Description
The Early Palaeozoic diversification in the marine realm comprises twomain events, the Cambrian Explosion” (CE) and the Great Ordovician Biodiversification Event” (GOBE). Traditionallythe two events are seen as either one coherent process within a unifying macroevolutionary dynamics or as the composite result of processes at multilevel spatial and temporal scales. The diversification can also be conceptualised as a pattern emergent from lower taxonomic levels and lower spatial scale. In this perspective the global
marine diversity trend would represent more than a trivialaddition of more and more taxa, but the appearance of new structural phenomena that in itself led to ever increasing numbers of coexisting taxa. We estimated diversity trends and evolutionary rates for the Cambrian–Silurian interval in unprecedented time resolution, applying capture-recapture modelling methods.
As a result we identified two main Early Palaeozoic diversity shifts reflectingthe CE and GOBE peaks, respectively.Here we provide additional statistical evidence for the significance of these events and present the results of several tests for detecting significant diversity change-points.Our estimated evolutionary rates are diversity independent and hence, diversity and turnover can be interpreted as variables describing the state of the Early Palaeozoic marine ecosystem independently from each other. This is most evident in a major temporal discrepancy between change-points of diversity and diversification rates and change-points of per-capita rates of extinction and origination.The global per capita turnover rates dropped drastically during the earliest Ordovician and atthe same time the average genus longevity increased. This Early Ordovician drop in turnover rates and the simultaneous rise in genus longevity can be interpreted as a condition, setting the stage for the GOBE.
| Period | 12 Jul 2018 |
|---|---|
| Event title | 5th International Palaeontological Congress |
| Event type | Conference |
| Location | Paris, FranceShow on map |
| Degree of Recognition | International |