Paleocene aged beds of the Ravenscrag Formation exposed in the Big Muddy Valley of Southern Saskatchewan produce numerous plant fossils. Studies into these fossils last occurred in the 1930s. Studies into the contemporaneous Ravenscrag Butte flora of southwestern Saskatchewan have shown that the flora of these beds needed updating. Collections of specimens and stratigraphic sections were taken from the area.<p>
Forty species, including two new species and seven unknowns were identified.
<i>Elatocladus megasequoiae</i> n.sp. and <i>Corvirupestrobus adrielensis</i> n.sp. are both
Conifers, and <i>Corvirupestrobus</i> is also a new genus. Many species were previously
unknown in Ravenscrag Formation floras, including cf.<i>Lygodium</i> sp., <i>Thelypteris</i> sp.,
<i>Sparganium</i> sp.,<i> Paloreodoxites plicata </i> (Lesquereux) Knowlton, <i>Carya
antiquorum</i> Newberry and <i>Nordenskioldia borealis</i> Heer. Two new combinations are
proposed, transferring <i>Quercus praegroenlandica</i> Berry to <i>Fagopsiphyllum
praegroenlandicum</i> (Berry) n. comb. and <i>Harmsia hydrocotoloidea</i> McIver and Basinger to <i>Harmsvernia hydrocotoloidea</i> (McIver and Basinger) n. comb., with <i>Harmsvernia</i> a new genus.<p>
Three sub-floras are recognized for this flora. Sub-flora 1 is a conifer dominated
swamp sub-flora, common to many Paleocene localities. Sub-flora 2 is a conifer dominated sub-flora suspected of being from a drier environment than florule 1. Elements of sub-flora 1 appear in sub-flora 2 and vice versa, but relative abundances differ. There is little taxonomic overlap between sub-floras 1 and 2 with sub-flora 3. Sub-flora 3 is more typical of contemporaneous localities to the south such as those of the Bear Den Member of the Golden Valley Formation (Hickey 1977), whereas sub-floras 1 and 2 are more typical of northern localities, like the Genesee locality (Chandrasekharam 1974) and Koryak Formation (Golovneva 1994). The Big Muddy Valley occurs at the ecotone between the Arctic floras and the floras of the South.<p>
The taxonomy of Glyptostrobus from the Paleocene is revised as an appendix, written as a separate report. This revision is more extensive than for the other taxa of this study, utilizing materials from numerous other localities, including the Joffre Bridge Roadcut localities (Hoffman and Stockey 1999), the Smokey Tower localities (Christophel 1976) and the Buchanan Lake Formation (Basinger 1991).
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-01302009-155531 |
| Date | 03 February 2009 |
| Creators | Postnikoff, Andrew Corbin Lindsay |
| Contributors | Harms, Vernon, Cota-Sánchez, J. Hugo, Basinger, James F., Renaut, Robin W. |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-01302009-155531/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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