Paleobiology and Taphonomy of Exceptional Preserved Fossils from Jurassic Lacustrine Deposits, Beardmore Glacier Area and Southern Victoria Land, Antarctica

该奖项由极地方案办公室南极地质学和地球物理学方案提供，支持对南极洲横贯南极山脉比尔德摩尔冰川区和维多利亚地南部费拉群（侏罗纪）柯克帕特里克玄武岩湖相夹层中的生物化石进行古生物学和埋藏学（死后历史）研究。柯克帕特里克玄武岩的沉积夹层代表了特殊保存（或Konservat-Lagerstatten）的不寻常矿床，其特征是存在各种非生物矿化（或所谓的软体）生物。在过去的几十年里，野外工作发现了大量的叶肢介类（具有非矿化外骨骼的双瓣节肢动物）和鱼类的遗骸，各种节肢动物如昆虫，syncarids和等足类动物的遗骸较少，以及植物碎片。节肢动物和鱼类化石的质量范围从脱节的碎片到有关节的遗骸，可与化石记录中已知的最好的化石相媲美。湖相沉积物的重新收集应产生额外的异常保存的化石，可能包括额外的分类群，和其他重要的古生态，埋藏和古环境解释的数据。目前的迹象表明，柯克帕特里克湖沉积物提供了重要的“窗口”的高纬度，中生代中期的淡水生态系统的演化历史。对柯克帕特里克湖沉积物的古生态学和埋藏学研究有望提供额外的线索，以了解地质历史中非矿化骨骼部分（或许还有软质部分）异常保存的一般条件。这一点很重要，因为我们目前对异常保存条件的理解几乎都来自对海洋沉积物、边缘海洋沉积物或低至中古纬度淡水沉积物的研究。本研究的主要目的是：（1）收集和系统地记录南极洲比尔德莫尔冰川区和维多利亚地南部柯克帕特里克玄武岩遗址沉积夹层中的生物群，（2）记录和解释柯克帕特里克遗址的埋藏学信息，包括化石的成岩蚀变，（3）描述和解释与身体化石有关的遗迹化石，（4）研究与身体化石有关的生物群。（4）记录和解释柯克帕特里克遗址异常保存的地层学和沉积学背景。这项研究的完成将使我们对中生代中期高纬度湖泊生态系统的生物群和古生态学有更全面的了解。该柯克帕特里克网站将提供有用的信息，在全球范围内解释侏罗纪生物化石，因为它将提供一个更好的基础，比较更有名的，低到中纬度的存款异常保存。从柯克帕特里克存款的研究数据预计将提供有关的基本问题，为什么特殊的保存生物发生在淡水，高纬度设置的信息。

This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a study of the paleobiology and taphonomy (postmortem history) of biotas from lacustrine interbeds within the Kirkpatrick Basalt of the Ferrar Group (Jurassic), Beardmore Glacier area and southern Victoria Land, Transantarctic Mountains, Antarctica. Sedimentary interbeds of the Kirkpatrick Basalt represent unusual deposits of exceptional preservation (or Konservat-Lagerstatten), characterized by the presence of a variety of non-biomineralizing (or so-called soft-bodied) organisms. Fieldwork in previous decades resulted in discovery of abundant remains of conchostracans (bivalved arthropods having non-mineralized exoskeletons) and fishes, less common remains of various arthropods such as insects, syncarids, and isopods, as well as plant fragments. The arthropod and fish fossils range in preservational quality from disarticulated pieces to articulated remains comparable to the finest known from the fossil record. Renewed collecting of the lacustrine deposits should yield additional exceptionally preserved fossils, possibly including additional taxa, and other data important for paleoecologic, taphonomic, and paleoenvironmental interpretation. Present indications are that the Kirkpatrick lake deposits offer important "windows" into the evolutionary history of high-latitude, freshwater ecosystems of the middle Mesozoic. Paleoecologic and taphonomic study of the Kirkpatrick lake deposits can be expected to provide additional clues to the general conditions under which exceptional preservation of non-mineralized skeletal parts, and perhaps soft parts, occurred in the geologic past. This is significant because nearly all of our current understanding of conditions surrounding exceptional preservation has been derived from studies of marine deposits, marginal-marine deposits, or freshwater deposits from low- to middle-paleolatitudes. Principal objectives of the research are: 1) to collect and systematically document the biota of the sedimentary interbeds of the Kirkpatrick Basalt sites in the Beardmore Glacier area and southern Victoria Land, Antarctica; 2) to document and interpret taphonomic information on the Kirkpatrick sites, including diagenetic alteration of fossils; 3) to describe and interpret trace fossils that are associated with the body fossils; and 4) to document and interpret the stratigraphic and sedimentologic context of exceptional preservation in the Kirkpatrick sites.Considerable importance attaches to the Jurassic sites in the Transantarctic Mountains area because few sites from aqueous ecosystems of high paleolatitude areas are known to contain non-biomineralized fossils. Completion of this study will result in a more complete understanding of the biota and paleoecology of high latitude lacustrine ecosystems of the middle Mesozoic. The Kirkpatrick sites will provide information useful for interpreting Jurassic biotas in a global context, as it will provide an improved basis for comparison with better-known, low- to middle-latitude deposits of exceptional preservation. Data from study of the Kirkpatrick deposits are expected to provide information concerning the fundamental question of why exceptional preservation of organisms has occurred in freshwater, high latitude settings.