Fig. 1.

An overview of hypothetical determinants of conifer diversification over time. Conifer evolution was punctuated by (A) four known mass extinction events (red arrows). Biotic events (B), such as the evolution of leaf shape and the appearance of competitor clades (e.g., angiosperms), are likely to be important drivers of diversification. Environmental (abiotic) changes may also impact diversity dynamics, including the paleoclimate (C), with global temperature (red curve highlighting the cooling and warming events), atmospheric carbon (black curve), or sea-level fluctuations (blue curve), as well as the paleogeology (D), such as plate tectonic movements (global paleogeographic changes) or volcanism. CAMP, Central Atlantic magmatic province. C, Carboniferous; D, Devonian; J, Jurassic; K, Cretaceous; Ng, Neogene; P, Permian; Pg, Paleogene; Tr, Triassic.