EAR-PF: A multidisciplinary investigation of biotic and environmental change within the Triassic-Jurassic strata of southwestern Honshu, Japan

本杰明·T. Breeden III获得了NSF地球科学博士后奖学金，在日本国立自然科学博物馆的Makoto Manabe博士的指导下，对日本爬行动物时代的开始进行研究。“爬行动物时代”或中生代是跨越三叠纪、侏罗纪和白垩纪（约2.52 - 6600万年前）的地质时间间隔，在此期间，爬行动物如非鸟类恐龙（即，恐龙（鸟类除外）统治着陆地生态系统。在整个中生代早期，地球上的生命经历了与全球环境变化有关的两次大规模灭绝，并从中恢复过来，导致许多脊椎动物群体的进化和多样化，这些动物仍然是现代生态系统的重要组成部分。近几十年来，中生代早期脊椎动物化石记录受到了严格的科学审查;然而，尽管日本研究人员进行了世纪的研究，但日本晚三叠世和早侏罗纪时代的脊椎动物化石地层仍然被日本以外的研究人员广泛忽视。本项目将重点研究本州西南部的三叠纪-侏罗纪地层（日本最大的岛屿），并结合日本博物馆收藏的脊椎动物化石，野外地质和古生物学观察，实验室地球化学分析，以及将日本科学文献翻译成英文，以阐明超大陆东北缘沿着脊椎动物进化与环境变化之间的关系泛大陆，日本的这一地区在整个中生代早期都处于这个位置。该项目将通过公开讲座、本科生辅导和博物馆展览设计促进外联和教育;它将通过面向科学和普通读者的出版物，使日本中生代早期地质学和古生物学的某些研究首次向更广泛的英语读者开放。日本已建立的中生代早期脊椎动物化石记录稀少但多样，日本许多含脊椎动物化石的早中生代地层缺乏精确和准确的多指标数据集来评估有关古生物地理学和环境驱动的生物变化的假设。因此，这些地层是研究这些变化的相对未开发的潜在资源。在日本最多产的含脊椎动物化石的早中生代地层中，有上三叠世矿群、下-中侏罗世丰良群和黑沼群，它们都出现在本州西南部的各个地区。该项目将通过对这些地层进行古生物学和地质勘察，并对日本各地博物馆收藏的这些地层和其他三叠纪和侏罗纪地层中现有的中生代早期脊椎动物化石记录进行修订，建立整个中生代早期盘古大陆东北部环境变化和脊椎动物进化的综合记录。将利用系统发育和地理学方法对这些地层中脊椎动物化石的解剖和演化历史进行评价，并建立这些地层的碳同位素化学地层学，以对比与相关环境危机（例如，Carnian Pluvial Event; Toarcian Ocean Anovalent Event）。这项工作将有助于在区域和全球范围内对整个中生代早期的环境和生物变化进行更广泛的了解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Benjamin T. Breeden III has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out research on the beginning of the Age of Reptiles in Japan under the mentorship of Dr. Makoto Manabe at the National Museum of Nature and Science. The “Age of Reptiles,” or Mesozoic Era, is the interval of geologic time spanning the Triassic, Jurassic, and Cretaceous periods (~252–66 million years ago) during which reptiles such as non-avian dinosaurs (i.e., dinosaurs other than birds) dominated terrestrial ecosystems. Throughout the early Mesozoic, life on Earth endured and recovered from two mass extinctions tied to global environmental change, resulting in the evolution and diversification of many groups of vertebrate animals that remain important components of modern ecosystems. The early Mesozoic vertebrate fossil record has received heavy scientific scrutiny in recent decades; however, vertebrate fossil-bearing strata from the Late Triassic and Early Jurassic epochs in Japan have remained widely overlooked by researchers outside of Japan despite over a century of research by Japanese researchers. This project will focus on Triassic-Jurassic strata in southwestern Honshu (the largest of the main Japanese islands) and integrate observations of vertebrate fossils from Japanese museum collections, field geological and paleontological observations, laboratory geochemical analyses, and the translation of Japanese scientific literature into English to elucidate the relationship between vertebrate evolution and environmental change along the northeastern margin of the supercontinent Pangea, where this region of Japan was positioned throughout the early Mesozoic. This project will facilitate outreach and education via public lectures, undergraduate mentoring, and museum exhibit design; and it will make certain research on early Mesozoic geology and paleontology in Japan accessible to a broader English-speaking audience for the first time via publications for both scientific and general readers.The established early Mesozoic vertebrate fossil record of Japan is sparse but diverse, and many vertebrate fossil-bearing early Mesozoic strata in Japan lack precise and accurate multiproxy datasets with which to evaluate hypotheses regarding paleobiogeography and environmentally driven biotic change. These strata are therefore relatively untapped potential resources for studying these changes. Among the most productive vertebrate fossil-bearing early Mesozoic strata in Japan are the Upper Triassic Mine Group, and the Lower-Middle Jurassic Toyora and Kuruma groups, all of which crop out across regions in southwestern Honshu. This project will establish an integrated record of environmental change and vertebrate evolution in northeastern Pangea throughout the early Mesozoic via paleontological and geological reconnaissance of these strata and a revision of the existing early Mesozoic vertebrate fossil records from these and other Triassic and Jurassic strata in museum collections across Japan. Phylogenetic and biogeographic methods will be used to evaluate the anatomy and evolutionary history of the vertebrate fossils from these strata, and the carbon isotope chemostratigraphy of these strata will be established for correlation of major carbon isotope perturbations associated with relevant environmental crises (e.g., Carnian Pluvial Event; Toarcian Ocean Anoxic Event). This work will contribute to the broader knowledge of environmental and biotic change throughout the early Mesozoic at regional and global scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.