Professor Susan E. Evans
The group has a primary research interest in
herpetology, with the major focus on the evolution, systematics and
palaeobiogeography of small reptiles and amphibians. Our work incorporates both
fossil and living genera.
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Herpetology is the study of reptiles and amphibians, living and extinct. Our group has particular interests in the evolution, diversification, functional morphology and relationships of lizards and their relatives; in the early evolution of living amphibian groups; and in a small range of exclusively fossil clades. Although our principal focus is palaeontological, building hypotheses on the basis of fossil material requires an understanding of modern musculoskeletal structure, function and ontogeny, as well as phylogenetic relationships. We use a mixture of techniques including cladistics, morphometrics, scanning electron microscopy, and anything else that sheds light on the major questions at hand – namely when, where and how these groups diversified, how modern characteristics evolved and in what order, how the groups diversified through changing continental configurations, and why some groups became extinct while others survived and flourished. The canvas on which we work is necessarily a broad one, but each individual project aims to fill in one further piece of the fine detail. Lizards and lissamphibians generally have small, delicately built skeletons and are not ideal candidates for fossilisation. Consequently, their fossil remains are rare, and localities with suitable preservational conditions are scattered around the world. In addition to several UK based projects, we are currently collaborating with colleagues in Continental Europe (Spain, France, Poland), Japan, India, Australia and North America, involving fossil deposits ranging in age from Early Triassic (circa 240 Myrs BP) to Recent (subfossil). However, fossils cannot be studied in isolation, particularly if they have close living relatives. Their incorporation into phylogenetic trees based on modern taxa is important in the testing of the phylogenetic hypotheses represented by those trees. Moreover, many fossil taxa are represented by single specimens, frequently incomplete, and it is important to know how representative such specimens are of the taxon as a whole, i.e. how much skeletal variation (ontogenetic, sexual, regional) occurs within modern species and how do we distinguish such intraspecific variation from phylogenetically significant variation characterising discrete taxa. Such studies have been made for a few vertebrate groups (e.g. primates), but very little has been done on reptiles and amphibians. There are also many questions relating to the individual characters used in phylogenetic analysis, particularly with respect to the influence of function and development on skeletal features, and also the independence or interdependence of apparently discrete features. |
Albanerpetontid amphibian,
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Field crew at Shokawa site, Gifu Prefecture, Japan. Sample publications: |
