|
''Metasequoia foxii'' is an extinct redwood species in the family Cupressaceae described from numerous fossils of varying growth stage. The species is solely known from the Paleocene sediments exposed in central Alberta, Canada. It is one of three extinct species belonging to the redwood genus ''Metasequoia''. ==History and classification== The species is known from a very large number of attached and isolated plant sections ranging from new seedlings to a large upright partial stump, collected from two outcrops of the Paskapoo Formation exposed east of Red Deer in central Alberta.〔 The formation is composed of medium-grain buff to light gray sandstones interbedded with finer sandstones and mudstones lying at an almost flat level. The outcrop at the Munce’s Hill location, also known as One Jaw Gap, is heavily fractured which resulted in difficulty removing the fossils for study. A number of the larger specimens were photographed prior to removal from the outcrop face to aid in study. Present at the Munce’s Hill location was one large upright stump which Stockey, Rothwell and Falder interpreted as being preserved in situ. The fossils of the formation are preserved as coalified compressions which have been oxidized.〔 ''Metasequoia foxii'' was described from a selection of 10,147 fossils.〔 The group is composed of 3263 seeds, 1850 seedlings in various stages of development, the in situ trunk, 2536 branches and branchlets, 123 branchlets with pollen cones, and 2373 ovulate cones. The holotype specimen, number "UAPC-ALTA S28,476" is an isolated ovulate cone on a long stem. All the specimens studied are currently preserved in the paleobotanical collections housed at the University of Alberta.〔 The specimens were studied by paleobotanists Ruth A. Stockey of the University of Alberta in Edmonton, Alberta, Canada with Gar W. Rothwell and Amy B. Falder of the Ohio University in Athens, Ohio, USA. Stockey, Rothwell, and Falder published their 2001 type description for ''M. foxii'' in the ''International Journal of Plant Sciences''.〔 The etymology of the chosen specific name ''foxii'' is in recognition of vertebrate paleontologist Richard C. Fox from the University of Alberta, who suggested several fossil localities to the authors for study including the Munce’s Hill 〔(【引用サイトリンク】url=http://www.ags.gov.ab.ca/gis/map_converters/ats_degrees_converter.html )〕 and Gao mine sites.〔 ''M. foxii'' is one of three currently recognized extinct species in the genus ''Metasequoia'', which is now represented by the single living species ''M. glyptostroboides''. The species ''M. milleri'' is known only from the early Eocene Ypresian Allenby Formation near Princeton, British Columbia. Formerly up to 20 species of extinct ''Metasequoia'' were proposed, however the majority were synonymised into the form species ''M. occidentalis'' which is known from numerous sites in the northern hemisphere.〔 It has been suggested that M. occidentalis and M. glyptostroboides are in fact, the same species with just a slight evolutionary difference due to millions of years passing.〔D.A. Hänks, http://dawnredwood.org/COOL%20STUFF.htm〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metasequoia foxii」の詳細全文を読む スポンサード リンク
|