Theses and Dissertations at Montana State University (MSU)

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Rural museums: harnessing the power of place to confront silences and revitalize communities
(Montana State University - Bozeman, College of Letters & Science, 2023) Moore, Sabre Addington; Co-chairs, Graduate Committee: Alex Harmon and Robert Rydell
In the United States, 43 percent of all museums are in rural towns; in Montana, rural towns account for 56.5 percent of museums. Contemporary research has neglected museums based in rural communities. While scholarship on libraries and education in rural communities thrives, there is a gap in research on rural museums. This dissertation acknowledges that gap. It explores how rural museums, like the Carter County Museum in Ekalaka, Montana, can employ the Rural Social Space Model to identify and confront the usual silences about the land and its settlement and explore the ways that power is exercised in the practices of place. Using this framework, this dissertation draws connections between the museum and the areas of environment, social well-being, and economic development, which produce rural social space and contribute to community vitality. This strategy recognizes the value of a physical place, its unique and varied histories, and the diversity of people within and connected to that place, both past and present. Rural communities have distinctive histories embedded within the culture and historical context of a broader region. Rural museums foster the experience of these histories as meaningful and personal, nurturing identity and connection to local places. As such, museums play a vital role in rural community life and provide tools to address equity challenges facing rural places. These museums regularly engage in civic work and can leverage their positions as community congregant spaces and trusted institutions to further civic action, including fostering deliberate discussion, offering volunteer opportunities, hosting public meetings, and engaging visitors in exhibits that explore the connection of past history to present action.
Bullion Creek and Sentinel Butte formations: a study of relative dating and specimen descriptions from near Cartwright, North Dakota
(Montana State University - Bozeman, College of Letters & Science, 2022) Graham, Veronica Noel; Chairperson, Graduate Committee: C. John Graves
Makenzie County in North Dakota, especially near Cartwright has not been explored by paleontologists for some time and never in great detail, yet the area is full evidence of the past. This paper focuses on the period of time between 50 and 65 million years ago when the area was believed to be a swampy sub-tropical forest skirting an inner continental seaway. It is the purpose of this paper to determine, through rock description and fossil leaf identification, the formation or formations present in this area of focus. These formations will in-turn pinpoint the time period in which the exposures were deposited. Identification of leaf impressions and molds are based on 9 key identifiers; lamina width and length, type of margin, lobation, apex and base type, apex and base angle, and vein pattern. Fossil leaf specimens can be identified to the class Magnoliopsida and other family levels, such as Taxodiaceae, Ulmaceae, Alismaceae, Betulaceae, and Sabiaceae. Additionally, some leaf specimens can be identified to the genus and species levels, including Metasequoia occidentalis, Ulmites microphylla, Alismaphyllites grandifolius, Meliosma vandaelium, and Corylus insignis. Fossils were collected on private land just outside Cartwright North Dakota where they were prepped for transport. In the lab setting they were cleaned, cataloged, and identified for the purpose of relative dating. These results demonstrate that both Sentinel Butte and Bullion Creek formations are present in the study area.
Hydrothermal influences on the Holocene environmental history of central Yellowstone National Park
(Montana State University - Bozeman, College of Letters & Science, 2020) Schiller, Christopher Michael; Chairperson, Graduate Committee: Cathy Whitlock; Cathy Whitlock, Kathryn L. Elder, Nels A. Iverson and Mark B. Abbott were co-authors of the article, 'Erroneously old radiocarbon ages from terrestrial pollen concentrates in Yellowstone Lake, Wyoming, USA' in the journal 'Radiocarbon' which is contained within this dissertation.; Rosine Cartier, Cathy Whitlock and Lisa A. Morgan were co-authors of the article, 'Multi-proxy record of Holocene paleoenvironmental conditions from Yellowstone Lake, Wyoming, USA' submitted to the journal 'Quaternary science reviews' which is contained within this dissertation.; Cathy Whitlock, Sabrina R. Brown and Petra Zahajska were co-authors of the article, 'Holocene geo-ecological evolution in Lower Geyser Basin, Yellowstone National Park' submitted to the journal 'Geological Society of America bulletin' which is contained within this dissertation.; Cathy Whitlock, Mio Alt and Lisa A. Morgan were co-authors of the article, 'Vegetation responses to Quaternary volcanic and hydrothermal disturbances in the northern Rocky Mountains and Greater Yellowstone Ecosystem' in the journal 'Palaeogeography, Palaeoclimatology, Plaeoecology' which is contained within this dissertation.
The postglacial vegetation history of Yellowstone National Park is well established by past paleoecological studies, but the role of hydrothermal activity--pervasive in areas of the park--in that history is poorly understood. To address this unknown, pollen and charcoal records were examined from lake sediment cores at multiple sites in central Yellowstone National Park to reconstruct Holocene vegetation. First, radiocarbon ages obtained from pollen concentrates were compared with other age controls at Yellowstone Lake, revealing ages that were up to 4300 cal years too old. Erroneous ages were due to either old carbon contamination from magmatic or hydrothermally degassed CO 2 or old pollen reworked from an unknown source. Second, Holocene vegetation and fire history were reconstructed from a Yellowstone Lake sediment core. The record was characterized by gradually increasing closure or extent of Pinus contorta forest and increasing fire activity to the present, consistent with reduced summer insolation creating cooler, effectively wetter conditions in central Yellowstone National Park. No impact of hydrothermal activity was detected in the regional Holocene-long vegetation and fire histories. Third, Holocene vegetation and fire history were studied at Goose Lake in Lower Geyser Basin, an area with abundant modern hydrothermal activity. The vegetation and fire history diverged from the regional trend at 3800 cal yr BP, synchronous with geochemical indicators indicating reorganization of hydrothermal activity in the basin, suggesting an abrupt ecological response to shifting hydrothermal activity. Finally, a variety of volcanic and hydrothermal processes were investigated as disturbances in the Northern Rocky Mountains and Yellowstone National Park through high-resolution pollen analysis. Hydrothermal explosion deposits were found to be synchronous with conifer morality, in some records, indicating that the effects of hydrothermal explosions are local and short-lived. At a regional scale, it is evident that vegetation changes were chiefly responding to millennial-scale, insolation-driven climate change. However, the impacts of hydrothermal activity were locally important where pervasive, as in Lower Geyser Basin, and in areas recently affected by hydrothermal explosions.
Late Holocene vegetation and fire history in subalpine forests of northwestern Montana
(Montana State University - Bozeman, College of Letters & Science, 2020) Sly, Shelby Fulton; Chairperson, Graduate Committee: David McWethy
Mid-to high- elevation forests of the Northern Rocky Mountains are dynamic systems that change in time in response to climate, disturbance and human activities. Climate models suggest these ecosystems will experience warmer temperatures, decreased spring snowpack, drier summers, and longer fire seasons, highlighting a need to better understand how these systems respond to changing climatic conditions. Sediment cores were extracted from two lakes in the Mission and Reservation Divide Mountains of Montana and analyzed for pollen and macroscopic charcoal to reconstruct fire and vegetation histories. The records from Mud Lake and Three Lakes Peak span the last 5400 and 4600 years respectively, and highlight the long-term persistence and relative stability of closed, mixed conifer/subalpine forests. During the mid-Holocene (approx. ca. 5000 yr BP), Pinus pollen percentages increased, suggesting closed forests which then transitioned to mesic forest of Pinus, Abies, and Picea over the last ca. 4000 years. Modern forests established between 3500-3000 cal yr BP at both sites. Both sites experience elevated fire activity during the Medieval Climate Anomaly c. 1000-900 cal yr BP which is consistent with other sites in the region. While relatively infrequent (2-4 fires per millennia), wildfires played a role in maintaining early successional vegetation (Poaeceae, Alnus spp.) and taxa that benefit from post-fire reduction in competition such as five-needle pines. Paleoenvironmental records from these two sites indicate subalpine forests of northwestern Montana persisted with relative stability throughout the mid to late-Holocene. With projections for increased warming, longer fire seasons and the possibility for increased occurance of short-interval fires in higher elevation ecosystems of the Northern Rocky Mountains, subalpine forests may become vulnerable to rapid transitions to different forest types or even non-forest systems.
Understanding the present and past climate-fire-vegetation dynamics of southern South America (40 - 45°S)
(Montana State University - Bozeman, College of Letters & Science, 2020) Ogunkoya, Ayodele Gilbert; Chairperson, Graduate Committee: Benjamin Poulter; David Roberts (co-chair); Jed O. Kaplan, Cathy Whitlock, William Nanavati, Benjamin Poulter and David Roberts were co-authors of the article, 'Drivers of modeled forest cover change in southern South America are linked to climate and CO^2' which is contained within this thesis.; Jed O. Kaplan, Cathy Whitlock, William Nanavati, Benjamin Poulter, David Roberts and Steve Hostetler were co-authors of the article, 'Climate drivers of late-glacial to postgalacial forest cover along the eastern Andes of Northern Patagonia (lat. 40 - 45°S)' which is contained within this thesis.
The forest-steppe boundary that runs north-to-south along the eastern Andes is particularly dynamic over millennial time scales. Yet the relative role of long-term climate change and fire is poorly understood. In this study, I analyze the potential in using a process-based model in predicting species distribution, and the role fire and climate played in shaping the vegetation and treeline dynamics of Northern Patagonia (lat. 40 - 45 ° S). Paleoecological data, e.g., pollen, has been extensively used to study the relationship between climate and vegetation but has a low spatial resolution to distinguished between climate-fire-vegetation dynamics. Process-based model thus offers a transparent and robust method of incorporating a varying degree of complexity to understand fire behavior and fire-vegetation dynamics. Recently, LPJ-GUESS was parameterized to simulate major regional plant functional type (PFTs) and tree species distributions in this region. The model is able to predict regional species distribution across spatial scales by coupling establishment, growth, and mortality processes. Predicting spatial and temporal scale species distribution cannot be achieved without having the right climate and soil data, the climate data used was downscaled from 50 km to 1 km resolution using Worldclim climate data ( ~ 1 km) as the reference data. LPJ-GUESS model produced regional species distribution with fair to very good agreement with observation. The optimization of bioclimatic parameters and drought tolerance that is related to root depth, adaptability of plant to seasonal drought, and movement of nutrients consistently improved the accuracy of regional prediction of the species range. The model predicted that the vegetation distribution of present-day is mainly determined by climate and CO 2 rather than fire., while forest productivity responds strongly to elevated CO 2. However, based on the employed statistical methods of Canonical Correspondence Analysis (CCA) and Random Forest machine learning, combined with simulation results using paleoclimate. Results show that an increase in winter temperature drives the postglacial species distribution while changes in precipitation control radial growth and seedling establishment in the upper and lower treeline. These findings emphasize the importance of combining paleoecological methods with modeling to disentangle coarse-scale climate drivers from local influences.
An analysis of fossil identification guides to improve data reporting in citizen science programs
(Montana State University - Bozeman, College of Letters & Science, 2018) Butler, Dava; Chairperson, Graduate Committee: Greg Francis
An increasing number of organizations use untrained volunteers to gather scientific data. This citizen science movement builds enthusiasm for science by engaging the public, as well as providing a way to gather large amounts of information at little or no expense. The challenge of citizen science is obtaining accurate information from participants. Identifying an image style that increases correct identifications helps not only the citizen science movement but also scientific instruction in general. This study tests three visual guides for identifying late Hemphillian (5-4.5 m.y.a.) fossils from Polk County, Florida. Each guide has identical layout and text, differing only in image style: color photos, grayscale photos, or illustrations. Teams of untrained participants each use one guide to identify fossils. Geology and paleontology professionals also identify fossils for comparison. Comparing results reveals that photographic images, either color or grayscale, produce results most similar to data from professionals.
Field science experiences in paleontology: shaping science stewardship in high school learners
(Montana State University - Bozeman, College of Letters & Science, 2019) Lepore, Taormina Jean; Chairperson, Graduate Committee: Greg Francis
How do field science experiences shape a sense of conservation and stewardship in learners? This study analyzed separate groups of female-identifying and male-identifying 9th grade high school students (N=80) on their first field paleontology experience at Rainbow Basin Natural Area, California. Likert-style surveys and written self-reflections indicate relative consistency in pre- and post-treatment responses student-to-student, through when paired with qualitative responses, the power of science stewardship and a personal sense of connection to public lands becomes markedly apparent. Future studies in the realm of science stewardship in field paleontology will help illuminate the impact of field paleontology on science learners.
Late Holocene climate, fire, and vegetation history on the northern range, Yellowstone National Park
(Montana State University - Bozeman, College of Letters & Science, 2019) Firmage, David Samuel; Chairperson, Graduate Committee: Cathy Whitlock
Yellowstone National Park is an iconic natural landscape that encompasses unique geologic features as well as a diverse and ecologically important flora and fauna. The ecological resilience of the Northern Range of the park, home to the park's ungulate herds, faces an uncertain future with a projected warming climate over the next century. Understanding the variability of vegetation organization in response to past changes in climate can help park managers plan for future climate scenarios. Lake sediment cores from two lakes were collected, analyzed for pollen type, charcoal accumulation and lithological components, and compared with other studies to highlight commonalities in fire-histories and vegetation trends across the Northern Range over the past 4000 cal yr BP. Foster Lake the records suggest fire-episodes and changes to lake productivity and between ~3500-2900 cal yr BP, large intense fire-episodes between ~2500-2150 cal yr BP, ~1000 cal yr BP and frequent large fire episodes from ~700 cal yr BP to the present day. Floating Island Lake records between ~4000-3000 cal yr BP suggest the site experienced infrequent, large fire episodes concurrent with periods of protracted drought and decreases in water level. Between ~3000-1500 low intensity fire episodes were common, punctuated by infrequent large fire episodes at ~2900, ~2250, ~2050 and ~1880 cal yr BP. During the last ~1ka two fire episodes were recorded at Floating Island Lake, at ~1030 cal yr BP coincident with the Medieval Climate Anomaly, and 270~ cal yr BP during the Little Ice Age. A comparison of fire histories from studies spanning the Northern Range shows that during periods of protracted drought large fire episodes are common across the landscape, and that during periods of moderate climate fire size and severity is likely modulated by local site controls such as topography and vegetation structure. This study shows that fire episodes in the Northern Range have occurred as a spatial and temporal mosaic, and are likely to continue to do so. Additionally, this study increases our understanding of how vegetation structure and fire regimes in the Northern Range have varied as a result of a range of climate conditions in the past. Such baseline information helps us anticipate some of the ecological responses that may occur in the decades ahead with global warming.
Osteology, phylogeny, taphonomy, and ontogenetic histology of Oryctodromeus cubicularis, from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho
(Montana State University - Bozeman, College of Letters & Science, 2017) Krumenacker, L. J.; Chairperson, Graduate Committee: David Varricchio; David J. Varricchio, Chris Organ, Clint Boyd and Brooks Britt were co-authors of the article, 'Osteology and phylogeny of the neornithischian dinosaur Oryctodromeus cubicularis from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho' submitted to the journal 'Journal of vertebrate paleontology' which is contained within this thesis.; David J. Varricchio, John Wilson and Ashley Ferguson were co-authors of the article, 'Taphonomy of Oryctodromeus cubicularis from the mid-Cretaceous (Albian-Cenomanian) of Idaho, and additional Oryctodromeus burrows from Idaho and Montana' submitted to the journal 'Palaeogeography, palaeoclimatology, palaeoecology' which is contained within this thesis.; David J. Varricchio, John R. Horner and Kelli Taddy were co-authors of the article, 'Ontogenetic histology and growth of the neornithischian dinosaur Oryctodromeus cubicularis from the middle Cretaceous (Albian-Cenomanian) of Montana and Idaho' submitted to the journal 'Journal of vertebrate paleontology' which is contained within this thesis.
Oryctodromeus is a small bipedal dinosaur known from middle Cretaceous (95-100 My) Wayan Formation of Idaho and the Vaughn Member of the Blackleaf Formation of Montana. This taxon is hypothesized to be a burrowing dinosaur, which cared for its young within these burrows. This dissertation is a broad three-part treatment of this taxon, and excepting the introductory and concluding chapters this dissertation consists of three main chapters. Chapter two describes the osteology and phylogenetic relationships of this animal. Notable features of the Oryctodromeus skeleton described include a network of ossified tendons along the vertebral column that completely ensheath the tail, a long tail that forms more than half the length of the animal, and unusual femoral heads whose morphology may be related to burrowing behavior. The first full skeletal and skull reconstructions of this animal are presented. Chapter three investigates patterns of preservation of Oryctodromeus. Data suggests that preservation of single to multiple individuals of this taxon typically occurred in burrows that may be difficult to impossible to recognize in the fossil record. New examples of burrows from Oryctodromeus from the Vaughn and Wayan, as well as additional evidence for social behavior, are also described. A third chapter details the ontogenetic histology, growth rates and patterns of skeletal fusion based on seven limb elements (femora and tibiae) from different individuals. Based on the data in this dissertation, three growth stages can be recognized in Oryctodromeus based on bone histology. Juveniles are defined by more rapidly growing fibrolamellar tissue, sub-adults are defined by a cortex of inner fibrolamellar tissue and outer zonal parallel fibered tissue, and near-adult individuals have tissue similar to sub adults with dense avascular bone in the outermost cortex that signals a decrease in growth rate. LAG's suggest a minimum age of six to seven years for more mature individuals. Patterns of neurocentral fusion in Oryctodromeus appear similar to those of crocodylians and some other small ornithischians, while the growth rates of Oryctodromeus appear slower than those of some dinosaurs, but similar to taxa such as Orodromeus and Tenontosaurus.
Description and ontogenetic assessment of a new Jehol microraptorine
(Montana State University - Bozeman, College of Letters & Science, 2014) Poust, Ashley William; Chairperson, Graduate Committee: David Varricchio
Fossils from the Jehol Group (Early Cretaceous, Liaoning Province, China) have greatly contributed to our understanding of the morphology and diversity of Paraves, the group of dinosaurs including sickle-clawed dromaeosaurs, large-brained troodontids, and avialians, the ancestors of modern birds. However, many taxa are represented by only a few specimens of unclear ontogenetic age. Without a thorough understanding of ontogeny, the evolutionary relationships and significance of character states may be obscured within paravian dinosaurs. A complete specimen of a new taxon of microraptorine dromaeosaur, Wulong bohaiensis gen. et sp. nov., from the Jiufotang Formation (upper Jehol Group) exhibits clearly juvenile morphology. The dinosaur is small and preserved in articulation on a single slab. It has microraptorine features such as a subarctometatarsalian foot, a short first manual digit, and a prominent tubercle on the pubis. Phylogenetic analysis substantiates this assignment. It also possesses more than 29 tail vertebrae, inclined pneumatic foramina on its dorsal vertebrae, and an unusually large coracoid fenestra, which with other features argue that it is a new taxon. This individual shows many osteological markers of immaturity identified in other archosaurs. Skull elements, all visible neurocentral sutures, pubes, and proximal tarsals remain unfused. Grainy surface texture of the cortical bone and poor ossification of long bone articular surfaces further supports an immature status. Histologic samples of the tibia, fibula, and humerus of this individual (the first microraptorine theropod to be sampled) confirm that it was around a single year in age and still growing at death, but that the growth had slowed. This slow down in growth is interesting in light of the presence of pennaceous feathers extending from the fore- and hind-limbs and, notably, two long plumes extending more than 12 cm from the tip of the caudal series. This indicates that presence of a variety of feather types, including filamentous feathers, pennaceous primaries, and long rectrices, likely used for ornamentation, preceded skeletal maturity and full adult size.

Theses and Dissertations at Montana State University (MSU)

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