Klymiuk, Ashley A. , Stockey, Ruth A. , Rothwell, Gar W. .
Evidence for phylogenetic relationships among conifers: the first organismal concept for an extinct species of Pinus.
The Eocene Princeton chert of southern British Columbia, Canada, represents a peat-forming mire with autochthonous preservation including aquatic plants, the components of which are frequently in situ with respect to life habit. This preservation provides the opportunity to develop organismal concepts for a number of extinct species, including two ferns, two eudicots, and the taxodiaceous conifer, Metasequoia milleri. In this study, the concept of Pinus arnoldii Miller is expanded to encompass the structure, growth, development, and reproductive biology of an additional species of extinct plants. We utilized a combination of interconnected organs, histologically diagnostic features, and statistically significant patterns of association to develop a species concept. In addition to the P. arnoldii ovulate cones, this species concept includes woody stems with attached five-needled fascicles previously described as P. similkameenensis Miller, pollen cones with bisaccate grains, and roots with attached coralloid systems containing ectomycorrhizae. Organs in various developmental stages provide evidence for numerous aspects of growth and reproductive biology, including pollination biology and seed cone development. The various organs have a combination of features that are, in extant species, found in different subgenera (Sylvestres, Quinquefolia, and Parrya) of Pinus. The P. arnoldii plant appears to have grown adjacent to the depositional basin represented by the Princeton chert. This is the first organismal concept to be developed for an extinct species of Pinaceae, providing a novel combination of characters for resolving relationships among the subgenera of living Pinus species.
Log in to add this item to your schedule
1 - University of Alberta, Department of Biological Sciences, Biological Sciences Centre, Cw 405, Edmonton, Alberta, T6G 2E9, Canada
2 - Ohio University, Department of Environmental & Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Superior A/Cliff Lodge - Level C
Date: Monday, July 27th, 2009
Time: 10:45 AM