The stratigraphical significance, evolutionary pathways and distribution patterns of Devonian (with emphasis on Middle Devonian)

No abstract

Jurassic and Cretaceous charophytes of Western Canada (Saskatchewan and Alberta) are known from two narrow stratigraphic intervals and parts of the Bathonian (Middle Jurassic) and Aptian (Early Cretaceous) sequences of the prairie sequences. Thirteen species are accounted for with, twelve from the Bathonian and three from the Aptian. The Bathonian assemblage is one of the richest worldwide, and it provides valuable insight on the earliest phase of the Jurassic-Early Cretaceous radiation of the group.

A new ostracode assemblage, DFr6, characterizes the uppermost Frasnian rock sequences in western Canada. The assemblage or biozone contains elements of both the Frasnian and Famennian ostracode sequences and seems to be intermediate between both faunas, which in main aspects are strikingly different in composition. Similarities between the Devonian ostracodes of western Canada and their time-equivalent faunas of the Russian Platform and adjoining areas suggest the presence of a vast paleobiogeographic faunal province that is distinctly set apart from a "paleo-Tethyan" province whose ostracode representatives are found in central Europe and North Africa.The lower DFr6 subassemblage is contained in the Jean-Marie Member of the Redknife Formation, with the upper DFr6 ostracodes occurring in its upper member and in the Kakisa Formation. Both formations form prominent but lithologically similar carbonate sequences in the southwestern corner of the Northwest Territories and adjoining areas, causing problems in correlations, in particular in subsurface studies. Ostracodes of the upper DFr6 subzone were also recovered from the dolomites of the Winterburn Group of northern Alberta.

No abstract