Vertebrate paleontology of terrestrial and marine squamates: testing the relationships of lepidosauria within sauropsida

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My proposed research is focused on understanding the origin, evolution, and phylogeny of fossil and living snakes and lizards. Our current understanding of their evolution is based on information obtained from living species, largely ignoring the fossil record (250mya-Present). The importance of the fossil record as a source of data on anatomical novelty cannot be overstated. My research approach is to use all available evidence from fossils, i.e., the anatomy, biostratigraphy and palaeobiogeography in the construction of hypotheses, along with all available data from living snakes and lizards (anatomy through to molecules). To connect this proposed research cycle to past and future cycles, I have identified two principle "Research Goals": 1) Increase the taxonomic breadth of my studies of terrestrial and marine, fossil and modern snakes and lizards; 2) Initiate a detailed assessment of the morphological evolution of snakes and lizards by studying the anatomy of successively older groups of more primitive reptiles. Collaborations and student/PDF training are essential to each project outlined here. Research Goal #1 will be achieved by acquiring new data on on the oldest known terrestrial lizards (Upper Triassic, India), on Jurassic, Cretaceous and Eocene-aged lizards from North America and Europe (in some cases considered closely related to monitor lizards, gekkos, skinks, and in others, very distantly related). I will continue my study of Cretaceous-aged mosasaur fossils from Morocco and Alberta and will revise a number of currently recognized groups such as the genera Mosasaurus and Prognathodon. For snakes, I will collect new hard and soft anatomical data on blind burrowing snakes, newly described fossil snakes, and Oligocene-aged boiid snakes from North America, as well as examining the evolution of teeth in snakes. Research Goal #2 will be addressed by conducting fieldwork in the Chinle Formation (North American Triassic) prospecting for Upper Triassic snakes/lizards/sphenodontians, by identifying the evolutionary morphology of snake and lizard features in their most ancient relatives (Triassic to Jurassic), and by conducting high level phylogenetic studies of relationships.