Index Catalog // ScholarsArchive@OSU

Creator:: Rothwell, Gar W., Mapes, Gene, Stockey, Ruth A., and Hilton, Jason
Abstract:: Premise of the study: Pinaceae and nonpinoid species are sister groups within the conifer clade as inferred from molecular systematic comparisons of living species and therefore should have comparable geological ages. However, the fossil record for the nonpinoid lineage of extant conifer families is Triassic, nearly 100 million years older...
Resource Type:: Article

Creator:: Hillier, Kaitlin G. and Rothwell, Gar W.
Abstract:: Reexamination of fossilized plant material from the westernmost Pennsylvanian-age wetland flora in North America reveals that material of Pecopteris oregonensis Arnold represents a filicalean fern frond with annulate sporangia and anatomically preserved vascular tissues of the rachis. The frond, which is redescribed as Senftenbergia oregonensis (Arnold) Hillier et Rothwell comb....
Resource Type:: Article

Creator:: Dunn, Michael T. and Rothwell, Gar W.
Abstract:: Fifty-nine stems of Tetrastichia bupatides, numerous frond segments, and roots from Oxroad Bay, Scotland, have recently been analyzed. They reveal that many characters originally used to describe this species exhibit a wider range of variation than previously suspected. These data suggest that ribs of the protostele are most commonly four...
Resource Type:: Article

Creator:: Ryberg, Patricia E., Rothwell, Gar W., Stockey, Ruth A., Hilton, Jason, Mapes, Gene, and Riding, James B.
Abstract:: This study describes a specimen that extends the oldest fossil evidence of Pinus L. to the Early Cretaceous Wealden Formation of Yorkshire, UK (131-129 million years ago), and prompts a critical reevaluation of criteria that are employed to identify crown group genera of Pinaceae from anatomically preserved seed cones. The...
Resource Type:: Article

Creator:: Rothwell, Gar W. and Stockey, Ruth A.
Abstract:: A fossil seed cone with characters that have been hypothesized as transitional to the origin of crown group gnetophytes has been discovered in Lower Cretaceous deposits on Vancouver Island, British Columbia, Canada. This cone, described as Protoephedrites eamesii gen. et sp. nov., provides the first anatomically preserved fossil evidence for...
Resource Type:: Article

Creator:: Stockey, Ruth A. and Rothwell, Gar W.
Abstract:: A cylindrical permineralized conifer seed cone has been identified from the Officer Member of the Trowbridge Formation, near Izee, in east-central Oregon. The cone is preserved in a Middle Jurassic (Callovian) marine calcium carbonate concretion, associated with araucarian seed cones, conifer twigs and wood, cycad seeds, fern rachides, and lycopodialean...
Resource Type:: Article

Creator:: Rothwell, Gar W., Mapes, Gene, Stockey, Ruth A., and Hilton, Jason
Abstract:: Premise of research. A third genus of anatomically preserved conifer seed cones has been recognized from a Late Jurassic deposit in northeastern Scotland. This cone is described as Bancroftiastrobus digitata Rothwell, Mapes, Stockey et Hilton. Methodology. The cone was sectioned with the classic coal ball peel technique and studied and...
Resource Type:: Article

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