COLLABORATIVE RESEARCH: On Middle Miocene Biogeography and Biostratigraphy in the Northern Rocky Mountains of Idaho, Montana, and Wyoming

本项目继续研究中中新世的影响 构造作用对北方落基山脉哺乳动物地理格局的影响 山脉 该项目将测试有关 形态模式、地理模式之间的一致性 以及蒙大拿州爱达荷州中第三纪不整合面的发育 和怀俄明州。 研究将侧重于解释 地鼠类的年代学和地理分布型 （地鼠，袋鼠等）从巴斯托维沉积在5 山间盆地 Geomyoid啮齿动物是焦点，因为它们 就在不整合面之后， 开发 计算机成像和地理信息 系统技术，结合分支的方法，将被使用 分析了丰富的地质肌群的地理意义 在每个盆地中， 以及其他地区的适当比较材料， 大平原和大盆地 这项研究是广泛的 （1）确定地质和环境之间的相互作用， 在一个很少被关注的时间尺度上的生物过程 (2-3（2）应用新的古生物学技术 （成像和GIS），使我们能够解决感兴趣的问题， 古生物学家（进化，物种形成）和地质学家 （3）细化了盆地形成的联系 磁性地层学、脊椎动物生物年代学和放射性 中中新世的时间尺度，这是至关重要的， 了解北方落基山脉的构造演化。

This project continues work on the effect of middle Miocene tectonism on mammalian biogeographic patterns in the northern Rocky Mountains. The project will test hypotheses concerning the concordance between morphologic patterns, biogeographic patterns and development of the Mid-Tertiary unconformity in Idaho, Montana, and Wyoming. The study will focus on interpreting the geochronologic and biogeographic patterns of the geomyoid rodents (gophers, kangaroo rats, and such) from Barstovian deposits in 5 intermontane basins. Geomyoid rodents are the focus because they underwent a pronounced radiation just after the unconformity developed. Computerized imaging and Geographic Information System techniques, combined with a cladistic approach, will be used to analyze the biogeographic meaning of the abundant geomyoid dental remains from well-dated horizons in each of the basins, as well as appropriate comparative material from other localities in the Great Plains and Great Basin. The research is of widespread interest in (1) identifying the interplay between geologic and biotic processes on a timescale that has received little attention (2-3 million years); (2) applying new paleontological techniques (imaging and GIS) that allow us to address problems of interest to both paleontologists (evolution, speciation) and geologists (chronology of basin formation) and (3) refining links of the magnetostratigraphic, vertebrate biochronologic, and radiometric time scales in the middle Miocene, which is critical for understanding the tectonic evolution of the northern Rockies.