Vavrek, Matthew J. , Stockey, Ruth A. , Rothwell, Gar W. .
Permineralized Osmunda pinnae with attached sporangia containing spores from the Lower Cretaceous of British Columbia, Canada.
Seven anatomically preserved fertile osmundaceous pinna fragments have been identified from calcareous marine nodules from the Apple Bay locality on Vancouver Island, British Columbia. Palynological studies indicate that the site is early Cretaceous (Hauterivian - Barremian) in age. Specimens were studied using the cellulose acetate peel technique and scanning electron microscopy. A reconstruction of sporangial attachment and structure was done using AMIRA 3.1 three dimensional visualization software. The largest specimen has nine sporangia attached to a non-laminate system in a loose cluster. Sporangia, 550-650 Ám in diameter, have a lateral annulus that is two to three cells tall and nine to twelve cells wide. Spheroidal, trilete spores, 40-52 Ám in diameter, have coarsely tuberculate exospore with some fused tubercles, and echinate perispore on the tips of the tubercles. Sporangial structure and spores most closely resemble those of Osmunda, Subgenus Osmunda, and are similar to O. regalis L. Despite the excellent fossil record of permineralized stems of Osmundaceae, anatomically preserved sporangia with spores are rare. These mesofossils add to our growing appreciation for the antiquity of modern taxa of the Osmundaceae. They also emphasize the excellent preservation of plant material at Apple Bay, and underscore the unique potential for such specimens to enhance our understanding of the pattern of phylogeny among modern Filicales.
1 - Ohio University, Department of Environmental and Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
2 - University of Alberta, Department of Biological Sciences, CW 405 Biological Sciences Building, Edmonton, Alberta, T6G 2E9, Canada
Presentation Type: Paper
Location: Maybird (Cliff Lodge)
Date: Wednesday, August 4th, 2004
Time: 3:15 PM