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1	Paleobiology of a Large Mammal Community From the Late Pleistocene of Sonora, Mexico Short, Rachel A., Emmert, Laura G., Famoso, Nicholas A., Martin, Jeff M., Mead, Jim I., Swift, Sandy L., Baez, Arturo 01 July 2021 (has links) A paleontological deposit near San Clemente de Térapa represents one of the very few Rancholabrean North American Land Mammal Age sites within Sonora, Mexico. During that time, grasslands were common, and the climate included cooler and drier summers and wetter winters than currently experienced in northern Mexico. Here, we demonstrate restructuring in the mammalian community associated with environmental change over the past 40,000 years at Térapa. The fossil community has a similar number of carnivores and herbivores whereas the modern community consists mostly of carnivores. There was also a 97% decrease in mean body size (from 289 kg to 9 kg) because of the loss of megafauna. We further provide an updated review of ungulates and carnivores, recognizing two distinct morphotypes of Equus, including E. scotti and a slighter species; as well as Platygonus compressus; Camelops hesternus; Canis dirus; and Lynx rufus; and the first regional records of Palaeolama mirifica, Procyon lotor, and Smilodon cf. S. fatalis. The Térapa mammals presented here provide a more comprehensive understanding of the faunal community restructuring that occurred in northern Mexico from the late Pleistocene to present day, indicating further potential biodiversity loss with continued warming and drying of the region. carnivores community ecology conservation paleobiology mammals rancholabrean sonora ungulates
2	Optimizing Methods for Extraction of Organic Compounds from Molluscan Shells West, Kaydee Jo 22 June 2016 (has links) Mollusk shells contain proteins within and between the crystals of calcium carbonate. These organic molecules play an important role in biomineralization and shell function, and their stable isotope ratios of carbon and nitrogen are also thought to record important ecological information about the animal's diet and nutrient sources. These proteins can be preserved for millions of years, offering potential insight into pre-anthropogenic ecological conditions. However, shell organics in older shells are typically recovered in reduced abundances due to leaching and remaining organics are often converted from insoluble proteins to soluble, free amino acids, making them difficult to detect and recover. Therefore, demineralization and organics-capture methods must be optimized for yield to extract much-needed ecological information from older shells. This project compared insoluble and soluble organic yields of modern gastropod Strombus alatus shells demineralized with acids of varying concentrations and temperatures. Results suggested that demineralizing shell fragments with 0.1 M HCl at a ratio of 0.9 L HCl/g of shell was optimal. Average percent organic yields ~0.2% for modern and ~0.06% for fossil Strombus spp. Future applications of this work include using this refined method to reconstruct food webs across broad temporal scales. conservation paleobiology demineralization shell organic matrix shell demineralization methods Geology Other Ecology and Evolutionary Biology Paleontology
3	An Evaluation of Castor californicus and Implications for the Evolution and Distribution of the Genus Castor (Rodentia: Castoridae) in North America Lubbers, Kelly 01 August 2022 (has links) 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 largely within the range of variation seen within the extant species. Past distributions match fossil occurrences of Castor, suggesting confidence in projected models. Morphological and distribution similarities between the two species suggest that they can be treated as ecological analogs, though evaluation of whether they are conspecific will require more data. Beaver Castor californicus Castor canadensis Geometric Morphometrics Ecological Niche Modeling Conservation Paleobiology Paleontology
4	Utilizing the Subfossil Record of Seagrass-Associated Mollusks to Reveal Recent Changes in Coastal Marine Environments Feser, Kelsey M. 19 October 2015 (has links) No description available. Geology conservation paleobiology seagrass mollusk live dead fidelity taphonomic inertia stratigraphy
5	Extinction and Survival of Frog Crabs (Crustacea: Brachyura: Raninoida) from the Early Cretaceous to the Present Hartzell, Samantha M. 24 June 2022 (has links) No description available. Paleontology Faunal Progression Faunal Turnover Paleontology Paleobiology Conservation Paleobiology Invertebrate Evolution Crustaceans Brachyurans Crabs Decapods Podotremes Competition Diversity through time Taxon Longevity Morphology Carapace Macroevolution Extinction end-Cretaceous ArcGIS Paleo Coordinate Paleocoordinate Paleoecology

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