Palaeobiology of Canadian Cretaceous amber: An exceptional record of Late Cretaceous Hymenoptera, with contributions to additional taxa and the study of amber.

摘要

Canadian amber provides a glimpse of a Late Cretaceous (Campanian) ecosystem preserved in exquisite detail. Here we document one of the best-preserved assemblages of Hymenoptera (ants, bees, and wasps) in the Mesozoic. Contributions are also made to the study of a broader range of taxa and the development of amber research.;Amber offers the best fossil record for diminutive terrestrial organisms with a low preservation potential, such as micro-hymenopterans. Canadian amber preserves a broad range of hymenopteran taxa, but is strongly biased towards smaller taxa, so members of 'Parasitica' (a grade of parasitoid hymenopterans) are most thoroughly represented. To date, 30 families, 38 genera and 70 species of Hymenoptera have been identified in the assemblage: 36 of these species, six of the genera, and two of the families stem from the body of work summarized in this dissertation. Herein, Canadian amber specimens are contrasted against those recovered from other Cretaceous amber deposits, and large-scale palaeobiogeographic and stratigraphic range patterns are discussed.;New taxa are documented within Neuroptera (lacewings) and Hemiptera (true bugs), as these specimens constitute important records for their respective families (Rhachiberothidae and Microphysidae). The most abundant and diverse assemblage of feathers and putative protofeathers yet to be recovered from Mesozoic amber is also described. Careful screening of Canadian amber collections for inclusions as small as micro-hymenopterans has yielded a wide range of inclusions of high scientific value. Contributions to the study of these specimens will promote additional research into a somewhat overlooked palaeontological resource.;Finally, the versatility of stable isotope analyses in the study of amber is demonstrated. This technique is used to explore the source of Canadian amber, and the role of insect attacks in the formation of amber deposits. This new approach to the study of amber provides a more comprehensive account of conditions in the amber-producing forest, and allows palaeoecological hypotheses to be tested through modern analogues.