Tracking ecology over geological time: evolution within guilds of vertebrates.

Community structure, stability and change can be observed in the fossil record over timescales that far exceed what is possible in the present. Recent quantitative studies on ecological structure withion ancient guilds of various vertebrate predators, inlcuding birds, mammals and reptiles, have revealed a common pattern of iterative replacement of feeding ecomorphs over time, despite large differences in phylogenetic composition. As a result, patterns of resource division among sympatric carnivores remain stable over many millions of years and probably reflect interspecific competition and aspects of the food resource.