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...
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Premise of study: Sequence analyses for Pinaceae have suggested that extant genera diverged in the late Mesozoic. While the fossil record indicates that Pinaceae was highly diverse during the Cretaceous, there are few records of living genera. This description of an anatomically preserved seed cone extends the fossil record for...
Forest-fire policy of U.S. federal agencies has evolved from the use of small
patrols in newly created National Parks to diverse policy initiatives and institutional arrangements
that affect millions of hectares of forests. Even with large expenditures and
substantial infrastructure dedicated to fire suppression, the annual area burned by wildfire...
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...
Controversial end member models for the growth and evolution of the Tibetan Plateau demand quantitative constraints of the lithospheric rheology. Direct determinations of bulk crustal rheology, however, remain relatively sparse. Here we use the flexural rebound of lacustrine shorelines developed during the Lingtong highstand around Siling Co, in central Tibet,...
Premise of research: A distinctive new species of osmundaceous fern, based on a permineralized trunk from
Lower Cretaceous deposits of Haida Gwaii (formerly the Queen Charlotte Islands) off the west coast of mainland
Canada, provides additional data for addressing the Mesozoic diversity and the overall pattern of phylogeny
for osmundaceous...
Premise of research. A new, morphologically distinct, anatomically preserved conifer assignable to the basal Cupressaceae, which was subject to arthropod infestation during life, has been discovered within a marine carbonate concretion from the Coniacian (Late Cretaceous) Eden Main locality of Vancouver Island, British Columbia. Methods. Specimens were studied from anatomical...
A mutational analysis was conducted to investigate the functions of the tobacco etch potyvirus VPgproteinase
(NIa) protein in vivo. The NIa N-terminal domain contains the VPg attachment site, whereas the
C-terminal domain contains a picornavirus 3C-like proteinase. Cleavage at an internal site separating the two
domains occurs in a subset...
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...