SGER: Timely Excavation of an Upper Cretaceous Fossil-Lagerstatte, Eastern Alabama

及时发掘阿拉巴马州东部上白垩统的拉格斯塔特化石查尔斯·E·萨夫达和罗纳德·D·刘易斯·奥本大学EAR-0633839摘要英格索尔页岩是一种薄的(~1米)不连续的粘土透镜体，位于阿拉巴马州菲尼克斯市附近私人地产的山坡上，位于上白垩统的尤陶组内。自2003年底首次发现以来，对这一边缘海相沉积物的小规模挖掘已经产生了异常丰富和保存完好的化石组合。因此，它是一个保护性化石的例子-lagerstatten，一个保存异常完好的化石的沉积物。该生物群包括由植物大化石、大孢子和孢粉(包括海洋甲藻)组成的多样化的植物区系，丰富的琥珀，以及包括软体动物、节肢动物和脊椎动物的动物群。尽管许多化石是碳化的和/或黄铁矿的，但组合中的某些元素反映了蛋白质(例如，胶原和角蛋白)的异常保存。这些蛋白质化石包括羽毛，这在化石记录的这一部分是极其罕见的。在短时间内，由于业主正在进行的住房开发，曝光将被销毁。NSF的资助使该遗址的挖掘能够在这一重要的科学资源仍然可用的情况下以快速和专业的方式完成。像其他拉格斯塔滕一样，英格索尔页岩的特殊保存具有对古生物学做出重大贡献的潜力，并澄清了稀有化石的保存条件。关于生物群本身，英格索尔页岩中发现的植物群丰富多样。仅从化石叶子就已经识别出20多个属的植物，其中一些似乎基本上没有改变。这些可以从岩石上剥离，并且仍然有一定的弹性。种子和球果等植物生殖体通过黄铁矿化和碳化得到三维保存。琥珀通常出现在英格索尔页岩中的一些地层中，一些琥珀样本发现了昆虫和螨虫的遗骸。一些未压缩的植物大型化石中含有原位琥珀杆；因此，存在识别琥珀生产者和在群落内建立植物-昆虫关联的难得机会。英格索尔页岩中发现的羽毛标本具有特殊的古生物学意义。除了来自辽宁省的壮观的有羽毛的恐龙中国外，羽毛是中生代极其稀有的化石。已知的矿点通常只由一个或几个孤立的个体组成，而英格索尔页岩已经产生了三个样本。由于琥珀已被证明是保存羽毛细节最好的介质，因此有可能找到保存极为完好的标本。此外，其他以角蛋白为基础的组织，如喙和爪子/爪，以及羽毛携带者的胶原性结缔组织也可以保留。鉴于蛋白质化石成分的保存状况，进一步的挖掘有望发现软体遗骸，包括有羽毛的兽脚类等脊椎动物的遗骸。

TIMELY EXCAVATION OF AN UPPER CRETACEOUS FOSSIL-LAGERSTATTE, EASTERN ALABAMAbyCharles E. Savrda and Ronald D. LewisAuburn UniversityEAR-0633839ABSTRACTThe Ingersoll shale is a thin (~1 m), discontinuous clay lens within the Upper Cretaceous Eutaw Formation exposed on a hillslope on private property near Phenix City, Alabama. Since its initial discovery in late 2003, small-scale excavation of this marginal marine deposit has yielded an extraordinarily rich and well-preserved fossil assemblage. Thus, it is an example of a conservation fossil- lagerstatten, a deposit with unusually well-preserved fossils. The biota includes a diverse flora consisting of plant macrofossils, megaspores, and palynomorphs (including marine dinoflagellates), abundant amber, and a fauna that includes mollusks, arthropods, and vertebrates. Although many of the fossils are carbonized and/or pyritized, certain elements of the assemblage reflect unusual preservation of proteins (e.g., collagen and keratin). These proteinaceous fossils include feathers, which are extremely rare in this part of the fossil record. Within a short time, the exposure will be destroyed as a result of the ongoing housing development by the property owner. NSF funding is allowing excavation of the site to be completed in a rapid and professional manner while this important scientific resource is still available.Like other Lagerstatten, the exceptional preservation of the Ingersoll shale has the potential of making significant contributions to paleobiology and clarifying the conditions under which rare fossils are preserved. With regard to the biota itself, the flora found in the Ingersoll shale is abundant and diverse. Over two dozen genera of plants have been recognized from fossil leaves alone, some of which appear to be essentially unaltered. These can be peeled from the rock and are still somewhat flexible. Plant reproductive bodies such as seeds and cones are preserved three-dimensionally by pyritization and carbonization. Amber occurs commonly in some horizons within the Ingersoll shale, and some amber samples have yielded remains of insects and mites. Some uncompacted plant macrofossils contain in situ amber rods within them; thus, the rare opportunity exists of identifying the amber-producers and establishing plant-insect associations within a community. The feather specimens found in the Ingersoll shale are of particular paleobiological significance. Aside from the spectacular feathered dinosaurs from the Liaoning Province, China, feathers are extremely rare fossils in the Mesozoic. Known occurrences often consist of only one or a few isolated individuals, whereas the Ingersoll shale has already produced three specimens. Because amber has been shown to be the best medium for preserving feathers in detail, the possibility exists of finding extremely well-preserved specimens. Furthermore, other keratin-based tissues, such as beaks and claws/talons as well as collagenous connective tissue of the feather bearers could be preserved. Given the state of preservation of proteinaceous fossil components, further excavation holds promise for discovery of soft-bodied remains, including that of vertebrates such as feathered theropods.