A new species of Pityostrobus (Pinaceae) from the Cretaceous of California: moving towards understanding the Cretaceous radiation of Pinaceae

作者：Smith Selena Y^*; Stockey Ruth A; Rothwell Gar W; Little Stefan A

来源：Journal of Systematic Palaeontology, 2017, 15(1): 69-81.

DOI：10.1080/14772019.2016.1143885

• Eathiestrobus
• Obirastrobus
• ovulate cone
• Pinaceae
• Pityostrobus
• Pseudoaraucaria

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 numerous species of Pityostrobus. 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 that 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 morphologies typical of the pinoid clade 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 early diversification for Pinaceae.

• 出版日期2017