertebrate) classes occurred at both localities, but of these, bryozoans, brachiopods and sponges dominated. To understand the ...


Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green 2018 Fort Hays State University

Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green

Master's Theses

Clidastes was a large marine reptile from the Late Cretaceous Western Interior Seaway of North America. Though the remains of Clidastes have been found in the Cretaceous chalks and shales for over 150 years, little is known about their growth rates.

Osteohistology is a well-documented technique used to investigate growth in extinct animals. Previous histological studies of Clidastes have hypothesized higher growth rates in basal mosasaurids than varanids due to higher vascularity. These studies focused on adult specimens but did not look at ontogenetic changes in growth rates. Isotopic studies of Clidastes indicate high metabolic temperatures, leading to speculation these ...


Aquatic Ecosystem Response To Late Pleistocene And Holocene Climate Variations : A Palaeolimnological Investigation Of Three Lakes On Fraser Island, Australia, Sarah Hembrow 2018 Southern Cross University

Aquatic Ecosystem Response To Late Pleistocene And Holocene Climate Variations : A Palaeolimnological Investigation Of Three Lakes On Fraser Island, Australia, Sarah Hembrow

Theses

High resolution palaeoecological data is a valuable tool to determine past climate variability and ecological responses. This thesis examined the aquatic community response of three lakes on Fraser Island using biological and geochemical records for the last 18,000 years. The lake records demonstrate a trend of decreasing precipitation throughout the late Holocene, with increased climatic variability represented by episodic events. From these records, a more detailed knowledge of climate change in eastern Australia during the Holocene has been identified.


Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad 2018 The College of Wooster

Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad

Senior Independent Study Theses

The Campanian Stage of the Upper Cretaceous was established by Henri Coquand in 1857 based on a sequence of richly fossiliferous shallow water carbonates in the Charente and Charente-Maritime departments of southwestern France. One of the most common macrofossils is the gryphaeid oyster Pycnodonte vesicularis (Lamarck, 1806), which often forms extensive shell beds. This bivalve lived primarily on soft marly substrates, forming hard substrate islands. They frequently supported sclerobiont communities comprising encrusters (diverse cheilostome and cyclostome bryozoans, foraminiferans, oysters, bivalves, sabellid and serpulid polychaetes, calcareous sponges), borers (the sponge borings Entobia, the worm borings Maeandropolydora and Caulostrepsis, the barnacle borings ...


Interactive Map Portal Of Some Important Fossil Localities Along The Southern Tethyan Margin Of The Sephardic (Triassic) And Ethiopian (Jurassic) Faunal Provinces, Marcelo Rosensaft, Howard R. Feldman 2018 Touro College

Interactive Map Portal Of Some Important Fossil Localities Along The Southern Tethyan Margin Of The Sephardic (Triassic) And Ethiopian (Jurassic) Faunal Provinces, Marcelo Rosensaft, Howard R. Feldman

Lander College for Women - The Anna Ruth and Mark Hasten School Publications and Research

The use of a “map portal” allows researchers to publish their maps and the data incorporated therein in a simple way that will reach a broad audience. Colleagues, as well as other workers worldwide, can connect to the portal through the internet and display the maps on desktop computers. The process is dynamic; any change made in the source map is immediately displayed on the user’s desktop. In this report we illustrate a map of Triassic and Jurassic brachiopod collecting localities on the southern Tethyan margin in the Middle East. The locations are shown as red points that overlie ...


The Triassic Saharonim Formation Of The Sephardic Province On The Southern Tethyan Margin Is An Analog For The Triassic Germanic Muschelkalk Of Western Europe, Howard R. Feldman, Talia J. Belowich 2018 Touro College

The Triassic Saharonim Formation Of The Sephardic Province On The Southern Tethyan Margin Is An Analog For The Triassic Germanic Muschelkalk Of Western Europe, Howard R. Feldman, Talia J. Belowich

Lander College for Women - The Anna Ruth and Mark Hasten School Publications and Research

The Germanic Muschelkalk consists of a sedimentary sequence of limestone and dolostone units that overlies the Permian Buntsandstein Formation and underlies the Middle and Late Triassic Keuper Formation. The three formations form the Germanic Triassic Supergroup. The Muschelkalk was deposited in a shallow marine environment that was only partially connected to the Tethys Ocean to the south with the middle section evaporitic indicating a restricted basin. Fossiliferous beds are often biostromal such as the well-known Coenothyris brachiopod beds (e.g. Terebratula Bed, terebratulid facies) common in the Muschelkalk. The Saharonim Formation of the Sephardic Province, found along the southern shore ...


Volcanogenic Pseudo-Fossils From The ~3.48 Ga Dresser Formation, Pilbara, Western Australia, David Wacey, Nora Noffke, Martin Saunders, Paul Guagliardo, David M. Pyle 2018 Old Dominion University

Volcanogenic Pseudo-Fossils From The ~3.48 Ga Dresser Formation, Pilbara, Western Australia, David Wacey, Nora Noffke, Martin Saunders, Paul Guagliardo, David M. Pyle

OEAS Faculty Publications

The ~ 3.48 billion-year-old Dresser Formation, Pilbara Craton, Western Australia, is a key geological unit for the study of Earth's earliest life and the habitats it occupied. Here, we describe a new suite of spheroidal to lenticular microstructures that morphologically resemble some previously reported Archean microfossils. Correlative microscopy shows that these objects have a size distribution, wall ultrastructure, and chemistry that are incompatible with a microfossil origin and instead are interpreted as pyritized and silicified fragments of vesicular volcanic glass. Organic kerogenous material is associated with much of the altered volcanic glass; variable quantities of organic carbon line or ...


Evolution Of The Modern Baboon (Papio Hamadryas): A Reassessment Of The African Plio-Pleistocene Record, Christopher C. Gilbert, Stephen R. Frost, Kelsey D. Pugh, Monya Anderson, Eric Delson 2018 CUNY Hunter College

Evolution Of The Modern Baboon (Papio Hamadryas): A Reassessment Of The African Plio-Pleistocene Record, Christopher C. Gilbert, Stephen R. Frost, Kelsey D. Pugh, Monya Anderson, Eric Delson

Publications and Research

Baboons ( Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi , Papio robinsoni and Papio angusticeps. Because of their derived appearance, P. angusticeps and P. robinsoni have sometimes been considered subspecies of P. hamadryas and have been used as biochronological markers for the Plio- Pleistocene hominin sites where they are found.

We reexamined fossil Papio forms from across Africa with an emphasis on their distinguishing features and distribution. We ...


Refinement And Utilization Of The Marine Climate Proxy Arctica Islandica: An Ideal Replication Strategy For Stable Isotope Studies And An Investigation Into The Shell Growth And Hydrographic Variability Of Georges Bank (Northwestern Atlantic), Jared Daniel Brenzink Ballew 2018 Iowa State University

Refinement And Utilization Of The Marine Climate Proxy Arctica Islandica: An Ideal Replication Strategy For Stable Isotope Studies And An Investigation Into The Shell Growth And Hydrographic Variability Of Georges Bank (Northwestern Atlantic), Jared Daniel Brenzink Ballew

Graduate Theses and Dissertations

This thesis presents two studies that discuss the further refinement and utilization of the marine climate proxy Arctica islandica. The first study uses a Monte Carlo simulation to examine the relationship between replication and uncertainty for climate reconstructions utilizing oxygen isotopes, carbon isotopes and temperature estimates (derived from the modified Grossman and Ku [1986] equation) from the climate proxy A. islandica. An uncertainty within the 95% confidence interval occurred when using two or three shells. An increase to four shells further reduced the uncertainty to within the 99% confidence interval. Studies that utilize stable isotope ratios from A. islandica shells ...


The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard 2018 University of Nebraska-Lincoln

The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard

Conservation and Survey Division

The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Red Willow County that has not been published in readily accessible formats previously. Many of the maps presented here are based on geologic information from registered wells and test holes that is publically available on-line, which becomes more valuable when compiled, analyzed, and discussed as a whole.

In Red Willow County, the aquifers are alluvial sand and gravel in the river and stream valleys and the High Plains aquifer beneath the uplands. The High Plains aquifer in Red Willow County consists primarily of the Ogallala ...


Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus 2018 University of Nebraska-Lincoln

Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus

Conservation and Survey Division

Impermeable aquifer boundaries affect the flow of groundwater, transport of contaminants, and the drawdown of water levels in response to pumping. Hydraulic methods can detect the presence of such boundaries, but these methods are not suited for mapping complex, 3D geological bodies. Airborne electromagnetic (AEM) methods produce 3D geophysical images of the subsurface at depths relevant to most groundwater investigations. Interpreting a geophysical model requires supporting information, and hydraulic heads offer the most direct means of assessing the hydrostratigraphic function of interpreted geological units. This paper presents three examples of combined hydraulic and AEM analysis of impermeable boundaries in glacial ...


The Integration Of Morphology, Variation, And Phylogenetics To Better Understand Fossil Taxa And Their Modern Relatives, Steven E. Jasinski 2018 University of Pennsylvania

The Integration Of Morphology, Variation, And Phylogenetics To Better Understand Fossil Taxa And Their Modern Relatives, Steven E. Jasinski

Publicly Accessible Penn Dissertations

Morphology, or shapes, particularly of bones, is important for understanding how animals vary and, therefore, for understanding diversity. Comparison of morphology in animals can be used to make inferences on fossil organisms. At its base, fossil specimens are described and compared with other fossil and modern specimens, often to determine if they represent a new and distinct species, thereby increasing observed biodiversity through time. Dromaeosaurids (family Dromaeosauridae) are a group of dynamic, swift predatory dinosaurs, that have a sparse fossil record, particularly at the time of their extinction near the Cretaceous-Paleogene boundary. A recently recovered specimen from the latest Cretaceous ...


Evidence For Ephemeral Middle Eocene To Early Oligocene Greenland Glacial Ice And Pan-Arctic Sea Ice, Aradhna Tripati, Dennis Darby 2018 Old Dominion University

Evidence For Ephemeral Middle Eocene To Early Oligocene Greenland Glacial Ice And Pan-Arctic Sea Ice, Aradhna Tripati, Dennis Darby

OEAS Faculty Publications

Earth's modern climate is defined by the presence of ice at both poles, but that ice is now disappearing. Therefore understanding the origin and causes of polar ice stability is more critical than ever. Here we provide novel geochemical data that constrain past dynamics of glacial ice on Greenland and Arctic sea ice. Based on accurate source determinations of individual ice-rafted Fe-oxide grains, we find evidence for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene. Glacial intervals broadly coincide with ...


Cataloging Wonder: The Art And Science Of The Collection, Christine Metzger 2017 California College of the Arts

Cataloging Wonder: The Art And Science Of The Collection, Christine Metzger

The STEAM Journal

The Exploring Science in the Studio National Science Foundation grant funded three initiatives at California College of the Arts, a private four-year art and design college in the San Francisco Bay Area. The grant sponsored annual Science-in-the-Studio which embedded scientists into the art and design studio curriculum, the creation of Mobile Units for Scientific Exploration (MUSE) and a new collection of science materials, equipment, and natural specimens, and a national symposium on integrating science into the art and design studio curriculum. Approximately 30 SitS classes have been offered since 2010, and the Exploring Science in the Studio symposium was convened ...


Ordovician Continental Paleogeography And Paleoenvironment For The Michigan Basin From Paleomagnetic Analysis, Michelle MacRae 2017 The University of Western Ontario

Ordovician Continental Paleogeography And Paleoenvironment For The Michigan Basin From Paleomagnetic Analysis, Michelle Macrae

Electronic Thesis and Dissertation Repository

This study investigates the paleomagnetic record of Paleozoic rocks from two Michigan basin localities in southwestern Ontario to help close the 40 myr gap in Paleozoic paleomagnetic data. Paleomagnetic data from the Queenston (Upper Ordovician) formation consistently exhibits easily removed viscous remanence, an intermediate and a high temperature component consistent with the unblocking temperatures of magnetite and hematite respectively. Alternating-field and thermal demagnetization in 16–20 steps up to 670º C typically reveal a southeastern, shallow up direction removed from magnetite, and a southwestern, steep up direction removed from hematite. A Late Paleozoic overprint was preserved in the magnetite and ...


A Method For The Geometric Analysis Of Rugose Coral Growth Ridges As Paleoenvironmental Indicators In The Middle Devonian Hungry Hollow Member Of Widder Formation, Michigan Basin, Andrew Thomson 2017 The University of Western Ontario

A Method For The Geometric Analysis Of Rugose Coral Growth Ridges As Paleoenvironmental Indicators In The Middle Devonian Hungry Hollow Member Of Widder Formation, Michigan Basin, Andrew Thomson

Electronic Thesis and Dissertation Repository

Skeletons of Devonian rugose corals feature submillimetre-scale growth ridges on their outer surface (epitheca) that record the successive positions of the coral polyp during longitudinal corallite growth. Specimens of rugose corals Eridophyllum and Cystiphylloides from the Hungry Hollow Member of the Middle Devonian Widder Formation were sectioned longitudinally and imaged by SEM, and image processing techniques were applied to extract a line representing the epithecal surface. Local extrema found through peak detection allowed growth ridges to be represented as simplified triangles, so that geometric measurements (area, length) could be related to coral growth and analyzed in reference to possible paleoenvironmental ...


Aquifers Of Nebraska Ii: The Niobrara Aquifer, Dana Divine, Robert Matthew Joeckel, Sue Olafsen Lackey 2017 University of Nebraska-Lincoln

Aquifers Of Nebraska Ii: The Niobrara Aquifer, Dana Divine, Robert Matthew Joeckel, Sue Olafsen Lackey

Conservation and Survey Division

The marine shale, chalk, marl, and chalky limestone of the Niobrara Formation directly underlie Quaternary sediments in 23 counties from south-central to northeastern Nebraska. Nevertheless, the formation serves as an aquifer only in and around Cedar, Madison, and Nuckolls counties. Niobrara aquifer wells mostly supply irrigation, domestic, and livestock needs. Two hundred of the approximately 230 active registered wells in Nebraska that are screened entirely in the Niobrara aquifer are in Cedar County and environs. About another 200 wells in this area are screened in both the Niobrara aquifer and overlying Quaternary sediments. Wells screened entirely in the Niobrara aquifer ...


Digital Commons powered by bepress