scholarly journals The McAbee flora of British Columbia and its relation to the Early-Middle Eocene Okanagan Highlands flora of the Pacific Northwest

2005 ◽  
Vol 42 (2) ◽  
pp. 151-166 ◽  
Author(s):  
Richard M Dillhoff ◽  
Estella B Leopold ◽  
Steven R Manchester
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Middle Eocene ◽  
Pollen Record ◽  
Separate Species ◽  
Early Oligocene ◽  
Pollen Types ◽  
The Republic ◽  
Okanagan Highlands ◽  
Angiosperm Pollen

Megafossils and pollen data are used to compare the flora found at the McAbee site, located near the town of Cache Creek, British Columbia, to six other well-collected Eocene lacustrine floras of Washington and western British Columbia. A diverse flora is found at McAbee consisting of at least 87 taxa. Gymnosperms are common, including sixteen separate species, 14 conifers and two ginkgos. A minimum of 67 angiosperm genera are represented in the flora, many yet to be described. The dominant dicotyledonous elements of the leaf assemblage at McAbee include Fagus (also represented by nuts and cupules) with Ulmus and representatives of the Betulaceae, especially Betula and Alnus. The confirmation of Fagus, also rarely found from sites at Princeton, British Columbia, and Republic, Washington, provides the oldest well-documented occurrence of the genus, predating the Early Oligocene records of Fagus previously reported for North America, Asia, and Europe. Data provided by pollen analysis broadens our knowledge of the McAbee flora. Angiosperm pollen typically predominates over gymnosperms with the Ulmoideae and Betulaceae being the most common angiosperm pollen types. Members of the Pinaceae dominate the gymnosperm pollen record. Paleoclimatic estimates for McAbee are slightly cooler than for the Republic and Princeton localities and thermophilic elements, such as Sabal found at Princeton or Ensete and Zamiaceae found at Republic are not known from McAbee.

Systematics and phytogeography of selected Eocene Okanagan Highlands plants

2005 ◽  
Vol 42 (2) ◽  
pp. 205-214 ◽  
Author(s):  
Melanie L DeVore ◽  
Kathleen B Pigg ◽  
Wesley C Wehr
Keyword(s):  
British Columbia ◽  
North America ◽  
North American ◽  
Middle Eocene ◽  
Rapid Evolution ◽  
Witch Hazel ◽  
South Central ◽  
The Republic ◽  
Okanagan Highlands ◽  
Early Radiation

The diverse Early to Middle Eocene Okanagan Highlands floras of south central British Columbia and northeastern Washington reflect a time of rapid evolution and the early radiation of many dicot families that are currently significant elements of temperate floras. Recent studies of the Republic, Washington flora (Klondike Mountain Formation) and related Okanagan floras in British Columbia have documented both the earliest, and sometimes the only, known fossil occurrences of genera. Today many once more widespread taxa are restricted, particularly to Asian and (or) eastern North American refugia. Examples include members of the families Betulaceae (birch, hazelnut), Rosaceae (rose), Hamamelidaceae (witch hazel), and the endemic Asian family Trochodendraceae. Earliest occurrences are noted for Neviusia (Rosaceae), Trochodendron (Trochodendraceae), Corylus and Carpinus (both Betulaceae). The first unequivocal leaf records of Corylopsis and Fothergilla (both Hamamelidaceae), and two new Eocene species of the extinct fruit Palaeocarpinus (Betulaceae) are also recognized. Today, Trochodendron and Corylopsis are restricted to Asia, whereas Neviusia and Fothergilla, genera with close Asian relatives, occur only in North America. Corylus johnsonii from Republic is most similar to the extant Asian species C. heterophylla, C. wangii, and C. ferox. Neviusia leaves from One Mile Creek near Princeton, British Columbia are more similar to N. cliftonii, an endemic from Mount Shasta, California, than to N. alabamensis of southeastern North America. A better documentation of the Okanagan Highlands floras is essential to our understanding of the evolution of North American temperate floras and the nature of Asian – North American disjunct taxa.

Paleogeographic evolution of the United States Pacific Northwest during Paleogene time

1987 ◽  
Vol 24 (8) ◽  
pp. 1652-1667 ◽  
Author(s):  
Paul L. Heller ◽  
Rowland W. Tabor ◽  
Christopher A. Suczek
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Middle Eocene ◽  
The United States ◽  
Oceanic Islands ◽  
Local Source ◽  
Second Phase ◽  
Early Oligocene ◽  
Basin Development ◽  
Major Transition

Paleogeographic reconstructions for Oregon and Washington during Paleogene time illustrate a major transition from a dominantly compressional (prior to middle Eocene time) to an extensional tectonic regime. This transition resulted in the development of three phases of Paleogene basin evolution in the United States Pacific Northwest. During the initial phase, basins formed along the continental margin during collision of oceanic islands. Sediments in these basins were derived from nearby orogenic highlands. The second phase of basin development began in middle Eocene time and consisted of rapid subsidence of individual basins that formed within a broad forearc region. Nonmarine basins that formed during this phase were caused by extension possibly associated with transcurrent faulting. Rapid sedimentation in both marine and nonmarine basins during this time consisted dominantly of sandstone derived from Cretaceous plutonic sources far to the east. The final stage of basin development was the modification of previous basin configurations by the growth of the Cascade volcanic arc, which was initiated in early Oligocene time. The rising Cascade Range diverted streams carrying eastern-derived material, thereby reducing overall sedimentation rates in the coastal basins and providing a local source of volcanic detritus.

Fagus (Fagaceae) fruits, foliage, and pollen from the Middle Eocene of Pacific Northwestern North America

2004 ◽  
Vol 82 (10) ◽  
pp. 1509-1517 ◽  
Author(s):  
Steven R Manchester ◽  
Richard M Dillhoff
Keyword(s):  
British Columbia ◽  
North America ◽  
Middle Eocene ◽  
Molecular Evidence ◽  
Secondary Vein ◽  
Early Oligocene ◽  
Fossil Evidence ◽  
Ca 50 ◽  
Northwestern North America

Fruits and leaves from the Middle Eocene of McAbee, British Columbia, and Republic, Washington, provide an earlier record for the genus Fagus than previously accepted for this member of the Fagaceae. The fruits are trigonal nuts borne within spiny four-valved cupules on long peduncles. The leaves are borne alternately on the twigs and are ovate to elliptic with craspedodromous secondary veins and simple teeth distributed one per secondary vein. The shale preserving these megafossils also contains dispersed pollen with morphology and ornamentation diagnostic of Fagus. Previously, the oldest Fagus occurrences confirmed by fruits were early Oligocene (ca. 32 Ma). The recognition of Middle Eocene (ca. 50 Ma) representatives helps to reduce the disparity between molecular evidence favoring Fagus as a primitive genus within Fagaceae, and fossil evidence, which had indicated older occurrences of Castanea and Quercus than Fagus.Key words: Eocene, Fagus, fossil, foliage, fruits, British Columbia.

Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: climates and ecosystems across an Eocene landscape

2005 ◽  
Vol 42 (2) ◽  
pp. 167-185 ◽  
Author(s):  
David R Greenwood ◽  
S Bruce Archibald ◽  
Rolf W Mathewes ◽  
Patrick T Moss
Keyword(s):  
British Columbia ◽  
North American ◽  
Deciduous Forest ◽  
Middle Eocene ◽  
Washington State ◽  
Leaf Margin ◽  
Forest Zone ◽  
Aquatic Fern ◽  
Equable Climate ◽  
Okanagan Highlands

The late Early to early Middle Eocene Okanagan Highlands fossil sites, spanning ~1000 km north–south (northeastern Washington State, southern British Columbia) provide an opportunity to reconstruct biotic communities across a broad upland landscape during the warmest part of the Cenozoic. Plant taxa from these fossil sites are characteristic of the modern eastern North American deciduous forest zone, principally the mixed mesophytic forest, but also include extinct taxa, taxa known only from eastern Asian mesothermal forests, and a small number of taxa restricted to the present-day North American west coast coniferous biome. In this preliminary report, paleoclimates and forest types are reconstructed using collections from Republic in Washington State, USA., and Princeton, Quilchena, Falkland, McAbee, Hat Creek, Horsefly, and Driftwood Canyon in British Columbia, Canada. Both leaf margin analysis (LMA) and quantitative bioclimatic analysis of identified nearest living relatives of megaflora indicated upper microthermal to lower mesothermal moist environments (MAT ~10–15 °C, CMMT > 0 °C, MAP > 100 cm/year). Some taxa common to most sites suggest cool conditions (e.g., Abies, other Pinaceae; Alnus, other Betulaceae). However, all floras contain a substantive broadleaf deciduous element (e.g., Fagaceae, Juglandaceae) and conifers (e.g., Metasequoia) with the bioclimatic analysis yielding slightly higher MAT than LMA. Thermophilic (principally mesothermal) taxa include various insects, the aquatic fern Azolla, palms, the banana relative Ensete, taxodiaceous conifers, Eucommia and Gordonia, taxa which may have occurred near their climatic limits. The mixture of thermophilic and temperate insect and plant taxa indicates low-temperature seasonality (i.e., highly equable climate).

Eocene Ginkgo leaf fossils from the Pacific Northwest

2002 ◽  
Vol 80 (10) ◽  
pp. 1078-1087 ◽  
Author(s):  
George E Mustoe
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Ginkgo Biloba ◽  
Middle Eocene ◽  
Washington State ◽  
North Central ◽  
Lacustrine Deposits ◽  
South Central ◽  
The Pacific ◽  
Ginkgo Leaf

Middle Eocene lacustrine deposits in south-central British Columbia and north-central Washington state preserve two types of Ginkgo leaves. A morphotype characterized by deeply divided multiple lobes is herein described as Ginkgo dissecta sp.nov. Leaves that are either undivided or shallowly divided into bilobate symmetry are indistinguishable from foliage of extant Ginkgo biloba Linnaeus. These fossils contradict the widely held belief that only a single Ginkgo species, Ginkgo adiantoides (Unger) Heer, inhabited Cenozoic forests.Key words: British Columbia, Eocene, fossil, Ginkgo adiantoides, Ginkgo biloba, Ginkgo dissecta, McAbee, Republic, Tertiary, Washington.

Palynology and geochronology of Eocene beds from Cheslatta Falls and Nazko areas, central British Columbia

1988 ◽  
Vol 25 (8) ◽  
pp. 1268-1276 ◽  
Author(s):  
G. E. Rouse ◽  
W. H. Mathews
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Late Eocene ◽  
Early Oligocene ◽  
Early Tertiary ◽  
International Boundary ◽  
Climatic Cooling ◽  
Warm Temperate ◽  
Subtropical Environment

Early Tertiary lavas and sediments were collected from two areas west and south of Prince George, British Columbia, and processed for K/Ar dating and palynoassemblages.Samples from Cheslatta Falls gave K/Ar dates of 36.5 and 37.7 Ma and yielded a palynoassemblage very similar to that from the Jackson Group in Alabama and Mississippi. This Late Eocene assemblage is interpreted as having developed in a humid subtropical environment, prior to a climatic cooling that, we believe, should be assigned to Early Oligocene time.The Tertiary lavas and sediments from the Nazko area, west of Quesnel, gave three Middle Eocene dates and over 60 species of palynomorphs. These correlate with other rocks and palynoassemblages of Kamloops Group equivalents that occur southward across the International Boundary and north to latitude 55°N. The paleoclimate was wet and in the range of very warm temperate to humid subtropical.

New Dinopanorpidae (Insecta: Mecoptera) from the Eocene Okanagan Highlands (British Columbia, Canada and Washington State, USA)

2005 ◽  
Vol 42 (2) ◽  
pp. 119-136 ◽  
Author(s):  
S Bruce Archibald
Keyword(s):  
British Columbia ◽  
Middle Eocene ◽  
Hind Wing ◽  
Washington State ◽  
Large Species ◽  
Far Eastern Russia ◽  
The Family ◽  
Okanagan Highlands ◽  
Far Eastern ◽  
Maritime Province

Six new species of the extinct family Dinopanorpidae (Mecoptera) are described in the new genus Dinokanaga gen. nov. from five Early (and early Middle?) Eocene Okanagan Highlands localities in British Columbia and Washington State. These are Dinokanaga hillsi sp. nov., D. wilsoni sp. nov., D. dowsonae sp. nov., D. andersoni sp. nov., D. sternbergi sp. nov., and D. webbi sp. nov. The family Dinopanorpidae is previously known only from a hind wing of Dinopanorpa megarche Cockerell, and an undescribed species of Dinopanorpa, both from the Paleogene of Primorye (Maritime Province) in Pacific coastal far-eastern Russia. The family includes mostly large species, with forewings up to 43 mm in length. Dinopanorpidae is particularly distinguished by a long R1 vein in both the fore- and hind wings, extending almost to the wing apex and bending posteriad distally. Their wings are mostly dark with light bands and spots; have many to extremely dense crossveins; and an expanded costal space in the basal quarter of the forewing, which is more developed in larger species. The rostrum is extended; the medigynium is without tongue-shaped structures.

Corella species in the American Pacific Northwest: distinction of C. inflata Huntsman, 1912 from C. willmeriana Herdman, 1898 (Ascidiacea, Phlebobranchia)

1981 ◽  
Vol 59 (8) ◽  
pp. 1493-1504 ◽  
Author(s):  
Gretchen Lambert ◽  
Charles C. Lambert ◽  
Donald P. Abbott
Keyword(s):  
British Columbia ◽  
Shallow Water ◽  
Pacific Northwest ◽  
Southern California ◽  
Comparative Morphology ◽  
Sea Surface ◽  
Separate Species

The solitary phlebobranch ascidian Corella inflata, originally described by Huntsman in 1912 but later synonymized with C. willmeriana Herdman, 1898, is now reinstated as a separate species based on comparative morphology of adults, sperm, and tadpoles. Corella inflata is probably largely or completely self-fertilizing, broods its eggs and embryos until well after hatching of the tadpole larvae, and is confined in its distribution to shallow-water (0.1–18 m depth) areas of northwestern Washington and British Columbia. Corella willmeriana appears to be both self- and cross-fertilizing, does not brood its eggs, and is more widespread in distribution, occurring from southern Alaska to southern California and at least as deep as 50 m; it is rarely encountered at the sea surface. The two Corella species differ morphologically from the European Corella parallelogramma and the Japanese C. japonica and C. japonica asamushi. Differential spawning latencies are discussed and the possibility that C. inflata evolved through stasipatric speciation is proposed.

Regional and local vegetation community dynamics of the Eocene Okanagan Highlands (British Columbia – Washington State) from palynology

2005 ◽  
Vol 42 (2) ◽  
pp. 187-204 ◽  
Author(s):  
Patrick T Moss ◽  
David R Greenwood ◽  
S Bruce Archibald
Keyword(s):  
British Columbia ◽  
Community Dynamics ◽  
Middle Eocene ◽  
Regional Distribution ◽  
Floristic Composition ◽  
Washington State ◽  
Depositional Environments ◽  
Limiting Factor ◽  
Palynological Analysis ◽  
Okanagan Highlands

Palynofloras from the middle Early to early Middle Eocene Okanagan Highlands (northern Washington State and southern British Columbia) are used to reconstruct vegetation across a broad upland Eocene landscape. In this preliminary report, forest floristic composition is reconstructed using palynological analysis of sediments from Republic, Washington; localities of the Allenby Formation in the Princeton region (Hospital Hill, One Mile Creek and Summers Creek Road), Hat Creek, McAbee, Falkland, Horsefly, and Driftwood Canyon, British Columbia. Wind-dispersed taxa were dominant in all samples, consistent with floras preserved in lacustrine and paludal depositional environments. Pseudolarix was dominant in five of the floras, but Abies (Falkland) or Ulmus (Republic Corner Lot site) were dominant in individual samples for some floras. Betulaceae were dominant for McAbee (Alnus) and Allenby Formation (Betula), matching megafloral data for these sites. Some taxa common to most sites suggest cool conditions (e.g., Abies, other Pinaceae; Alnus, other Betulaceae). However, all floras contained a substantive broad-leaved deciduous element (e.g., Fagaceae, Juglandaceae) and conifers (e.g., Metasequoia) indicative of mesothermal conditions. Palms were only abundant in the Hat Creek coal flora, with very low counts recorded for the Falkland, McAbee, and Allenby Formation sites, suggesting that they were rare in much of the landscape and likely restricted to specialized habitats. Thermophilic (principally mesothermal) taxa, including palms (five sites) and "taxodiaceous" conifers, may have occurred at their climatic limits. The limiting factor controlling the regional distribution of thermophilic flora, which include primarily wetlands taxa, may be either climatic or edaphic.

Vegetative Growth of Eorhiza arnoldii Robison and Person from the Middle Eocene Princeton Chert Locality of British Columbia

1994 ◽  
Vol 155 (5) ◽  
pp. 606-616 ◽  
Author(s):  
Ruth A. Stockey ◽  
Kathleen B. Pigg
Keyword(s):  
British Columbia ◽  
Vegetative Growth ◽  
Middle Eocene
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