Paleobiology Commons^™

Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine

Geoscience Faculty Publications

Ecosystem structure—that is the species present, the functions they represent, and how those functions interact—is an important determinant of community stability. This in turn a􀀀ects how ecosystems respond to natural and anthropogenic crises, and whether species or the ecological functions that they represent are able to persist. Here we use fossil data from museum collections, literature, and the Paleobiology Database to reconstruct trophic networks of Tethyan paleocommunities fromthe Anisian and Carnian (Triassic), Bathonian (Jurassic), and Aptian (Cretaceous) stages, and compare these to a previously reconstructed trophic network from a modern Jamaican reef community. We generated model food webs consistent with …

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

Papers in the Earth and Atmospheric Sciences

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 …

Early Miocene Redwood Fossils From Inner Mongolia: Co2 Reconstructions And Paleoclimate Effects Of A Low Mongolian Plateau, Jia-Qi Liang, Qin Leng, Liang Xiao, Daianne F. Hofig, Dana L. Royer, Yi Ge Zhang, Hong Yang

Science and Technology Faculty Journal Articles

The early Miocene (~16–23 Ma) marks a critical transition in the Earth climate history from an Oligocene (~23–34 Ma) cooling trend towards the well-documented warm middle Miocene Climate Optimum at ~ 15 Ma. In eastern Asia, this transition links changes of key topographic features, such as the Tibetan plateau and the Mongolian plateau, and their impact on the reorganization of climate systems, such as the Eastern Asian summer monsoon. Yet the dynamics of the interplay among these factors remain poorly understood, precluding our understanding of future climate changes. Global temperatures during the early Miocene were warmer than the present day …

Taphonomic And Diagenetic Pathways To Protein Preservation, Part Ii: The Case Of Brachylophosaurus Canadensis Specimen Mor 2598, Paul Ullmann, Richard D. Ash, John B. Scanella

School of Earth & Environment Faculty Scholarship

Recent recoveries of peptide sequences from two Cretaceous dinosaur bones require paleontologists to rethink traditional notions about how fossilization occurs. As part of this shifting paradigm, several research groups have recently begun attempting to characterize biomolecular decay and stabilization pathways in diverse paleoenvironmental and diagenetic settings. To advance these efforts, we assessed the taphonomic and geochemical history of Brachylophosaurus canadensis specimen MOR 2598, the left femur of which was previously found to retain endogenous cells, tissues, and structural proteins. Combined stratigraphic and trace element data show that after brief fluvial transport, this articulated hind limb was buried in a sandy, …

Soft Tissue And Biomolecular Preservation In Vertebrate Fossils From Glauconitic, Shallow Marine Sediments Of The Hornerstown Formation, Edelman Fossil Park, New Jersey, Kristyn K. Voegele, Zachary Boles, Paul Ullmann, Elena R. Schroeter, Wenxia Zheng, Kenneth Lacovara

School of Earth & Environment Faculty Scholarship

Endogenous biomolecules and soft tissues are known to persist in the fossil record. To date, these discoveries derive from a limited number of preservational environments, (e.g., fluvial channels and floodplains), and fossils from less common depositional environments have been largely unexplored. We conducted paleomolecular analyses of shallow marine vertebrate fossils from the Cretaceous–Paleogene Hornerstown Formation, an 80–90% glauconitic greensand from Jean and Ric Edelman Fossil Park in Mantua Township, NJ. Twelve samples were demineralized and found to yield products morphologically consistent with vertebrate osteocytes, blood vessels, and bone matrix. Specimens from these deposits that are dark in color exhibit excellent …

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, …

Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores

Electronic Thesis and Dissertation Repository

The presence of eukaryotic life during the early Paleoproterozoic has been a matter of debate because well-preserved fossils older than 1.8 Ga rarely exhibit eukaryotic cellular microstructures. In this study, microfossils from the 1.9 Ga Gunflint Chert were studied using the extended-focal-depth imaging technique, combined with scanning electron microscopy, resulting in recognition of three types of large (10–35 μm diameter) complex unicellular bodies (CUBs) and one type of “multicellular body” (< 50 μm diameter). The CUBs show the following eukaryotic cyst-like structures: (1) radially arranged internal strands similar to those in some acritarchs and dinoflagellates; (2) regularly spaced long tubular processes, stubby pustules, and/or robust podia on the cell surface; (3) reticulate cell-wall sculpturing such as pits, ridges, and scale-like ornaments; and (4) internal bodies that may represent membrane-bounded organelles. These morphological features provide strong evidence for the presence of protists in the late Paleoproterozoic.

Among the three types of CUBs from the Gunflint microbiota, a new species, Germinosphaera gunflinta sp. nov., was recognized. This species has the diagnostic characteristics of Germinosphaera, such …

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 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 …

Pliocene Wood From The Gray Fossil Site, Owen Madsen

Undergraduate Honors Theses

The Gray Fossil Site in northeastern Tennessee preserves materials from a 5-million-year-old ecosystem, including wood from nearby trees. This study consists of three parts: conservation of wood remains, identification of taxonomic groups represented by the fossil wood, and measuring the organic content of fossil wood from the Gray Fossil Site. When excavated, wood specimens from the site are saturated due to a high local water table. After testing seven different techniques to dry wood specimens, wrapping a specimen in string and allowing it to dry slowly was the method least likely to cause warping and cracking. Microscopic examination of wood …

Rodent Dental Microwear Texture Analysis As A Proxy For Fine-Scale Paleoenvironment Reconstruction, Jenny H. E. Burgman

Graduate Theses and Dissertations

Dental microwear texture analysis (DMTA) of fossil fauna has become a valuable tool for dietary inference and paleoenvironment reconstruction. Most of this work has utilized larger taxa with larger home ranges. These studies may result in broader-scale habitat inferences that could mask the details of complex mosaic habitats. Rodent DMTA offers an opportunity to work at finer spatial scales because most species have smaller home ranges. Rodents are also keystone species within their ecosystems, abundant, ubiquitous, and found in many fossil deposits. These attributes make them excellent proxies for environmental reconstructions. However, the application of DMTA to rodents remains relatively …

Male Mastodon Landscape Use Changed With Maturation (Late Pleistocene, North America), Joshua H. Miller, Daniel C. Fisher, Brooke E. Crowley, Ross Secord, Bledar A. Konomi

Papers in the Earth and Atmospheric Sciences

Under harsh Pleistocene climates, migration and other forms of seasonally patterned landscape use were likely critical for reproductive success of mastodons (Mammut americanum) and other megafauna. However, little is known about how their geographic ranges and mobility fluctuated seasonally or changed with sexual maturity. We used a spatially explicit movement model that coupled strontium and oxygen isotopes from two serially sampled intervals (5+ adolescent years and 3+ adult years) in a male mastodon tusk to test for changes in landscape use associated with maturation and reproductive phenology. The mastodon’s early adolescent home range was geographically restricted, with no evidence of …

The Revised Systematics And Paleoecology Of The Devonian Stemless Crinoid Genus Edriocrinus Hall, 1858, Catherine E. Herbert

Theses and Dissertations--Earth and Environmental Sciences

New morphological observations of Edriocrinus Hall, 1858, enable a modern, holistic view of this unusual crinoid genus, previously included in the Superorder Flexibilia (Zittel, 1895) Wright et al., 2017. Re-analysis of Edriocrinus suggests that the genus should now be assigned to the Order ‘Dendrocrinida’ within the Magnorder Eucladida Wright, 2017 based on the five infrabasals, single radianal in the cup, absent anal sac, and non-pinnulate arms with rectangular uniserial brachials. Moreover, examination of the slight variations separating the current 14 Edriocrinus species indicates that these “species” are likely ecophenotypes. The current Edriocrinus species are revised based on firmly bound calyx …

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 …

Climate On The Blanca Massif, Sangre De Cristo Mountains, Colorado, Usa, During The Last Glacial Maximum, Keith A. Brugger, Eric M. Leonard, Kurt A. Refsnider, Peter Dolan

Geology Publications

Temperature-index modeling is used to determine the magnitude of temperature depression on the Blanca Massif, Colorado, required to maintain steady-state mass balances of nine reconstructed glaciers at their extent during the Last Glacial Maximum (LGM). The mean temperature depression thus determined is ~8.6 +0.7/−0.9 degrees C where the uncertainties account for those inherent in the glacier reconstructions, in model parameters (e.g., melt factors), and possible modest changes in LGM precipitation. Associated equilibrium-line altitudes (ELAs) exhibit a statistically significant directional dependency being lower toward the north and east. Under the assumption that regional temperature change was uniform, required changes in precipitation …

The Impacts Of Mid-Holocene Warming On Water Quality In A Southwestern Ontario Kettle Pond, Morgan E. Peicheff

Undergraduate Student Research Internships Conference

No abstract provided.

You Are What You Eat: Micro-Ct Analysis Of Early Triassic Coprolites, Olivia N. Benest

Undergraduate Student Research Internships Conference

Poster summarizing coprolite research, micro-CT analysis results, and future studies.

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …

The Sensitivity Of Neotoma To Climate Change And Biodiversity Loss Over The Late Quaternary, Catalina P. Tomé, S. Kathleen Lyons, Seth D. Newsome, Felisa A. Smith

Faculty Publications in the Biological Sciences

The late Quaternary in North America was marked by highly variable climate and considerable biodiversity loss including a megafaunal extinction event at the terminal Pleistocene. Here, we focus on changes in body size and diet in Neotoma (woodrats) in response to these ecological perturbations using the fossil record from the Edwards Plateau (Texas) across the past 20,000 years. Body mass was estimated using measurements of fossil teeth and diet was quantified using stable isotope analysis of carbon and nitrogen from fossil bone collagen. Prior to ca. 7,000 cal yr BP, maximum mass was positively correlated to precipitation and negatively correlated …

Determining Biostratigraphy And Correlation Using Color Alteration Index And Lithofacies Of Conodonts In The Edinburg Formation, Central Virginia, Lauren Showalter

Senior Honors Projects, 2020-current

Conodont species, CAI and lithofacies analysis are used as methods of correlation to determine the relative age, depositional environment, and post depositional burial history of the Edinburg Formation in central Virginia. Samples collected for conodont microfossils yielded faunas of Baltoniodus sp. or Amorphognathus sp., Periodon grandis and Protopanderodus liripipus from a site near Luray and Drepanoistodus suberectus, Plectodina sp., Protopanderodus liripipus, Oistodus sp., Phragmodus undatus, Erismodus radicans and Panderodus gracilis from a site in Harrisonburg. The species supports a Late Ordovician (Late Sandbian age). Conodonts from both sites have a CAI of 4-5, indicating post-depositional heating of …