Paleobiology Commons^™

Updates To The Caniform Fauna (Carnivora, Caniformia) Of The John Day Formation, Oregon, Usa, John D. Orcutt, Kevin C. Talbott, Michael J. Monroe, Nicholas A. Famoso

Biology Faculty Scholarship

The John Day Formation of central Oregon preserves a diversity of Oligo-Miocene caniform carnivorans, many of which were first described from the formation. However, many historically important specimens lack detailed locality or stratigraphic information, complicating any analysis of faunal change through time. Here, we describe 16 new specimens of caniforms from the John Day Formation, most with precise stratigraphic information. We report multiple specimens of the amphicyonids Daphoenus Leidy, 1853, Paradaphoenus cuspigerus (Cope, 1878), and Temnocyon altigenis (Cope, 1878), all previously known from the formation. We also report the first definitive occurrence of the hesperocyonine canid Osbornodon Wang, 1994 from …

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad

University Honors Theses

Throughout the Phanerozoic, one of the most successful phyla of marine invertebrates has been Echinodermata. Echinodermata was particularly successful throughout the Paleozoic, with class Crinoidea making up a majority of occurrences. The proportion of echinoderm occurrences that are crinoids declined massively at the end of the Permian and continued to decrease into modern day, never fully recovering. One of the factors thought to have been so important for crinoid success in the Paleozoic and their decreasing success throughout geologic time has been their propensity for success in shallow-marine environments, though crinoids also exist within deep-marine environments. This study seeks to …

The Hitchhiker's Guide To The Host: Fleas And The History Of Pikas In North America, Josh Pletcher

All NMU Master's Theses

Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of …

Ontogeny And The Effects Of Perinatal Stress In The First Immature Skeleton Of Teleoceras Aepysoma (Perissodactyla, Rhinocerotidae), Joe Gajewski

Electronic Theses and Dissertations

Recovery of an immature fossil rhinoceros (Teleoceras aepysoma) skeleton (ETMNH 32999) from the Gray Fossil Site in Tennessee offers the first insights into the ontogeny of the species. ETMNH 32999 is interpreted to be a subadult male in an age class equivalent to ~17-20% of potential lifespan. Comparative analyses support the hypothesis that subadults of related taxa are typically ~91% of average adult size in most dimensions. However, certain cranial dimensions are substantially lower than expected in ETMNH 32999, averaging only ~74% of the average conspecific adult. Such departure from typical growth rates is suggested to be attributable …

Mandibular Ecomorphology Of Tylosaurus (Reptilia: Mosasauridae), Andrew I. Price, Amanda Peng

SACAD: Scholarly Activities

The large mosasaur Tylosaurus is known to have been a predator of large marine animals. Performing beam theory analysis, a computational technique that uses linear dimensions of a structure to calculate its resistance to bending, on the mandibles of six Tylosaurus specimens from the Smoky Hill Chalk of Kansas indicates dorsoventral and mediolateral bending strength both increase posteriorly along the mandible. Comparisons with Varanus komodoensis indicate relatively greater mediolateral bending strength mid-dentary in Tylosaurus, suggesting that resisting torsional forces of struggling prey was more important at this landmark in Tylosaurus and that more of its jaw length was used …

Overview And Methods Of Molecular Paleontology: A Review, Shelby Touchstone

Williams Honors College, Honors Research Projects

Molecular paleontology—the study of ancient biomolecules preserved in fossils and sediments, including ancient DNA, lipids, and proteins—has motivated researchers since the 1950s, inspiring both scientific inquiry and broader cultural imagination. Think Jurassic Park. This honors thesis presents a comprehensive review of the history, current state, and methods of the field of molecular paleontology. Drawing on peer-reviewed literature and scholarly resources accessed through databases such as EBSCO and Bierce library, this review examines key techniques such as Next Generation Sequencing and amino acid racemization and will go over limitations and controversies in the field. It will also explore potential new …

A Multi-Isotope Investigation Of Mammoth Diet, Habitat, And Movement Patterns In The Central Great Plains, U.S.A., Jacob Mccloskey

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

During the Last Glacial Maximum (LGM), the Great Plains in Nebraska consisted of wooded parklands and grasslands, whereas spruce (Picea) forests, parklands, and steppe grasslands dominated east of the Missouri River. I analyzed bulk carbon (δ¹³C), oxygen (δ¹⁸O), and strontium (⁸⁷Sr/⁸⁶Sr) isotopes from tooth enamel in isolated mammoth (Mammuthus) molars to compare diet and movement patterns in two late Pleistocene assemblages: one in Nebraska (n = 24), and one in western Iowa and Missouri (n = 17). Furthermore, I identified a morphometric subset of molars as …

Ediacaran Paleocommunity Structure, Body Size Evolution, And The Rise Of Complex Animals, Matthew Philip Craffey

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Ediacaran period (635-538ma) is a key interval in the evolution of life as it records the first macroscopic animal communities. Major extinction pulses appear to have altered the composition of the global marine biosphere between each sub-interval of the Ediacaran Period: the Avalon, White Sea, and Nama assemblage Zones. While considerable attention has been paid to the causes of these extinction pulses, less has been afforded to the consequences of Ediacaran biotic turnover for community organization and function. Moreover, it is unclear how body size - the defining trait of macrofauna - affected the transition between animal groups across …

Primates From Senèze, Eric Delson

Publications and Research

Senèze has yielded two primate fossils, neither from the recent field work. A partial ulna can be identified as cf. Macaca sylvanus. A nearly complete female skull is the holotype of Dolichopithecus arvernensis Depéret, 1928, now included in Paradolichopithecus. Emended and differential diagnoses are provided for this genus and species for the first time, and the Senèze skull is described and briefly compared to those of other species of the genus. Dental and cranial measurements are provided, along with comparative data. The macaque and Paradolichopithecus are moderately to highly terrestrial, respectively, and they suggest a woodland to more open …

An Understanding Of The Feeding Ecology Of Teleoceras Fossiger And Teleoceras Aepysoma Using Dental Microwear And Mesowear Analysis, Gabriel S. Goncalves

Master's Theses or Doctor of Nursing Practice

Teleoceras is a genus of rhinocerotids that belongs to the Tribe Teleoceratines and was widespread across North America from the late Early Miocene into the Early Pliocene. This genus was very successful, spreading across the continental United States from Florida and Tennessee to California and Washington state down to central Mexico and Honduras. Teleoceras is characterized by having a large, rounded chest cavity and short limbs with relatively high crowned teeth and lower incisors modified into tusk-like teeth. Initial ecological comparisons were made to the modern hippopotamus based on proportions of the chest cavity and its hypsodont dentition. Stable carbon …

Human Impacts On Mammal Diversity From The Pleistocene To The Present, Carson P. Hedberg

Biology ETDs

Humans have fundamentally altered the planet’s biodiversity. It is critical to characterize these changes, but also to understand how they impact the structure and function of modern ecosystems. This dissertation investigates how anthropogenically mediated species losses and/or introductions influence ecological function and community structure in mammals across multiple temporal and spatial scales. We found that selective loss of large-bodied mammals over the Late Quaternary has led to severe losses in functional diversity in modern ecosystems, suggesting megafaunal mammals contribute distinct ecological functions. These changes to mammal diversity and distribution over millennia have altered both global patterns in functional diversity and …

Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson

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

Esthonyx is an early Eocene tillodont found in North America, Europe, and India. The genus was named by Edward Drinker (E. D.) Cope in 1874 based on specimens from the San Jose Formation in New Mexico. Since then, several species of Esthonyx have been described from North America alone. The best record of Esthonyx comes from the central Bighorn Basin (BHB) in Wyoming, where it appears in 220 localities in a 640 m-thick stratigraphic succession. Since the last summary of Esthonyx in the BHB, several hundred new specimens have been collected and curated at the Denver Museum of Nature and …

Sub-Stage Climatic Shifts During Mis 11 Refined From Diatom Assemblage Reconstruction In The Valles Caldera, New Mexico, Savannah Cutler

Earth and Planetary Sciences ETDs

Diatom assemblage reconstruction from the Valles Caldera sediment core (VC-3) was utilized to infer climatic and aquatic changes during a 50-thousand-year [ka] period in the Mid-Pleistocene (435-385 ka). This 50 ka interval spans most of Marine Isotope Stage 11 (MIS 11) – one of the most prominent interglacials of the past 500 ka – and is widely considered an analog for the Holocene and future climate regimes. Nearly all records from MIS 11 are either marine or ice-core based, making VC-3 unique among lacustrine sediment records as it captures insolation variations and climatic changes during the mid-Pleistocene. Analysis of the …

Pathology And Osteological Observations Of Early Pliocene Rhinoceros, Teleoceras Aepysoma (Perissodactyla, Rhinocerotidae) From Gray Fossil Site, Tennessee, Thomas Scaife

Electronic Theses and Dissertations

Rhinoceroses were an important part of North America’s Paleogene and Neogene ecosystems, with Teleoceras aepysoma being one of the last representatives of this family. Specimens of T. aepysoma from the Gray Fossil Site (GFS) possess distinct/peculiar pathologies: including a pair of fused ribs and ankylosed phalanges. A qualitative description of the pathologies in the GFS T. aepysoma, including new material, was conducted to accurately identify pathologies and make interpretations about the life history of the GFS rhinos. Analysis suggests that rheumatoid arthritis is common in the lower limb bones of GFS rhinos. Additionally, the rib and toe pathologies are more …

Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …

Building Detailed And Accurate Whole-Plant Concepts: A Morphometrics-Informed Reconstruction Of A Zosterophyll From The Lower Devonian Of Wyoming, Samar R. El-Abdallah

Cal Poly Humboldt theses and projects

The fragmentary state of plant fossils and the modular organization of plants make whole-plant reconstructions of fossil species desirable and feasible. Such reconstructions are key for integrating fossil species in systematic studies. The ca. 410 Ma Beartooth Butte Formation of Wyoming (USA) hosts the only rich Early Devonian plant assemblages in western North America, which fills a major gap in the phytogeography of this interval. I construct a whole-plant concept for a new zosterophyll from the Beartooth Butte Formation based on a detailed morphometric study. More than 600 fragments of the new zosterophyll were observed and 200 of those were …

Celestial Bodies, Rebecca L. Rand, Mark Popinchalk

Capstones

Most of us will never come close to touching space. But space touches us every day. On Celestial Bodies, journalist Rebecca Rand and astronomer Mark Popinchalk explore the ways outer space interacts with life on earth.

In Episode 1, hosts Rebecca Rand and Mark Popinchalk explore how, for millions of years, trees have been recording celestial events in space. Within the rings of their trunks, trees store radiation from solar flares, supernovae, and changes in the earth’s magnetic field. The hosts talk to Dr. Ben Pope to learn more about what we can discover by looking at radioactive molecules …

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 …

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 …

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 …

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 …

Holocene Rice Rats (Genus Oryzomys) From The Upper Mississippi River Drainage Basin, Hugh H. Genoways

Zea E-Books Collection

The expansion and collapse of the geographic range of the Texas rice rat (Oryzomys texensis) in the upper Mississippi River drainage basin at the end of the Holocene was a unique event in North American mammals. In a period of about 4000 years with a point of origin near the American Bottom in Illinois, these small rodents extended their geographic range in a straight-line distance of over 950 km to the west into Nebraska and the same distance to the east into Pennsylvania. Then in less than 400 years this range expansion collapsed back to a point where …

New Reports Of Smilodon And Panthera From North American Cave Sites With Reviews Of Taxonomy, Biogeography, And History, Matthew Bushell

Electronic Theses and Dissertations

In this study, three new reports of large felids from the Pleistocene are presented and discussed. A single partial left dentary from Jawbone Cave represents the first confirmed presence of S. fatalis in east Tennessee and was sampled for radiocarbon dating. Wind Tunnel and Chilly Bowl Cave are among the first records of P. onca to be identified confidently from Arkansas. Chilly Bowl Cave also produced two trackways attributable to Panthera sp., one set potentially belonging to P. atrox. In addition to the description of these remains and the caves they were found in, taxonomic histories for both S. fatalis …

Reconstructing The Ecological Relationships Of The Latest Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced Diet And Ecological Niche Among Basal Ornithopod Dinosaurs, Ian Broxson

EWU Masters Thesis Collection

Of the final three connected Gondwanan landmasses, the dinosaur fossil record of Antarctica in the Cretaceous is the least complete. Most dinosaur faunas in this time period (145 Ma to 66.0 Ma) are widely separated geographically and temporally from one another by million years. However, a group of non-avian dinosaurs from the James Ross Basin (JRB) of the Antarctic Peninsula, composed of two elasmarians, a parankylosaurian ankylosaur, a hadrosaur and a suspected megaraptor, all are represented by fragmentary remains have emerged from the same horizon of the Sandwich Bluff Member (SBM) of the López de Bertodano Formation and were thus, …

The Anatomy And Phylogeny Of A New Large Plioplatecarpine Mosasaur From The Campanian Bearpaw Shale Of Montana (Usa), Richard A. Carr

Master's Theses or Doctor of Nursing Practice

In 2018, a large and associated plioplatecarpine mosasaur skull, pectoral girdle, and rib cage, whose total body length may have exceeded five meters, was uncovered in the Late Campanian Bearpaw Shale of Northeast Montana (USA). Phylogenetic analysis of this specimen, MOR 10855, recovers this individual as a basal member of the genus Plioplatecarpus. This specimen, is unique in that it is estimated to be nearly twice the size of any of the other species of Plioplatecarpus found in the Western Interior Seaway during this part of the Cretaceous. While the included phylogenetic study suggests MOR 10855 represents a new …

Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill

Master's Theses or Doctor of Nursing Practice

Avian fossil records from across the Caribbean (Greater and Lesser Antilles) demonstrate higher avian diversity prior to extinction events due to climate change at the end of the Pleistocene and human impact across the Caribbean throughout the Holocene. Amazon parrots (Amazona) are a diverse genus of New World parrots found throughout Central and South America, as well as the Caribbean. Their phylogeny and evolutionary history, specifically for Caribbean species, has been debated in terms of source areas in Central and South America and the timing of and number of colonization events to different islands that preceded diversification into …

Observations On Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) From The Campbell Plateau (Zealandia), Southwest Pacific Ocean, Kenta Abe, David M. Harwood, Richard W. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and …

Investigation Of Dead Ocean Quahogs (Arctica Islandica) Shells On The Mid-Atlantic Bight Continental Shelf, Alyssa Leclaire

Master's Theses

Ocean quahogs, Arctica islandica, are a long-lived, widely dispersed, biomass dominate in the Mid-Atlantic; therefore, quahog shells are valuable resources for studying climate change over time. Recently, dead ocean quahog shells were discovered south and inshore of the present biogeographic range of this animal. The presence of ocean quahog shells outside the current range is presumably a consequence of past regressions and transgressions of the Cold Pool, the bottom-trapped, cool body of water that allows boreal animals to live at lower latitudes. Dead ocean quahog shells were collected offshore of the DelMarVa Peninsula then radiocarbon-dated, evaluated for taphonomic condition, …

Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson

2022 Symposium

The Sandwich Bluff Formation of the James Ross Basin of Antarctica has recently yielded a group of five late Cretaceous dinosaurs that lived contemporaneously with each other, a first for Antarctica. These five dinosaurs include fragmentary remains of two differently sized elasmarian ornithopods, a possible megaraptor, a hadrosaur, and a nodosaur. In this study we will construct a model of the ecological relationships of late Cretaceous Antarctica. Additionally, we will look at what specific factors allowed this group of four herbivores and a carnivore to coexist in a restricted locality and what niches were filled by each species. Methods to …

Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin M. Schroeder

Biology ETDs

As some of the most charismatic megafauna to ever walk the earth, the physiology, morphology, growth and evolution of non-avian theropods has been studied exhaustively, yet little is understood about their roles in ecosystems as juveniles. For carnivorous megatheropods, which exceed 1,000kg in mass yet hatched from eggs of limited size, the likelihood of utilizing different prey through ontogeny was high, simply by proxy of the immense difference in size between adults and juveniles. We found these ontogenetic niche shifts, evidenced by significantly different dental microwear in Tyrannosaurids, to have excluded dinosaurian mesocarnivores from Mesozoic communities. The few dinosaurian mesocarnivores …