Biodiversity tracks temperature over time.

The geographic distribution of life on Earth supports a general pattern of increase in biodiversity with increasing temperature. However, some previous analyses of the 540-million-year Phanerozoic fossil record found a contrary relationship, with paleodiversity declining when the planet warms. These contradictory findings are hard to reconcile theoretically.

Avian wing proportions and flight styles: first step towards predicting the flight modes of mesozoic birds.

We investigated the relationship between wing element proportions and flight mode in a dataset of living avian species to provide a framework for making basic estimates of the range of flight styles evolved by Mesozoic birds. Our results show that feather length (f(prim)) and total arm length (ta) (sum of the humerus, ulna and manus length) ratios differ significantly between four flight style groups defined and widely used for living birds and as a result are predictive for fossils. This was confirmed using multivariate ordination analyses, with four wing elements (humerus, ulna/radius, manus, primary feathers), that discriminate the four broad flight styles within living birds.

Dinosaur diversity and the rock record.

Palaeobiodiversity analysis underpins macroevolutionary investigations, allowing identification of mass extinctions and adaptive radiations. However, recent large-scale studies on marine invertebrates indicate that geological factors play a central role in moulding the shape of diversity curves and imply that many features of such curves represent sampling artefacts, rather than genuine evolutionary events. In order to test whether similar biases affect diversity estimates for terrestrial taxa, we compiled genus-richness estimates for three Mesozoic dinosaur clades (Ornithischia, Sauropodomorpha and Theropoda).

Phanerozoic trends in the global diversity of marine invertebrates.

It has previously been thought that there was a steep Cretaceous and Cenozoic radiation of marine invertebrates. This pattern can be replicated with a new data set of fossil occurrences representing 3.5 million specimens, but only when older analytical protocols are used.

Cyclicity in the fossil record mirrors rock outcrop area.

In a recent article, Rohde & Muller (Rohde & Muller 2005 Nature 434, 208-210) identified a strong 62 Myr cyclicity in the history of marine diversity through the Phanerozoic. The data they presented were highly convincing, yet they were unable to explain what process might have generated this pattern. A significant correlation between observed genus-level diversity (after removal of long-term trends) and the amount of marine sedimentary rock measured at a surface outcrop in Western Europe is demonstrated.