Collaborative Research: Understanding the Evolution of High-latitude Permo-Triassic Paleoenvironments and their Vertebrate Communities.

大约2.52亿年前，一场大规模的物种灭绝导致地球上90%以上的物种灭绝。与这次灭绝不谋而合的是，盘古超大陆的南极部分过渡到了更温暖的气候状态，没有冰川。关于南极洲物种灭绝的幸存者，人们知之甚少，尽管人们一直假设南极洲大陆？S，更极地的地理位置，保护了它免受最糟糕的物种灭绝？S的影响。沙克尔顿冰川地区是研究南极这次灭绝的最佳地点，因为它暴露了大量的正确年龄的岩石，并且在20世纪60年代和80年代在那里发现了相关的化石。在这项研究中，古生物学家将研究大约2.6亿？2.4亿年前的脊椎动物化石，以了解面对大规模气候变化时，高纬度地区的生命是如何进化的。此外，地质学家将利用化石土壤和化石植物物质来更准确地了解跨越这一灭绝边界的南极洲的气候。这些数据将使我们能够更全面地了解古代气候，以及与低纬度地区相比，南极的生活情况如何。本科生和研究生将积极参与这项研究。公众对南极科学的参与将在几个自然历史博物馆完成。这个为期三年的项目将通过在南极洲沙克尔顿冰川地区进行实地考察，研究二叠纪-三叠纪古环境及其脊椎动物群落的演变。该小组将描述沙克尔顿地区地层内的二叠纪-三叠系界线，并将其与该地区的其他地层序列进行关联(例如，通过植物有机质化石的稳定碳同位素地层学)。研究人员将使用多种类型的数据来评估古环境，包括：1)古土壤形态；2)古土壤地球化学；3)土壤有机质；4)化石木材年代学和稳定同位素。南极洲的弗雷莫组保存了整个三叠纪最高的古纬度(~70°S)四足动物群，因此有可能为揭示早中生代极地生命的演化提供重要的线索。通过对骨骼生长和象牙组织学的分析，将南极洲三叠纪脊椎动物的生物学与来自较低古纬度的同种生物进行比较。将采用跨学科的方法，在沙克尔顿冰川地区巴克利和弗赖莫夫组保存的高纬度地层的背景下，处理环境变化、动物群组成和生物地理模式之间的关系。

Around 252 million years ago, a major mass extinction wiped out upwards of 90% of species on Earth. Coincident with this extinction, the Antarctic portion of the supercontinent of Pangea transitioned to a warmer climatic regime and became devoid of glaciers. Little is known about the survivors of the extinction in Antarctica, although it has been hypothesized that the continent?s more polar location shielded it from the worst of the extinction?s effects. The Shackleton Glacier region is the best place to study this extinction in Antarctica because it exposes the correct age rocks in abundance and relevant fossils were found there in the 1960s and 1980s. For this research, paleontologists will study fossil vertebrates that span from about 260?240 million years ago to understand how life evolved at high latitudes in the face of massive climate change. In addition, geologists will use fossil soils and fossil plant matter to more precisely understand the climate of Antarctica across this extinction boundary. These data will allow for a more complete understanding of ancient climates and how Antarctic life compared to that at lower latitudes. Undergraduate and graduate students will be actively involved in this research. Public engagement in Antarctic science will be accomplished at several natural history museums.This three-year project will examine the evolution of Permo-Triassic paleoenvironments and their vertebrate communities by conducting fieldwork in the Shackleton Glacier region of Antarctica. The team will characterize the Permo-Triassic boundary within Shackleton area strata and correlate it to other stratigraphic successions in the region (e.g. via stable carbon isotope stratigraphy of fossilized plant organic matter). The researchers will use multiple types of data to assess the paleoenvironment, including: 1) paleosol morphology; 2) paleosol geochemistry; 3) pedogenic organic matter; and 4) fossil wood chronology and stable isotopes. The Fremouw Formation of Antarctica preserves the highest paleolatitude (~70° S) tetrapod fauna of the entire Triassic and thus has the potential to shed important light on the evolution of polar life during the early Mesozoic. The biology of Triassic vertebrates from Antarctica will be compared to conspecifics from lower paleolatitudes through analysis of growth in bone and tusk histology. An interdisciplinary approach will be used to address relationships between environmental change, faunal composition, and biogeographic patterns in the context of the high-latitude strata preserved in the Buckley and Fremouw formations in the Shackleton Glacier region.