Cretaceous angiosperm diversification

Crane P.R., Lidgard S. (1989) Angiosperm diversification and paleolatitudinal gradients in Cretaceous floristic diversity. 

Friis, E. M., Pedersen, K. R. and Crane, P. R. (1999) Early angiosperm diversification The diversity of pollen associated with angiosperm reproductive structures in Early Cretaceous floras from Portugal. Annals of the Missouri Botanical Garden, 86 259-296. 

Lupia, R., Crane, P. R. and Lidgard, S. (2000) Angiosperm diversification and Cretaceous environmental change. In Biotic Responses to Global Change The Last 145 Million Years (ed. S. J. Culver and P. F. Rawson). Cambridge University Press, Cambridge, pp. 207-222. 

Cretaceous 138 Ma Most continents widely separated continued radiation of dinosaurs angiosperms and mammals begin diversification mass extinction at end of period... 

The undoubted pleurocarps, however, are almost absent or at least extremely rare in earlier deposits. This fact, along with the other evidence, leads to the tentative conclusion (e.g.. Buck, 1991), that the evolution of pleurocarps followed the habitat diversification of the angiosperms, i.e., occurred in the Cretaceous. At the same time, an analysis of fossil data lead Krassilov and Schuster (1984) to the conclusion that the pleurocarpous mosses appeared no earlier than the Jurassic. 

The appearance of pleurocarpy was dated at 194-161 mya, significantly earlier than the radiation of the majority of pleurocarp lineages about 165-131 mya. This radiation coincides with the diversification of the angiosperms in the Early Cretaceous, but predates appearance of complex angiosperm forests in the early Cenozoic. The hypothesis that pleurocarpous mosses evolved to exploit the angiosperm forests is modified — pleurocarpous mosses diversified in the same time frame as the early angiosperms and the recovered pattern suggests a putative correlation of these diversification events. 

---