The Regional Buor-Kemus Flora
Before the middle Albian structural and associated landscape modification of the North Pacific Region gave rise to six paleofloristic-paleogeographic subregions (Verkhoyansk-Chukotka, Okhotsk-Chukotka, Anadyr-Koryak, Northern Alaska, Yukon-Koyukuk and Chignik) a single uniform Buor-Kemus flora existed. This widespread flora corresponds in age to the early, middle and, partially, late Albian. The VCSR volcanic upland and the AKSR coastal lowlands and plains were formed at the very end of the time that the Buor-Kemus flora existed: taphofloras of the Buor-Kemus type occur close to the base of sections in each of the six subregions. The Buor-Kemus florais not featured in any detail in this catalogue.
Correlation chart showing the relationship between the Buor-Kemus Flora and other floras of the North Pacific Region.
The Buor-Kemus flora is well studied in Northeastern Russia, being very diverse (over 150 species) and known from many localities. Plant remains have been collected from the following stratigraphic subdivisions: Buor-Kemus Formation of Zyrianka coalfield, the Kolyma River basin (Prinada, 1938; Samylina, 1960, 1964, 1967, 1974); Upper Ainakhkurgen Subformation and Chimchememel Formation of the Ainakhkurgen depression, the Bolshoi Anyui River basin (Filippova, 1975b; Samylina, 1974, 1976; Belyi, 1994); Umkuveem, Marakveem and Irvunei formations of the Umkuveem depression, and the Eropol River basin (Filippova, 1975b; Samylina, 1974, 1976); Middle and Upper Omsukchan subformations and Toptan Formation of the Omsukchan area, Magadan district (Samylina, 1976); Predgornaya Sequence of Koyachan Group, the Ichigem Ridge (Belyi, 1994); and from the Kresta Bay area in the eastern Chukotka (Samylina, 1976). The Toptan flora distinguished by Samylina (1976) based on a floristic assemblage from the Toptan Formation of the Omsukchan area also belongs to the Buor-Kemus flora.
Classical descriptions of the Buor-Kemus Flora and a complete list of its taxa have been published by Samylina (1964, 1967, 1974, 1976) and Filippova (1975b). In addition to abundant and diverse ferns and gymnosperms, very rare angiosperms occur in this flora, first appearing in Northeastern Asia. In three areas of the Buor-Kemus floral distribution the plant-bearing beds conformably overlie marine deposits with Aptian faunal remains (Samylina, 1988; Belyi, 1994). It is likely that the stratigraphic range of this flora includes not only the early–middle Albian (Samylina, 1974, 1988), but extends into part of the late Albian.
In composition and age, the Buor-Kemus Flora of Northeastern Russia is close to the Early Ginter Flora of the AKSR (Herman, 1999a) and Kukpowruk Flora of the NASR (Spicer and Herman, 2001)).
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Systematic composition of the Buor-Kemus flora (Northeastern Russia, Early to Late Albian; Samylina, 1974)
Marchantiopsida:
Thallites sp.
Equisetopsida:
Equisetites ex gr. bureiensis (Heer) Kryshtofovich
E. ramosus Samylina
Equisetites sp.
Polypodiopsida:
Osmunda cretacea Samylina
O. denticulata Samylina
O. serrulata Samylina
Osmunda sp. 1
Osmunda sp. 2
Osmundopsis efimovae Samylina
Gleichenites ? waltoni Seward
Birisia acutata Samylina
B. alata (Prynada) Samylina
B. onychioides (Vassilevskaya et Kara-Mursa) Samylina
Coniopteris arctica (Prynada) Samylina
C. bicrenata Samylina
C. brevifolia (Fontaine) Bell
C. compressa Vassilevskaya
C. dicksonioides Samylina
C. gracillima (Heer) Vassilevskaya
C. aff. ketovae Vassilevskaya
C. aff. maakiana (Heer) Prynada
C. nympharum (Heer) Vachrameev
C. saportana (Heer) Vachrameev
Adiantopteris gracilis (Vassilevskaya) Vassilevskaya
Arctopteris heteropinnula Kiritchkova
A. kolymensis Samylina
A. lenaensis Vassilevskaya
A. obtusipinnatus Samylina
A. rarinervis Samylina
Onychiopsis psilotoides (Stokes et Webb) Ward
Asplenium dicksonianum Heer
A. popovii Samylina
A. rigidum Vassilevskaya
Hausmannia cf. undulata Vassilevskaya
Polypodites polysorus Prynada
Acrostichopteris aff. parvifolia Fontaine
A. pluripartita (Fontaine) Berry
Acrostichopteris sp.
Cladophlebis acuta Fontaine
C. aff. arctica (Heer) Seward
C. argutula (Heer) Seward
C. gluschinskii Vassilevskaya
C. lobulata Samylina
C. pseudolobifolia Samylina
C. speranskae Samylina
C. virginensis Fontaine
Cladophlebis sp.
cf. Lobifolia lobifolia (Phill.) Rasskazova et E. Lebedev
Scleropteris verchojanensis Kiritchkova
Sphenopteris mclearnii Bell
Ginkgoales:
Ginkgo ex gr. adiantoides (Unger) Heer
G. angusticuneata Vassilevskaya
G. ex gr. concinna Heer
G. delicata Samylina
G. ex gr. huttonii (Sternberg) Heer
G. ex gr. lepida Heer
G. nana (Dawson) Bell
G. paradiantoides Samylina
G. polaris Nathorst
G. ex gr. sibirica Heer
G. singularis Samylina
Baiera ahnertii Kryshtofovich
Sphenobaiera biloba Prynada
S. ex gr. czekanowskiana (Heer) Florin
S. flabellata Vassilevskaya
S. ex gr. longifolia (Pom.) Florin
S. ex gr. pulchella (Heer) Florin
Leptostrobales:
Czekanowskia ex gr. rigida Heer
Phoenicopsis ex gr. angustifolia Heer
Leptostrobus marginatus Samylina
Cycadales:
Nilssonia comtula Heer
N. decursiva Samylina
N. aff. grossinervis Prynada
N. magnifolia Samylina
N. pilifera Samylina
N. schaumburgensis (Dunk.) Nathorst
N. aff. serotina Heer
Nilssonia sp.
Bennettitales:
Anomozamites arcticus Vassilevskaya
Anomozamites sp.
Neozamites verchojanensis Vachrameev
Nilssoniopteris prynadae Samylina
Williamsonia philatovii Turutanova-Ketova
Cycadophyta incertae sedis:
Butefia obliqua Samylina
Heilungia sangarensis Vassilevskaya
Taeniopteris lundgrenii Nathorst
T. platyrachis Samylina
Pinales:
Podozamites ex gr. corbinensis Bell
P. ex gr. eichwaldii Schimper
P. ex gr. lanceolatus (Lindl. et Hutt.) F. Braun
P. ex gr. minor (Prynada) Samylina
P. aff. tuvensis Teslenko
Pagiophyllum triangulare Prynada
Elatocladus manchurica (Yokoyama) Yabe
Cephalotaxopsis borealis Samylina
C. cf. intermedia Hollick
C. sangarensis Vassilevskaya
Cephalotaxopsis sp. cf. Cephalotaxus microphylla Sveshnikova et Budantsev
Florinia (?) borealis Sveshnikova et Budantsev
Pityophyllum ex gr. nordenskioldii (Heer) Nathorst
P. ex gr. staratschinii (Heer) Nathorst
Pityospermum brachypterum Samylina
P. nansenii Nathorst
P. cf. pachypterum Prynada
P. umbonatum Samylina
P. cf. yukonense Bell
Pityospermum sp.
Pityostrobus piceoides Samylina
Drepanolepis sp. 1
Drepanolepis sp. 2.
Schizolepis cretaceus Samylina
Sciadopitys sp.
Sequoia cf. concinna Heer
Sequoia sp. 1
Sequoia sp. 2
Athrotaxopsis grandis Fontaine
cf. Athrotaxites berryi Bell
Parataxodium sugoijensis Samylina
P. cf. wigginsii Arnold et Lowter
Desmiophyllum magnum (Samylina) Samylina
Pseudotorellia pulchella (Heer) Vassilevskaya
Pseudotorellia sp.
Sachalinella kolymensis (Kryshtofovich) Imchanitskaya
Magnoliopsida:
Ranunculicarpus quinquecarpellatus Samylina
Cercidiphyllum potomacensis (Ward) Vachrameev
Cinnamomoides ievlevii Samylina
Lindera minima Samylina
Nelumbites aff. minimus Vachrameev
Platanus (?)sp.
Protophyllum (?) sp.
Sapindopsis sp.
Crataegites borealis Samylina
C. borealis f. sinuosa Samylina
Dalbergites sp. 1
Dalbergites sp. 2
Celastrophyllum kolymensis Samylina
Celastrophyllum oppositifolia Samylina
C. aff. ovale Vachrameev
C. serrulatus Samylina
Celastrophyllum sp.
Araliaecarpum kolymensis Samylina
Ziziphoides sp.
Dicotylophyllum obliquum Samylina
D. zyrjankense Samylina
Sugoia opposita Samylina
Dicotylophyllum sp. 1 (Samylina, 1974)
Dicotylophyllum sp. 2 (Samylina, 1974)
Dicotylophyllum sp. 3 (Samylina, 1974)
Dicotylophyllum sp. 4 (Samylina, 1974)
Dicotylophyllum sp. A (Samylina, 1974)
Dicotylophyllum sp. B (Samylina, 1974)
Dicotylophyllum sp. C (Samylina, 1974)
Dicotylophyllum sp. D (Samylina, 1974)
Dicotylophyllum sp. E (Samylina, 1974)
Caricopsis compacta Samylina
C. laxa Samylina
Kenella filatovii Samylina
K. harrisiana Samylina
Rogersia (?) denticulata Samylina
Ievlevia dorofeevii Samylina
Carpolithes sp. 1 (Samylina, 1974)
Carpolithes sp. 2 (Samylina, 1974)
Carpolithes sp. 3 (Samylina, 1974)
Carpolithes sp. (Samylina, 1974)
Carpolithes sp. 5 (Samylina, 1974)
Samaropsis cirrifera Samylina
Mirella borealis Samylina
Mirella sp.
Stenorachis ex gr. lepida Seward
Stenorachis sp.
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