A fossil flower with in situ Pistillipollenites from the Eocene of British Columbia

1988 ◽  
Vol 66 (2) ◽  
pp. 313-318 ◽  
Author(s):  
Ruth A. Stockey ◽  
Steven R. Manchester
Keyword(s):  
British Columbia ◽  
Convergent Evolution ◽  
Middle Eocene ◽  
New Taxon ◽  
Floral Structure ◽  
Ubisch Bodies ◽  
Spherical Hollow

A single actinomorphic flower has been found in the Horsefly Mine Top Section (Middle Eocene) of British Columbia. The flower, 2.1 cm in diameter, has six sepals, probably a superior ovary, and six stamens, one opposite each sepal. The pollen is morphologically identical with that of the dispersed grain of Pistillipollenites macgregorii Rouse. Grains, 22 μm in diameter, have numerous gemmae supported by columellae and a finer ornamentation of nanoverrucae. The grains are triporate with gemmae around apertures. Spherical hollow Ubisch bodies indicative of a secretory tapetum underlie remains of tapetal membranes. The floral structure of this new taxon, Pistillipollianthus wilsonii gen. et sp. nov., is distinctly different from the only other Pistillipollenites-producing flower described from the Eocene of Texas. The current study indicates that Pistillipollenites grains identified in sediments from the Cretaceous to the Eocene probably represent pollen from different angiosperm families, and it adds to the evidence that this type of gemmate grain may have evolved several times through convergent evolution.

Sapindaceous flowers from the Middle Eocene Princeton chert (Allenby Formation) of British Columbia, Canada

1990 ◽  
Vol 68 (9) ◽  
pp. 2025-2034 ◽  
Author(s):  
Diane M. Erwin ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
Key Words ◽  
Developmental Stages ◽  
Middle Eocene ◽  
Anther Wall

Seventeen small, staminate flowers, 3.0–4.5 mm long × 1.0–1.5 mm wide, representing two developmental stages of the same type of flower have been recovered from the Middle Eocene Princeton chert locality of British Columbia. Some specimens are immature buds with overlapping perianth parts enclosing the stamens; others represent mature flowers with an open perianth. Flowers are pedicellate with a small flat receptacle bearing a perianth of at least three sepals and up to four petals. Five specimens show a three- to four-lobed rudimentary pistil surrounded by an intrastaminal nectary disk. The 10 stamens are included or barely exserted with nonconnate filaments, 1.2–2.0 mm long, attached by a slender connective to large dithecal anthers up to about 0.9 mm long that open by longitudinal slits. The anther wall is represented by a palisadelike endothecium composed of cells that are thick-walled and radially elongated relative to the long axis of the anther. Abundant in situ pollen is semitectate–columellate, tricolporate, subprolate to prolate, and prominently striated with equatorially bridged colpi. This fossil combines flower and pollen characteristics similar to those of the Sapindaceae, resembling most closely the tribe Dodonaeeae. Key words: Sapindales, Dodonaeeae, Tertiary, permineralization, flowers, pollen.

Fossil Mosses from the Bisaccate Zone of the Mid-Eocene Allenby Formation, British Columbia

1974 ◽  
Vol 11 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Marian Kuc
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Plant Tissues ◽  
Plant Remains ◽  
Lake Bottom ◽  
White Colour

New fossil taxa (Ditrichites fylesi, Muscites maycocki, M. ritchiei, Palaeohypnum jovet-asti and P. steerei); unnamed moss and moss-like fossils, detrital fragments of various plant tissues, and paleobotanical evidence of the bisaccate zone are described from the Middle Eocene Allenby Formation near Princeton, British Columbia. These remains occur in laminated, tuffaceous, silty and pyroclastic shale, deposited under lacustrine conditions.Detailed examination of the various laminae indicates that beds of white colour and composed of coarser silt grains are poor in fossils and could be related to periods of decreasing bioproduction; less silty and darker coloured beds are rich in macro- and microfossils and could be related to periods of extensive bioproduction. The rock features, lamination, and distribution of macrofossils indicate the slow and undisturbed accumulation of plant remains on a lake bottom.

Eocene age for Ag–Pb–Zn–Au vein and replacement deposits of the Kokanee Range, southeastern British Columbia

1992 ◽  
Vol 29 (1) ◽  
pp. 3-14 ◽  
Author(s):  
G. Beaudoin ◽  
J. C. Roddick ◽  
D. F. Sangster
Keyword(s):  
British Columbia ◽  
Middle Jurassic ◽  
Middle Eocene ◽  
Hanging Wall ◽  
Spatial Association ◽  
High Heat ◽  
Time Interval ◽  
Genetic Link ◽  
Metasedimentary Rocks ◽  
Magmatic Event

The Ag–Pb–Zn–Au vein and replacement deposits of the Kokanee Range, southeastern British Columbia, are hosted by the Middle Jurassic Nelson batholith and surrounding Cambrian to Triassic metasedimentary rocks in the hanging wall of the transcrustal Slocan Lake Fault, Field relations indicate that mineralization is younger than the Nelson batholith and a Middle Jurassic foliation in the Ainsworth area but coeval or older than Eocene unroofing of the Valhalla metamorphic core complex in the footwall of the Slocan Lake Fault. Lamprophyre and gabbro dykes are broadly coeval with mineralization and have biotite and hornblende K–Ar ages defining a short-lived Middle Eocene alkaline magmatic event between 52 and 40 Ma. An older, Early Cretaceous alkaline magmatic event (141 – 129 Ma) is possible but incompletely documented.K–Ar and step-heating 40Ar/39Ar analyses on hydrothermal vein and alteration muscovite indicate that hydrothermal fluids were precipitating vein and replacement deposits 58–59 Ma ago. Crosscutting relationships with lamprophyre dykes indicate the Kokanee Range hydrothermal system lasted for more than 15 Ma. Eocene crustal extension resulted in a high heat flow and structures which were probably responsible for hydrothermal fluid movement and flow paths.A 100 Ma time interval is documented between batholith emplacement and spatially associated mineralization, ruling out any genetic link between the two. Similar large age differences between granite intrusion and peripheral mineralization have recently been documented for two world-sea le Ag–Pb–Zn vein districts, which suggest that spatial association between granite and Ag–Pb–Zn mineralization is not sufficient to infer a genetic link.

scholarly journals New or previously unrecorded avian taxa from the Middle Eocene of Messel (Hessen, Germany)

Fossil Record ◽  
2000 ◽  
Vol 3 (1) ◽  
pp. 207-219 ◽  
Author(s):  
G. Mayr
Keyword(s):  
Middle Eocene ◽  
The Other ◽  
New Taxon ◽  
New Information ◽  
Wenn Sich

Three new or from this site previously unrecorded birds are described from the Middle Eocene of Messel (Hessen, Germany). <i>Serudaptus pohli</i> n. gen. n. sp. is a new taxon of the Pseudasturidae and is distinguished from the other species of this family by its short and stout tarsometatarsus and the long and strong claws. An isolated foot of a gruiform bird is assigned to <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) and would, if this assignment can be confirmed, demonstrate the existence of this species for a period of 23 million years. The proportions of the toes suggest that <i>Idiornis</i> cf. <i>itardiensis</i> was less cursorial than its next recent relatives, the Cariamidae. In addition thereto, an exceptionally well preserved skeleton of a sandcoleid bird (Coliiformes: Sandcoleidae) gives new information on the osteology and feathering of sandcoleid birds. The specimen resembles the genera <i>Eoglaucidium</i> and <i>Anneavis</i> but it has not been possible to assign it to one of these two genera with certainty. <br><br> Drei neue oder von dieser Fundstelle bisher nicht nachgewiesene Vögel werden aus dem Mittel-Eozän von Messel (Hessen, Deutschland) beschrieben. <i>Serudaptus pohli</i> n. gen. n. sp. ist ein neues Taxon der Pseudasturidae und unterscheidet sich von den anderen Arten dieser Familie durch den kurzen und gedrungenen Tarsometatarsus und die langen, kräftigen Krallen. Der isolierte Fuß eines gruiformen Vogels wird <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) zugeordnet und würde, wenn sich diese Zuordnung bestätigt, die Existenz dieser Art über einen Zeitraum von 23 Millionen Jahren zeigen. Die Zehenproportionen legen nahe, dass <i>Idiornis</i> cf. <i>itardiensis</i> weniger an eine laufende Lebensweise angepasst war als seine nächsten rezenten Verwandten, die Cariamidae. Darüber hinaus zeigt ein außergewöhnlich gut erhaltenes Skelett eines Vertreters der Sandcoleidae bisher unbekannte Einzelheiten der Osteologie und Befiederung dieser Familie. Das Exemplar ähnelt den Gattungen <i>Eoglaucidium</i> und <i>Anneavis</i>, konnte jedoch keiner der beiden Gattungen mit Sicherheit zugeordnet werden. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20000030110" target="_blank">10.1002/mmng.20000030110</a>

scholarly journals Prescribing practices of endocrine therapy for ductal carcinoma in situ in British Columbia

2018 ◽  
Vol 25 (2) ◽  
pp. 133 ◽  
Author(s):  
A.T. Chaudhry ◽  
T.A. Koulis ◽  
C. Speers ◽  
R.A. Olson
Keyword(s):  
British Columbia ◽  
Endocrine Therapy ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Population Based ◽  
Cox Regression Analysis ◽  
Treatment Centre ◽  
Er Status

Purpose The mainstay of treatment for ductal carcinoma in situ (dcis) involves surgery in the form of mastectomy or lumpectomy. Inconsistency in the use of endocrine therapy (et) for dcis is evident worldwide. We sought to assess the variation in et prescribing for patients with dcis across a population-based radiotherapy (rt) program and to identify variables that predict its use.Methods Data from a breast cancer database were obtained for women diagnosed with dcis in British Columbia from 2009 to 2014. Associations between et use and patient characteristics were assessed by chi-square test and multilevel multivariate logistic regression. The Kaplan–Meier method, with propensity score matching and Cox regression analysis, was used to assess the effects of et on overall survival (os) and relapse-free survival (rfs).Results For the 2336 dcis patients included in the study, et use was 13% in dcis patients overall, and 17% in patients with estrogen receptor–positive (er+) tumours treated with breast-conserving surgery and rt. Significant variation in et use by treatment centre was observed (range: 8%–23%; p < 0.001), and prescription of et by individual oncologists varied in the range 0%–40%. After controlling for confounding factors, age less than 50 years [odds ratio (or): 1.72; p = 0.01], treatment centre, er+ status (or: 5.33; p < 0.001), and rt use (or: 1.77; p < 0.001) were significant predictors of et use. No difference in os or rfs with the use of et was observed.Conclusions In this population-based analysis, 13% of patients with dcis in British Columbia received et, with variation by treatment centre (8%–23%) and individual oncologist (0%–40%). Age less than 50 years, er+ status, and rt use were most associated with et use.

scholarly journals Triassic Wood from the Gordon Valley, Central Transantarctic Mountains, Antarctica

IAWA Journal ◽  
1995 ◽  
Vol 16 (2) ◽  
pp. 111-126 ◽  
Author(s):  
Georgina M. Dei Fueyo ◽  
Edith L. Taylor ◽  
Thomas N. Taylor ◽  
N. Rubén Cúneo
Keyword(s):  
Middle Triassic ◽  
Fossil Wood ◽  
New Taxon ◽  
Axial Parenchyma ◽  
Transantarctic Mountains ◽  
The Antarctic

Wood from an in situ permineralized forest from the Middle Triassic of Gordon Valley (Queen Alexandra Range, central Transantarctic Mountains) in Antarctica is described as a new taxon, Approximately 100 trunks in growth position are present at the site; they range from 13-61 cm in diameter and suggest that some of the trees were up to 20 m tall, Pits in the radial walls of the tracheids are of the abietinean type, Rays are uniseriate and 1-9 cells high; cross fields include one to two pits that appear to be simple, Axial parenchyma is absent. Pith and cortex are not preserved. The Antarctic wood is compared with existing fossil wood types from Antarctica and other parts of Gondwana. Although the fossil wood shares a number of characteristics with the Podocarpaceae, it differs from any existing genera and is described as a new taxon, Jeffersonioxylon gordonense.

scholarly journals A New Cypselomorph Bird from the Middle Eocene of Germany and the Early Diversification of Avian Aerial Insectivores

The Condor ◽  
2005 ◽  
Vol 107 (2) ◽  
pp. 342-352 ◽  
Author(s):  
Gerald Mayr
Keyword(s):  
Phylogenetic Analysis ◽  
Middle Eocene ◽  
Sister Group ◽  
Food Competition ◽  
Early Miocene ◽  
New Taxon ◽  
Insectivorous Birds ◽  
Dominant Group ◽  
Early Diversification ◽  
Aerial Insectivores

Abstract A new taxon of the Cypselomorphae—the clade including nightjars, potoos, owlet-nightjars, and apodiform birds—is described from the middle Eocene of Messel in Germany. Phylogenetic analysis of 49 characters shows Protocypselomorphus manfredkelleri gen. et sp. nov. to be the sister group of all other cypselomorph taxa, although this placement was not robust to bootstrapping. As evidenced by its swift-like beak, long forearm, and reduced feet, P. manfredkelleri was hawking insects on the wing. Thus it adds a distinctive new taxon to the already diverse assemblage of Paleogene aerial insectivores, all of which belong to the Cypselomorphae. This strongly contrasts with the extant avifauna where many aerial insectivores belong to songbirds, and among the insectivorous cypselomorph taxa only swifts and nightjars are species rich and widely distributed. The diversity of aerial insectivores among the Cypselomorphae may have been reduced by food competition with songbirds, which do not become the dominant group of insectivorous birds before the early Miocene. Una Nueva Ave Cipselomorfa del Eoceno Medio de Alemania y la Diversificación Temprana de las Aves Insectívoras Aéreas Resumen. Se describe un nuevo taxón de Cypselomorphae, el clado que incluye a las familias Caprimulgidae, Nyctibiidae, Aegothelidae y a las aves apodiformes, del Eoceno medio de Messel en Alemania. Un análisis filogenético de 49 caracteres muestra que Protocypselomorphus manfredkelleri gen. et sp. nov. es el grupo hermano de los demás taxa de cipselomorfos, aunque esta posición no fue apoyada por el análisis de bootstrap. Como lo evidencia su pico tipo vencejo, antebrazo largo y patas pequeñas, P. manfredkelleri cazaba insectos al vuelo. Así, este hallazgo añade un nuevo taxón al grupo ya diverso de los insectívoros aéreos del Paleógeno, todos los cuales pertenecen al grupo de los cipselomorfos. Esto contrasta fuertemente con la avifauna actual, en que muchos insectívoros aéreos pertenecen al grupo de los paseriformes, mientras que de los taxa de insectívoros cipselomorfos sólo los apodiformes y caprimúlgidos presentan alta diversidad específica y se encuentran ampliamente distribuidos. La diversidad de los insectívoros aéreos en los cipselomorfos pude haberse reducido debido a la competencia por alimento con las aves paseriformes, las cuales no se transforman en el grupo dominante de aves insectívoras sino hasta el Mioceno temprano.

Eocene paleo-physiography and drainage directions, southern Interior Plateau, British Columbia

2005 ◽  
Vol 42 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Selina Tribe
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Regional Scale ◽  
River Valley ◽  
Coast Mountains ◽  
Base Level ◽  
The North ◽  
Bedrock Geology ◽  
River Valleys ◽  
Early Cenozoic

A map of reconstructed Eocene physiography and drainage directions is presented for the southern Interior Plateau region, British Columbia south of 53°N. Eocene landforms are inferred from the distribution and depositional paleoenvironment of Eocene rocks and from crosscutting relationships between regional-scale geomorphology and bedrock geology of known age. Eocene drainage directions are inferred from physiography, relief, and base level elevations of the sub-Eocene unconformity and the documented distribution, provenance, and paleocurrents of early Cenozoic fluvial sediments. The Eocene landscape of the southern Interior Plateau resembled its modern counterpart, with highlands, plains, and deeply incised drainages, except regional drainage was to the north. An anabranching valley system trending west and northwest from Quesnel and Shuswap Highlands, across the Cariboo Plateau to the Fraser River valley, contained north-flowing streams from Eocene to early Quaternary time. Other valleys dating back at least to Middle Eocene time include the North Thompson valley south of Clearwater, Thompson valley from Kamloops to Spences Bridge, the valley containing Nicola Lake, Bridge River valley, and Okanagan Lake valley. During the early Cenozoic, highlands existed where the Coast Mountains are today. Southward drainage along the modern Fraser, Chilcotin, and Thompson River valleys was established after the Late Miocene.

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