Data from: A complete fossil-calibrated phylogeny of seed plant families as a tool for comparative analyses: an example testing the â time for speciationâ hypothesis

Here, we generate a new time-calibrated phylogeny of seed plant families using Bayesian methods and 29 fossil calibrations. We present this phylogeny as a tool for comparative analyses. While there are various published phylogenetic hypotheses for plants which have a greater density of species sampling, we are still a long way from generating a complete phylogenetic tree for all ~300,000+ plants, and our study is useful because it samples all seed plant families. We provide one example of the utility of our phylogeny by investigating patterns of diversification across its branches. We calculated net diversification rate for each clade in the phylogeny and assessed the relationship between clade age and species richness. We then fit models of speciation and extinction to individual branches in the tree to identify major shifts in rates. Our data suggests that the majority of lineages are diversifying very slowly while a few lineages, distributed throughout the tree, are diversifying rapidly. Diversification is unrelated to clade age, no matter the age range of the clades being examined, contrary to both the assumption of an unbounded lineage increase through time, and the paradigm of fixed ecological limits. These findings are consistent with the idea that ecology plays a role in diversification, but rather than imposing a fixed limit, it may have variable effects on per lineage diversification rates through time.