Paleontology Commons^™

Analysis Of Legacy Gravity Data Reveals Sediment-Filled Troughs Buried Under Flathead Valley, Montana, Usa, Ali Gebril, Mohamed A. Khalil, Robert Matthew Joeckel, James Rose

Conservation and Survey Division: Faculty and Staff Publications

Shallow, dominantly silt- and clay-filled erosional troughs in Quaternary sediments under the Flathead Valley (northwestern Montana, USA) are very likely to be hydraulic barriers limiting the horizontal flow of groundwater. Accurately mapping them is important because of increasing demand for groundwater.We used a legacy Bouguer gravity map measured in 1968. The directional derivatives of the map are computed, and the map was enhanced by implementing edge detection tools.We produced generalized derivative, maximum horizontal gradient, total gradient and tilt gradient maps through two-dimensional Fourier transform analysis. These maps were remarkably successful in locating buried troughs in the northern and northwestern parts …

Cambrian Trilobites From The Nounan Dolomite And Lower St. Charles Formation (Upper Marjuman To Lower Sunwaptan; Miaolingian To Furongian Series), Smithfield Canyon, Northern Utah, Frederick A. Sundberg, Hannah R. Cothren, Carol M. Dehler

Geosciences Faculty Publications

The trilobite faunas that occur with the Steptoean Positive Isotope Carbon Excursion (SPICE) at Smithfield Canyon, Utah, have been reported, but not illustrated. Given the importance of the SPICE at this section for international correlations, the trilobites from new collections from the upper Nounan Dolomite to lower St. Charles Formation at Smithfield Canyon are reported herein and integrated with the previously reported taxa. Trilobite assemblages indicate that the upper Cedaria to the Ellipsocephaloides biozones (Miaolingian Series, Guzhangian Stage to Furongian Series, Jiangshanian Stage) are present stratigraphically below or above the SPICE.

Some of the taxa reported herein may represent new …

Locating And Assessing Oregon Trail Ruts With Aerial Stereophotographs, Satellite Imagery And Lidar, P.R. Hanson, Robert Matthew Joeckel, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Hunting Types In North American Eocene And Oligocene Carnivores And Implications For Nimravid Extinction, Miguel Andres Castellanos

Graduate Research Theses & Dissertations

The late Eocene and Oligocene is traditionally seen as a time of great climactic shift, with open habitats beginning to appear and forests receding. This time period saw both the diversification and subsequent extinction of North American nimravids. The causes of the extinction of this early sabertooth group in the Arikareean remain unclear. One possibility for their decline is that nimravids were competitively disadvantaged in open habitats relative to contemporary, possibly more cursorial caniform predators. Here I analyze and compare the hunting styles of Eocene and Oligocene predators in correlation with their ecological implications via discriminant function analysis of the …

A Proxy System Modeling Approach To Combining Tree-Ring And Sediment-Based Paleotempestological Records, Elizabeth J. Wallace, Sylvia Dee, Joshua Bregy, Kerry A. Emanuel

OES Faculty Publications

The short and biased observational record of tropical cyclones (TCs) limits scientific understanding of how these destructive storms respond to climate forcing. Paleohurricane records use natural archives (tree rings, coarse-grained sediment) to reconstruct TC properties (frequency and intensity of rainfall, wind) over the past few hundreds to thousands of years. However, different sensitivities and sampling biases in the various paleohurricane proxies restrict our ability to compile these records into regional or basin-scale TC estimates. Here we test how well pseudo tree-ring records of paleohurricanes capture TC rainfall and occurrence. Using a large set of statistically downscaled storms forced with the …

Interpreting An Archaean Paleoenvironment Through 3d Imagery Of Microbialites, Cecilia M. Howard, Nathan D. Sheldon, Selena Y. Smith, Nora Noffke

OES Faculty Publications

While stromatolites, and to a lesser extent thrombolites, have been extensively studied in order to unravel Precambrian (>539 Ma) biological evolution, studies of clastic-dominated microbially induced sedimentary structures (MISS) are relatively scarce. The lack of a consolidated record of clastic microbialites creates questions about how much (and what) information on depositional and taphonomic settings can be gleaned from these fossils. We used μCT scanning, a non-destructive X-ray-based 3D imaging method, to reconstruct morphologies of ancient MISS and mat textures in two previously described coastal Archaean samples from the ~3.48 Ga Dresser Formation, Pilbara, Western Australia. The aim of this …

Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Statewide Groundwater-Level Monitoring Report 2023, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Nawaraj Shrestha, Jeffrey Westrop

Conservation and Survey Division: Faculty and Staff Publications

This report is a synthesis of groundwater-level monitoring programs in Nebraska. It is a continuation of the series of annual reports and maps produced by the Conservation and Survey Division (CSD) of the University of Nebraska in cooperation with the U.S. Geological Survey (USGS) since the 1950s. Groundwater-level monitoring began in Nebraska in 1930 to survey the state’s groundwater resources and observe changes in its availability on a regular basis. The CSD and USGS cooperatively developed, maintained, and operated an observation-well network throughout the state. These two agencies were responsible for collecting and archiving this information, and for making it …

Leveraging High Resolution Classifications And Random Forests For Hindcasting Decades Of Mesic Ecosystem Dynamics In The Landsat Time Series, N. E. Kolarik, Nawaraj Shrestha, T. Caughlin, J. S. Brandt

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Transient Electromagnetic (Tem) Survey For Targeted Drilling On The Kurtzhals Property, Cedar County, Nebraska, Jesse Korus, Katherine (Katie) Cameron, Michele Waszgis

Conservation and Survey Division: Faculty and Staff Publications

The Kurtzhals property is in Section 19, Township 30N, Range 3 in Cedar County, Nebraska. The present land use is agricultural row crop, but past use included hog production. Two active irrigation wells are located on adjacent properties to the west and southwest. An irrigation well was installed in the northwest corner of the property in 2022. Due to the low yield (300 gallons per minute) of this well, Mr. Kurtzhals seeks to install an additional irrigation well to supplement the first. Several unsuccessful test holes had been drilled prior to the present survey. The purpose of this survey was …

Multiscale Characterization Of Splays Produced By A Historic, Rain-On-Snow Flood On A Large Braided Stream (Platte River, Central Usa), J. T. Korus, R. M. Joeckel, A. R. Mittelstet, N. Shrestha

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Zircon Luminescence Dating Re-Visited, C. Schmidt, T. Halter, P.R. Hanson, A. Ulianov, B. Putlitz, G. E. King, S. Kreutzer

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Landscape And Paleoenvironmental Change In Stream Valleys Of The Central Great Plains, North America During Marine Isotope Stage 3 (Ca. 59-27 Ka)., T. Layzell, K. Andrzejewski, R. D. Mandel, P.R. Hanson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Age Dating Young Groundwater: How To Determine Groundwater Age From Environmental Tracer Data, D. K. Solomon, T. E. Gilmore

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Wetlands In The Nebraska Sandhills, Nawaraj Shrestha

Conservation and Survey Division: Faculty and Staff Publications

Infographic titled “Status of Wetlands in the Nebraska Sandhills” showing multiple maps and charts. The top left features a color-coded wetland persistence map where blue indicates more consistent wetlands and red indicates intermittent wetlands. Additional inset maps show a regional zoom and a U.S. location map highlighting Nebraska. A large scatter plot displays wetland occurrence percentages over time using MODIS (green points) and Sentinel (blue points) satellite data from 2000 to 2024. Text explains how wetlands vary seasonally and annually and how satellite imagery tracks these changes. A smaller bottom chart shows long-term wetland trends, noting increasing occurrence since 1984. …

Ontogenetically Driven Changes In The Endocranial Anatomy Of Maiasaura Peeblesorum And Its Implications For Sensory Functions, Emma Puetz

Masters Theses

"Hadrosaurids exhibited extreme morphological diversity and behavioral characteristics that can be compared with other, closely related members of Dinosauria – particularly through the study of neuroanatomy. X-ray CT generated endocrania of the Late Cretaceous saurolophine hadrosaur Maiasaura peeblesorum, known as the “good mother” dinosaur, offers a unique opportunity to compare complex ecological behaviors between non-avian dinosaurs and their modern archosaur relatives. The 3D reconstruction software ORS Dragonfly provided linear and volumetric measurements taken from the digital cranial endocast and endosseous labyrinths of three ontogenetically varied M. peeblesorum specimens from the Two Medicine Formation in Montana that were used to …

Analyzing The Shark Paleoecology Of Coastal Georgia From The Miocene And Pliocene Epochs, Joshua Lee Clark, Benjamin Angalet

Georgia Journal of Science

The field of shark paleoecology often yields indecisive conclusions based on the limited fossilization of their anatomical structures, with the exception of their teeth. The majority of the Atlantic coast has been studied regarding the presence of certain prehistoric shark species from the Miocene, Pliocene, and Pleistocene epochs. However, information pertaining to the Georgia coast and understanding its potential community structure is relatively understudied. This study was conducted in which thousands of fossil shark specimens and subsequent marine fauna were collected from dredge spoils created by the US Army Corps of Engineers (USACE): Savannah District. A total of 5,127 fossil …

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

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 …

Enhancing Our Understanding Of Ancient Oceans Through The Investigation Of Molybdenum Behavior Under Sulfidic Conditions, Rachel Faye Phillips

Open Access Theses & Dissertations

The most abundant trace metal in the ocean today, molybdenum (Mo), exhibits distinct behavior in oxygenated water, where it remains predominantly dissolved, compared to euxinic (i.e., oxygen-free and sulfidic) water, in which it is sequestered into the sediment. This dissimilar behavior allows us to use Mo concentrations and isotopic compositions in sediment to reconstruct marine oxygenation conditions throughout geologic history. However, Mo sequestration mechanisms under euxinic conditions remain unresolved, which limits the accuracy and precision of reconstructions made using Mo signatures in the rock record. For my doctoral research, I experimentally investigated abiotic and biotic Mo sequestration mechanisms under various …

Palynology Of The Gulf Of Mexico Stones Field Well Wr 508 #1: New Biostratigraphic And Environmental Data Of A Deepwater Wilcox Group, Barry G. Boler

LSU Master's Theses

Palynological analyses of Late Paleocene to Early Eocene drill cutting samples from the deepwater Wilcox Group in the northern Gulf of Mexico were analyzed to provide Paleocene/Eocene environmental data and to create a biosteering scheme to be used for future Gulf of Mexico exploration. Fifty-three drill cutting samples were analyzed from Walker Ridge (WR) 508 #1 in the Stones field, with a measured depth ranging from 8,056 to 8,723 m. These samples yielded mainly low diversity terrestrial assemblages dominated by pollen belonging to the Betulaceae, Myricaceae, Cupressaceae/Taxodiaceae and Juglandaceae families. This denotes an environment quite similar to what is found …

Pleistocene Bats (Late Irvingtonian And Late Rancholabrean) From Nuckolls And Sherman Counties, Nebraska, Nicholas J. Czaplewski, Richard George Corner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

We document rare finds of fossil bats from two localities representing the Pleistocene epoch in southern and central Nebraska, Albert Ahrens locality (No-104, late Irvingtonian age, Middle Pleistocene), Nuckolls County, and Litchfield (Sm-102, late Rancholabrean age, latest Pleistocene), Sherman County. The Albert Ahrens local fauna with strong boreal influence has produced two bats, Lasiurus cf. borealis and Cf. Myotis sp. The Litchfield local fauna, also showing a strong boreal influence, has yielded two bats, Eptesicus fuscus and Cf. Myotis, among a diverse Pleistocene fauna of small vertebrates and a pollen record indicating a boreal mixed conifer and deciduous woodland, …

Field Guide To Big Bone Lick, Kentucky: Birthplace Of American Vertebrate Paleontology, Glenn W. Storrs, H Gregory Mcdonald, Eric Scott, Robert A. Genheimer, Stanley E. Hedeen, Cameron E. Schwalbach

Special Publication--KGS

Big Bone Lick is the birthplace of vertebrate paleontology in the Western Hemisphere and has a long and celebrated history in the exploration of the American colonial frontier and of the early United States. Notable European scientists of the 18th century such as Buffon, Cuvier, and Hunter discussed the fossils found there. Prominent Americans of the time, such as Boone, Washington, Franklin, and Jefferson are also part of the site’s history. It is the type locality for several extinct late Pleistocene megafaunal mammals, most notably the iconic American Mastodon, who were attracted to the area by salt licks dictated by …

Changes In Paleobiodiversity Across The K-Pg Boundary In Oktibbeha County, Mississippi, Joshua Broussard

Theses and Dissertations

Evidence of the Cretaceous-Paleogene (K-Pg) extinction can be seen across the Mississippi Embayment, however research examining the K-Pg boundary in the state of Mississippi is lacking. The objective of this study addresses how macrofauna changed across the K-Pg boundary in Oktibbeha County, Mississippi and subsequent comparison to other Early Paleogene and Late Cretaceous benthic marine macrofaunal localities. Comparison included previously collected material as well as specimens collected during this study in order to reconstruct the biological community living on the seafloor in the earliest Paleocene Mississippi Embayment. The primary fauna present after the K-Pg extinction was mainly composed of small …

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

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 …

New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly

Electronic Theses and Dissertations

Dryolestoids are extinct cladotherians mammals from the Jurassic and Cretaceous periods. I describe a collection of dryolestoid specimens from the Late Cretaceous localities of Cerro Tortuga (Allen Formation), Anfiteatro 1, and Shining (both La Colonia Formation) from Patagonia, Argentina. Using comparative morphology, I identify a new species of meridiolestidan dryolestoid based on eleven specimens across both formations. The new species’ recovery from La Colonia Formation represents the first dryolestoid connection between the two approximately contemporaneous formations. The species’ morphology may represent an ecological shift within Meridiolestida from insectivory to herbivory, showing a transition in characters between the plesiomorphic sharp-toothed meridiolestidans …

History Of Ice-Rafting In The Arctic Ocean During Glacial Maxima Through Marine Isotope Stage 6, Shannon M. Cofield

OES Theses and Dissertations

Numerous studies attempted to reconstruct Arctic paleoclimate, specifically ice mass timing and locations, during glacial maxima. While some regions, like the Barents-Svalbard Ice Sheet (BSIS) are well-studied, they may benefit from a high-resolution paleo proxy. Other regions are highly contested, such as the East Siberian Sea or the presence of a central Arctic Ocean ice mass.

This research uses an Fe-grain provenance method to (1) define how the BSIS behaved during Marine Isotope Stage (MIS) 2, 4, and 6, and when it retreated; (2) determine the presence and ages of Shelf Ice Masses (SIMs) in the Beaufort Sea and East …

Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …