"Morphology, Homology, Phylogeny, and Biogeography of Early Vertebrates and Fossil Fishes"

在特殊的化石沉积物中发现的完整的鱼化石骨骼提供了丰富的信息。在我的实验室里，我们把重点放在这些沉积物上，以了解生活在志留纪和早期泥盆纪（4亿到4.3亿年前）的物种的起源、关系、生活方式和解剖学特征，当时早期有颌和无颌的脊椎动物数量众多，种类繁多。这些特殊的化石矿床位于西北地区的麦肯齐山脉和加拿大北部的其他地方。

Complete skeletons of fossil fishes found in exceptional fossil deposits yield a wealth of information. In my lab we focus on these deposits to learn about the origins, relationships, mode of life, and anatomical features of species that lived during Silurian and Early Devonian time (400 to 430 million years ago), when early vertebrates with jaws and their jawless relatives were abundant and diverse. These exceptional fossil deposits are in the Mackenzie Mountains, NWT and elswhere in northern Canada. One locality contains at least 73 species of early vertebrates, including jawless forms and early jawed vertebrates related to sharks and bony fishes. Most are complete skeletons. Some of them allow us to examine growth of the skeleton. Others tell us about the evolution of body features such as paired fins, teeth, ears, and guts. These studies involve careful comparisons with fossils found elsewhere in the world and use modern computerized methods of reconstructing the tree of life. In the Cretaceous of Morocco we are studying marine fishes from another extraordinary fossil site. Many species of fishes have been recovered and are under study, with emphasis on their evolutionary relationships and their geographic histories. We also study growth rates of fossil fishes calculated from fossil scales and vertebrae, to see how their growth rates responded to ancient climate change. The relationships of living fishes are being clarified by modern studies of their anatomy and their DNA. The new ideas of relationships lead us to re-examine fossils of the same groups, to see whether they have been interpreted correctly in the past. This type of study will be carried out with colleagues in the USA and will focus on the freshwater fishes in the cod, dory, beardfish, troutperch, pirateperch, pike, and mudminnow families.