Klymiuk, Ashley A. , Stockey, Ruth A. .
Evolution of Pinaceae: a new seed cone from the Cretaceous of British Columbia.
An immature, isolated seed cone, permineralized in a carbonate concretion from the Apple Bay locality of Vancouver Island, British Columbia (Lower Cretaceous, Valanginian-Hauterivian) is described using cellulose acetate peels. The cone is at least 3.2 cm long and 0.5 cm wide. It was deposited at the pollination stage, and bisaccate pollen is found within the micropyles of several immature ovules, providing insight into pollination biology. The cone axis has a sclerenchymatous pith, surrounded by a ring of secondary xylem composed entirely of tracheids with helical and scalariform thickenings. All cortex is sclerotic with several resin canals of uniform diameter. Vascular traces to the bract and scale have separate origins and the scale trace is abaxially concave. The bract separates from the scale laterally, has an abaxial lobe, and two resin canals accompany a terete vascular trace. The ovuliferous scale is sclerotic, with resin canals adaxial and abaxial to the vascular trace throughout its extent. The ovuliferous scale bears two seeds which have wings derived from the scale tissue. The seeds are separated by a small interseminal ridge. Morphological cladistic analyses of cone characters from extant and fossil members of Pinaceae clarified several other relationships within the family, and strengthened support for known monophyletic groups. The phylogenetic position of this new cone was unresolved, but it does have many characters in common with extant Picea. A Picea-like leaf, Midoriphyllum piceoides Stockey et Wiebe, ubiquitous at Apple Bay, may represent the leaf of this plant. This cone provides further evidence for the great diversity and rapid evolution of the Pinaceae during the Cretaceous.
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1 - University of Alberta, Department of Biological Sciences, Biological Sciences Centre, CW, 405, Edmonton, AB, T6G 2E9, Canada
2 - University of Alberta, Department of Biological Sciences, Biological Sciences Centre, Cw 405, Edmonton, Alberta, T6G 2E9, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: 555B/Convention Center
Date: Monday, August 2nd, 2010
Time: 9:30 AM