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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,ObirastrobusandEathiestrobus. A new pinaceous cone from the Early Cretaceous of California is described asPityostrobus pluriresinosasp. nov., adding to the diversity of known Cretaceous pinaceous cones. Phylogenetic analysis places the new fossil cone in the pinoid clade along withPinus,Eathiestrobusand numerous species ofPityostrobus. Combined with a non-metric multidimensional scaling ordination, the data reinforce that whilePityostrobusdoes not represent a natural genus, it likely reflects the rapid evolution of Pinaceae by showing that ovulate cone morphospace was widely occupied byPityostrobusthat 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. [ABSTRACT FROM AUTHOR]

Studies a species of the osmundaceous fern Millerocaulis from the Early Cretaceous, Upper Chickaballu Member of the Budden Canyon Formation in California. Comparison to living and fossil ferns in the family Osmundaceae; Stem characteristics; Root traces; Genera with the closest similarity to the specimen.