Revolutions In Mesozoic Ecosystems
Welcome to RIME
Changes in Mesozoic ecosystems, such as increasing predation intensity, ecospace utilization, and disturbance are thought to have led to the diversification and evolution of species. But how have changes in richness and ecospace utilization altered community structure and functioning? RIME aims to examining how such changes may have altered ecosystem structure and functioning, by reconstructing food webs.
Increasing ecospace utilization, predation intensity, motility, infaunality, and disturbance suggest that the ecological complexity of benthic marine environments has increased through geologic time as specialized morphologies and functions have evolved. In addition, several fundamental changes in trophic structure are thought to have occurred through the Phanerozoic as a result of shifts in faunal dominance in benthic marine communities. Food web models based on these evolutionary faunas suggest that increasing Phanerozoic taxonomic diversity and ecological complexity, coupled with increasing intensity of biotic interactions, would have resulted in more complex food webs. The examination of ancient food webs therefore presents an opportunity to determine whether trophic organization has changed, and to understand the evolutionary mechanisms that have contributed to historical patterns of community structure.
Periods of taxonomic and ecological diversification are candidates for changes in ecosystem structure and function, if indeed they have occurred. The Mesozoic is such a time, as abrupt biotic reorganization occurred during and after the Late Permian and Late Triassic mass extinctions. The end Permian extinction resulted in Early Triassic ecosystems with reduced taxonomic and ecological diversities, and communities following this extinction underwent significant changes in the relative abundance and composition of organisms within various trophic levels and modes of life. During the Mesozoic, several important groups of predators radiated in conjunction with an increase in anti-predatory prey adaptations and a decrease in the relative abundance of sessile, suspension feeding organisms, suggesting that organisms evolved in response to predators and increased predation intensity (the Mesozoic Marine Revolution, MMR).
This project aims to test whether observed escalatory trends in increasing predation intensity and changes in biodiversity correspond with changes in community structure, trophic organization, and stability, by examining the relationship between trophic structure and community dynamics in Mesozoic marine communities from the Tethys Sea.