Early History of Horned and Duck-billed Dinosaurs: Discoveries in Gansu, China

角和鸭嘴恐龙的早期历史：甘肃的发现 Pi Peter Dodson宾夕法尼亚大学合作研究者尤海璐中国地质科学院北京合作研究者 李大庆甘肃省地质矿产勘查开发局第三地质矿产勘查院化石研究开发中心 徐星，北京古脊椎动物与古人类研究所摘要20年前，中国是世界上第三大恐龙发源地，仅次于美国和蒙古。自1996年以来，中国在辽宁、山东、河南、内蒙古、甘肃和新疆等地相继发现了鸟类和非鸟类恐龙化石，使中国的恐龙多样性居世界首位。中国已经培养了一批新的年轻研究人员，他们对共同丰富的联合奖学金持开放态度。中国西北部的甘肃省已被证明是一个丰富的来源，丰富和保存完好的恐龙化石在一个关键的时间间隔，早白垩世。高质量的化石仅在1997年才在甘肃被描述出来。仅2009年就发现了4个新属。我们建议在甘肃的化石层中取样，跨越早白垩世的一个广泛的间隔，以详尽地记录从更基础的草食恐龙到更衍生的恐龙的关键进化过渡。在北方晚白垩世动物群中占主导地位的、高度演化的鸭嘴龙-角龙类动物群起源于早白垩世的关键时期，当时，古老的中生代蕨类植物-苏铁植物-针叶植物为主的植物群开始向现代被子植物为主的植物群转变。甘肃西北部早白垩世新民铺群晚期沉积物中含有丰富的食草恐龙化石。角龙类和鸟脚类化石都比辽宁早白垩世中期热河动物群演化程度更高。该项目包括五个明确的目标：1）发现更多的角和鸭嘴恐龙，并在其地质背景下找到标本，以记录它们的埋藏学。2)使用碳和氧的稳定同位素来发展该地区的化学地层学，并确定古气候随时间的变化趋势。3)利用稀土元素分析确定洞穴中化石埋藏的速度，并评估恐龙群落的营养结构。4)详细描述几个关键分类群的骨骼学，并对鹦鹉龙科、基底新角龙目和基底鸭嘴龙目的分类进行彻底的重新评估。（5）首次对鹦鹉龙科（Psittacosauridae）+基底新角龙属（Basal Neoceratopsia））和基底安息香龙科（Basal Styracosterna）+基底鸭嘴龙类（Basal Hadrosauria）进行了全面的种级系统发育分析。 拟议研究的结果将增加对恐龙新分类群的了解，以及在受控的埋藏学、生物地球化学和生物地层学框架内两个食草动物分支上升到优势地位的模式。

Early History of Horned and Duck-billed Dinosaurs: Discoveries inGansu, ChinaNSF EAR 1024671 PI Peter Dodson University of PennsylvaniaCo-PI You Hailu Chinese Academy of Geological Sciences, BeijingCo-PI Li Daqing, Fossil Research and Development Center, ThirdGeology and Mineral Resources Exploration Academy, Gansu Provincial Bureau of Geo-exploration and Mineral Development, LanzhouCo-PI Xu Xing, Institute of Vertebrate Paleontology and Paleoanthropology, BeijingAbstractTwo decades ago China was the third-ranked source of dinosaurs in the world, behind the United States and Mongolia. Since 1996 electrifying discoveries of avian and non-avian dinosaurs from Liaoning, Shandong, Henan, Inner Mongolia, Gansu and Xinjiang have vaulted China to the number one position in the world for dinosaur diversity. China has developed a new cohort of young researchers open to mutually enriching joint scholarship. Gansu Province in northwestern China has proven to be a rich source of abundant and exceptionally well-preserved dinosaur fossils during a critical interval of evolutionary time, the Early Cretaceous. High quality fossils have been described from Gansu only since 1997. In 2009 alone four new genera were described. We propose to sample fossil beds in Gansu that span a wide interval of the Early Cretaceous in order to document exhaustively the critical evolutionary transition from more basal herbivorous dinosaurs to more derived ones. The highly derived hadrosaurid-ceratopsid fauna that dominated Late Cretaceous faunas of the northern hemisphere had its origin during the critical interval of the Early Cretaceous when the archaic Mesozoic pteridosperm-cycadophyte-conifer-dominated flora began to change to the modern angiosperm-dominated flora. Sediments of the late Early Cretaceous Xinminpu Group of northwestern Gansu contain rich faunas of herbivorous dinosaurs. Both the ceratopsians and the ornithopods here are more derived than those of the mid Early Cretaceous Jehol Fauna of Liaoning. The proposed project includes five clear objectives: 1) to discover more horned and duck-billed dinosaurs and to locate specimens within their geological contexts to document their taphonomy. 2) To use stable isotopes of carbon and oxygen to develop a chemostratigraphy of the region and to determine trends in paleoclimate over time. 3) To use Rare Earth Element (REE) analysis to determine the rapidity of burial of fossils as in burrows and to assess trophic structure of the dinosaur communities. 4) To describe in detail the osteology of several key taxa, and to conduct a thorough re-evaluation of the taxonomy of Psittacosauridae, basal Neoceratopsia, and basal Hadrosauria. And 5) To perform the first comprehensive, species-level phylogenetic analyses for (Psittacosauridae + basal Neoceratopsia) and (basal Styracosterna + basal Hadrosauria), incorporating all newly described taxa. The result of the proposed research will be increased knowledge of both new taxa of dinosaurs and the pattern of ascent to dominance of two clades of herbivores within a controlled taphonomic, biogeochemical and biostratigraphic framework.