Burgess Shale fossils from Marble Canyon (Canadian Rockies) and the early diversification of animals

发现于1909年的不列颠哥伦比亚省的伯吉斯页岩对我们了解大约5亿年前发生的著名的“寒武纪大爆发”期间早期动物的多样化至关重要。2012年，由皇家安大略博物馆领导的探险队在库特奈国家公园的大理石峡谷附近发现了一个新的伯吉斯页岩地点，位于原址东南40公里处，为我们对地球历史上这一关键事件的理解增添了戏剧性的新篇章。大理石峡谷的宝藏之一是Metaspriggina，世界上最完整的原始化石鱼（Conway Morris & Caron，Nature，2014）。这项研究计划的主要目标集中在伯吉斯页岩和大理石峡谷的化石上，目的是确定不同物种与化石和现存动物群体的关系，它们在环境中如何相互作用，记录这些古老群落在空间和时间上的变化，并描述化石沉积物的地质背景。为了实现我们的第一个目标，我们将研究新收集到的化石环节动物蠕虫和节肢动物。这些保存完好的化石将为这些生物群体的早期进化、多样性和各种体型提供重要的见解。我们将开发新的工具来超越化石标本的表面，包括使用回旋加速器技术来检测仍然嵌入岩石中的结构，这些结构太薄或太脆弱，无法用机械工具暴露。 * 第二个目标是通过在加拿大落基山脉公园的不同地点进行有针对性的实地考察，发掘新的化石，以确定斯蒂芬页岩组（产生伯吉斯页岩化石的地质单位）内化石沉积的范围-它们是如何分布的，以及该地层内不同化石组合的地层关系。我们将研究这些化石动物是如何相互关联的，以及组成这些古老群落的生物体的变化和它们所处环境的变化。

Discovered in 1909, the Burgess Shale of British Columbia is critical to our understanding of the early diversification of animals during the famous “Cambrian Explosion” that occurred about half a billion years ago. The 2012 discovery by a Royal Ontario Museum-led expedition of a new Burgess Shale locality near Marble Canyon in Kootenay National Park, 40 km southeast of the original site, adds a dramatic new chapter to our understanding of this key episode in Earth's history. Among the treasures from Marble Canyon is Metaspriggina, the most complete primitive fossil fish in the world (Conway Morris & Caron, Nature, 2014).*** The main goals of this research program focused on fossils from the Burgess Shale and Marble Canyon are to determine how the different species are related to fossil and extant groups of animals, how they interacted in their environments, to document changes in these ancient communities over space and time, and to characterize the geological context of the fossil deposits.*** To meet our first objective, we will study new collections of fossilized annelid worms and arthropods. These exceptionally preserved fossils will offer critical insights into the early evolution, diversity and variety of body shapes of these groups of organisms. We will develop new tools to look beyond the surface of fossil specimens, including the use of cyclotron technology to detect structures still embedded in rocks and which are too thin or fragile to be exposed with mechanical tools. *** The second objective involves unearthing new fossils through targeted fieldwork at various locations in the Canadian Rockies Mountain Parks, to determine the extent of the fossil deposits within the Stephen Shale Formation (the geological unit yielding Burgess Shale fossils) — how spread out they are and the stratigraphic relationships of the different fossil assemblages within that formation. We will study how these fossil animals were related to each other, as well as variations in the organisms making up these ancient communities and variations in their environments.