Congratulations to the following 2012 Evolving Earth Student Grant recipients:
Balbas, Andrea
Oregon State University
“Testing variations in cosmogenic-nuclide production rates through the Matuyama-Brunhes magnetic reversal”
We propose to evaluate the effects of the M-B reversal on the flux of cosmic radiation as reconstructed from in situ CN 3He concentrations measured from well-dated basalts that span the reversal. Previous research on an Antarctic ice core defined a signature of enhanced cosmogenic 10Be concentrations associated with the reversal. Although this is an atmospheric signal and not an in situ signal, it is a significant indicator of increased cosmic ray activity associated with field strength reduction. The flux of cosmic radiation during geomagnetic reversals should be even greater at low latitudes, where the field is most efficient in shielding the secondary cosmic rays, but a record of such a relationship has yet to be defined. We propose to define this record by analyzing several basalt layers that record both the paleomagnetic and CN signatures before, during, and after the M-B reversal. Here we propose a strategy to define the effects of such an event of paleo-production rates.
Berg, Lauren
University of Washington
“An Integrative Assessment of Locomotion and Body Size Patterns in Mammals Across the Cretaceous-Paleogene Mass Extinction Boundary”
The Hell Creek and Tullock Formations in northeastern Montana preserve the Cretaceous-Paleogene (K-Pg) Mass Extinction event and provide the ideal place to study mass extinction and recovery dynamics, ecological restructuring, and morphological diversification in a stratigraphically, temporally, and geographically constrained framework. Notwithstanding an abundance of data derived from mammalian dental specimens, little remains known about the paleoecology of mammals respect to locomotor patterns at this time period. I propose to study known postcranial elements from Cretaceous and Paleogene deposits in eastern Montana and apply geometric morphometric methods to quantify shape diversity and disparity across the mass extinction boundary. Fieldwork funding requested during this phase (late June – August 2012) will facilitate acquisition of additional specimens for study, as well as assessment of depositional environment and taphonomy in my sampling.
Hatala, Kevin G.
The George Washington University
“A snapshot of the anatomy, locomotion, and social behavior of early modern humans as evidenced by fossil footprints at Engare Sero, Tanzania”
This project is focused on the excavation and analysis of a new fossil human footprint site at Engare Sero, Tanzania. This site preserves over 350 fossil human footprints and dates to about 120 ka, making it the oldest substantial assemblage of early modern human (>100 ka) footprints known in the world. The exceptional preservation of these footprints will allow us to 1) analyze their 3D topography to determine whether or not the anatomy and gait of these early humans were similar to those of contemporary habitually unshod humans, 2) develop hypothesis about group composition in a sample of early modern humans traveling across the landscape at a moment in time around 120 ka, and 3) frame hypotheses about the evolution of modern human anatomy and behavior in an immediate ecological context.
McAdams, Neo E. Buenger
University of Iowa
“Sampling, imaging, unrevealed data, and phylogeny: What are we missing and what are the consequences?”
Systematic and applied studies of invertebrates depend on images because detailed observation of surface morphology is only possible in grayscale images of specimens that have been made opaque and usually also magnified. New developments in digital imaging and electronic publication, coupled with intensive field sampling, permit a new paradigm for documentation of fossil species. Lower Ordovician trilobites, examined from literature and from new sampling, provide excellent test cases to explore how insufficient sampling and low standards of illustration create poorly known species with unnecessarily missing morphological and phylogenetic data. Accurate progress in paleontology is impossible without a basis of solid taxonomy and phylogenetic systematic based on large sample sizes and maximally informative illustrations. This project seeks to quantify the effects of organismal completeness, sampling, and illustration on systematic and reconstruction of phylogenetic relationships, by analyzing phylogenetic matrices coded from differing qualities of information.
McLaughlin, Win
University of Oregon
“Paleontological exploration of the fauna and flora of Hawk Rim, OR”
Hawk Rim represents a new middle Miocene locality in Eastern Oregon. Containing a diverse vertebrate fauna and flora deposits, Hawk Rim is reconstructed as a lush wooded habitat, near lakes and rivers. Filling a geographical gap between several other Oregonian Mid-Miocene sites, Hawk Rim facilitates the study of changing ecosystems across the space and deep time. The complex heterogeneity of Oregon’s fossil record is underscored by the presence of new species, and the first occurrence of species in the state or Northwest. Description of this site stratigraphy and fossils facilitates a better understanding of the Northwest geological and evolutionary past.
Pritchard, Adam
Stony Brook University
“The early evolution and radiation of saurian reptiles”
This project proposes the development of a novel, well-supported phylogeny for Sauria, the reptile clade included Lepidosauromorpha (lizards and snakes) and Archosauromorpha (crocodiles and birds). The study will resolve the phylogenetic relationships and positions of many bizarre Permian and Triassic reptiles. The funding requested will go largely to museum travel, so as to develop an extensive record (photographic and otherwise) of as many relevant taxa as possible. The final phylogeny will create a new dimension to understanding biogeography, evolutionary change rates, and the Pangaean ecosystem following the Permo-Triassic extinction event.
Scannella, John
Museum of the Rockies, Inc.
“Evolutionary and developmental trends in the ceratopsid dinosaur Triceratops from the Cretaceous Hell Creek Formation, Montana”
Recent exploration of the Cretaceous Hell Creek Formation (HCF) has produced ontogenetic series of the famous ceratopsid dinosaur Triceratops from the middle and upper units of the formation, however the record from the lower unit is largely incomplete. This project involves returning to the lower HCF to reassess Triceratops which were discovered but uncollected in the past, and also to find new specimens. These specimens will fill a critical gap in the stratigraphic record of this genus and contribute to the completion of a growth series of Triceratops from the lower unit. Comparisons of growth series from different stratigraphic zones will allow for a detailed study of dinosaur heterochrony and provide a test for hypotheses on the modes of dinosaur evolution.
Smith, Kimberly
University of Washington
“Vegetation reconstruction of Southwest Montana during the Miocene using phytolith analysis”
This project uses plant silica microfossils (phytoliths) to look at the response of vegetation communities in Montana to the Middle-Miocene Climatic Optimum (MMCO) which occurred 15 million years ago. Plant macrofossils from the MMCO in North America are rare, but phytoliths are abundant and well preserved in fossil soils. Polled Herefords in a site in Southwest Montana with outcropping continuous, phytolith rich lithologies that span the MMCO. Assemblages are currently being analyzed, and preliminary results show vegetation communities indicating a warm, wet climate. More samples will be collected this summer to increase the spatial and temporal resolution of the study and provide a more complete picture of the changes in vegetation communities. Understanding these changes will help us predict the shifts that will happen in modern vegetation due to the current climate change.
Tremblay, Susan
The Regents of the University of California
“Insights into liverwort character evolution from new discoveries in the fossil record”
The goal of this project is to elucidate character evolution in the liverworts, the earliest diverging lineage of land plants. This will be done through collection and analyses of Devonian liverwort fossils from new localities in the Catskill region of Eastern New York State. The well-preserved fossils will be isolated from the shale matrix by HF acid maceration. The analyses will include electron microscopy of hypothesized conducting tissues for comparison with modern liverworts and chemical and statistical tests of the homology of scattered dark cells of the fossil liverworts with oil cells of extant taxa. These Devonian fossils, along with all Paleozoic and Mesozoic liverwort taxa will be incorporated into a recent phylogeny of the liverwort clade.
Yann, Lindsey
Vanderbilt University, EES
“Effects of climate change on camelids and mammalian communities through time: Integrating paleontological and ecological records”
Extant members of Camelidae, including vicunas and guanacos, are adapted to some of the most arid places on Earth; however, it is unclear how they evolved from forest browsing camelids into arid adapted taxa. To better understand extant camelids, we plan to quantify how the presence/absence of other camelids and sympatric taxa impact the dietary breadth of Pleistocene camelids. We hypothesize that dietary niches are not conserved through time; instead, the presence of two genera within the same family causes increased dietary niche partitioning. We have selected seven sites across the United States with differing abundances of Pleistocene camelids, and the dietary breadth of taxa present at each site will be determined using carbon isotopes. Pleistocene camelids will then be compared to modern vicunas and guanacos, clarifying how camelid dietary niches have changed through time.