Abstract

The evolutionary history of Pinaceae is documented by numerous fossils, which include a number of anatomically preserved ovulate cones with many systematically informative characters. To date, four extinct genera have been recognized: Pseudoaraucaria, Pityostrobus, Obirastrobus, and Eathiestrobus. A new pinaceous cone from the Early Cretaceous of California is described as Pityostrobus pluriresinosa sp. nov. adding to the diversity of known Cretaceous pinaceous cones. Phylogenetic analysis places the new fossil cone in the pinoid clade along with Pinus, Eathiestrobus, and most of the other species of Pitystrobus. Combined with a non-metric multidimensional scaling ordination, the data reinforce that while Pityostrobus does not represent a natural genus, it likely reflects the rapid evolution of Pinaceae by showing that ovulate cone morphospace was widely occupied by Pityostrobus and has become more restricted in extant genera. Early Cretaceous taxa from Europe and eastern North America show the broadest occupation of morphospace, which then became more restricted to pinoid morphologies in the Late Cretaceous. Taxa from western North America and Asia are more similar to extant genera and occupy a smaller part of the morphospace, highlighting that eastern North America-Europe probably represents an original centre of diversification for Pinaceae.