Late Cretaceous Amber Deposits from Saskatchewan, Canada

琥珀或树脂化石为古生物学家提供了古代陆地生态系统最详细的一瞥之一。在加拿大西部，在整个晚白垩世，琥珀矿藏与煤层、恐龙骨床和古代河流系统的遗迹有关。这种琥珀通常太小，太脆弱，不适合佩戴珠宝，但它捕捉到了昆虫和较大动物的小碎片(如羽毛)，以微观细节保存了这些包裹物及其软组织的3D图像。周围的琥珀还保留了一些原始的化学成分和稳定的同位素组成，使研究人员能够确定产生沉积物的树木群体，以及它们生活的条件。这项拟议研究的目标是对加拿大西部晚白垩世岩石中的琥珀进行密集采样，分析这种物质及其包裹体，并将它们置于古生态和昆虫进化的更大背景下。发现的昆虫包裹体将有助于填补存在于晚白垩世的昆虫化石记录中2000万年的空白，从而提高我们对白垩纪末灭绝事件前后昆虫多样性和灭绝的理解。琥珀还将提供有关当时存在的古代森林和栖息地条件的数据。总而言之，这些方面的研究将提高我们对晚白垩世陆地条件以及恐龙栖息地的理解。这项工作的结果将引起包括古生物学家、进化生物学家和地质学家在内的广泛科学家的兴趣，但也将对研究现代昆虫的研究人员产生影响。现代昆虫区系由四个高度多样化的昆虫目主导，这些昆虫目在白垩纪随着开花植物的崛起而多样性增长。这些昆虫群(甲虫、苍蝇、真虫，加上蚂蚁、黄蜂和蜜蜂)是陆地生态系统的主要贡献者，具有重要的生态和经济意义，但我们对它们的进化关系和对过去事件的反应的了解受到它们化石记录的限制。这项拟议的研究将阐明这些昆虫群体的关键时间间隔，并为灭绝事件后的化石记录提供一个比较点。

Amber or fossilized resin offers palaeontologists one of the most detailed glimpses of ancient terrestrial ecosystems. In western Canada, amber deposits are found associated with coal seams, in dinosaur bonebeds, and in the remains of ancient river systems throughout the Late Cretaceous. This amber is typically too small and fragile for jewelry, but it captures insects and small fragments of larger animals (such as feathers), preserving these inclusions and their soft tissues in 3D with microscopic detail. The surrounding amber also retains some of its original chemistry and stable isotopic composition, allowing researchers to identify the group of trees that produced the deposit, and the conditions that they were living under. The goal of the proposed research is to intensively sample the Late Cretaceous rocks of western Canada for amber, analyzing this material and its inclusions, and placing them in the larger context of palaeoecology and insect evolution. The insect inclusions that are found will help to fill in a 20-million-year gap in the fossil record of insects that exists in the Late Cretaceous, thus improving our understanding of insect diversification and extinction around the end-Cretaceous extinction event. The amber will also provide data about the ancient forests and habitat conditions that existed at the time. Together, these aspects of the research will improve our understanding of terrestrial conditions during the Late Cretaceous, and the habitats occupied by dinosaurs. The outcomes of this work will be of interest to a broad range of scientists, including palaeontologists, evolutionary biologists and geologists, but will also have implications for researchers working on modern insects. Modern insect faunas are dominated by four hyper-diverse insect orders that grew in diversity alongside the rise of flowering plants, in the Cretaceous. These insect groups (beetles, flies, true bugs, plus the order containing ants, wasps, and bees) are major contributors to terrestrial ecosystems, and have significant ecological and economic importance, yet our understanding of their evolutionary relationships and responses to past events is limited by their fossil record. The proposed research will shed light on a key time interval for these insect groups, and provide a comparison point for the fossil record after the extinction event.