Deconstructing Biases in the Fossil Record of the Oldest Animals: Experimental and Geochemical Studies in Soft-Tissue Preservation

解构最古老动物化石记录中的偏差：软组织保存的实验和地球化学研究

• 批准号: 435402-2013
• 负责人: Laflamme, Marc
• 金额: $ 2.33万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=656330
• 关键词: Deconstructing; Biases; Fossil; Record; Oldest

The fossil record is fickle and biased. Sites that preserve soft-bodied organisms, as opposed to typical fossil assemblages of bones, teeth, and shells, are exceedingly rare and truly exceptional (Konservat-Lagerstätten of Seilacher, 1970). Lagerstätten represent the richest source of anatomical information for extinct species, offer more complete views of diversity patterns in deep time, and ultimately open a window into the workings of ancient ecosystems typically afforded only to biologists studying modern systems. However, there is a growing recognition that Lagerstätten are fraught with preservational biases, which are in urgent need of systematic characterization. For instance, Lagerstätten are unevenly distributed through geological time, are typically restricted to specific environmental settings, and preferentially preserve certain tissue types over others (Allison and Briggs, 1993; Schiffbauer and Laflamme, 2012). Interdisciplinary studies that examine the physical, chemical, and biological factors controlling the tempos and modes of fossil preservation (taphonomy) are offering critical new perspectives on the content and accuracy of the fossil record, and are a necessary first step in correctly identifying trends in the evolution of life. My long-term research objective is to elucidate the taphonomic pathways responsible for fossilization, and to identify physical, chemical, and biological controls biasing the fossil record.****The proposed experimental and taphonomic studies of soft-tissue preservation have profound implications on evaluating the fidelity of the fossil record, specifically at the dawn of animal life. My work proposes to undertake the first comprehensive investigation of Ediacaran taphonomic scenarios, combining experimental taphonomy, and geochemical analyses in order to finally understand their distribution in time and space. Ultimately, taphonomic ground-truthing is necessary to validate all paleontological trends at any scale extrapolated from the fossil record.

化石记录是反复无常和有偏见的。保存软体生物的地点，与典型的骨骼、牙齿和贝壳化石组合相反，是极其罕见的，而且是真正的例外（Konservat-Lagerstätten of Seilacher, 1970）。Lagerstätten代表了灭绝物种最丰富的解剖学信息来源，提供了更完整的关于深时间多样性模式的观点，并最终打开了一扇窗户，进入古代生态系统的运作，通常只有生物学家才能研究现代系统。然而，越来越多的人认识到Lagerstätten充满了保存偏见，迫切需要系统的表征。例如，Lagerstätten在地质年代中分布不均匀，通常局限于特定的环境设置，并且优先保存某些组织类型（Allison和Briggs, 1993； Schiffbauer和Laflamme， 2012）。研究控制化石保存（埋藏学）速度和模式的物理、化学和生物因素的跨学科研究，为化石记录的内容和准确性提供了重要的新视角，是正确识别生命进化趋势的必要的第一步。我的长期研究目标是阐明导致石化的埋藏学途径，并确定使化石记录偏斜的物理、化学和生物控制。****提出的软组织保存的实验和地形学研究对评估化石记录的保真度具有深远的意义，特别是在动物生命的开端。我的工作计划是对埃迪卡拉纪的埋藏情景进行首次综合调查，将实验埋藏学与地球化学分析相结合，最终了解它们在时间和空间上的分布。最终，为了验证从化石记录推断出的任何尺度的古生物学趋势，地面学的地面真相是必要的。