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.

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).

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.

Early Eocene (Ypresian) birds from the Okanagan Highlands, British Columbia (Canada) and Washington State (USA)

2019 ◽  
Vol 56 (8) ◽  
pp. 803-813
Author(s):  
Gerald Mayr ◽  
S. Bruce Archibald ◽  
Gary W. Kaiser ◽  
Rolf W. Mathewes
Keyword(s):  
British Columbia ◽  
North America ◽  
Fossil Record ◽  
Washington State ◽  
Fossil Birds ◽  
Early Eocene ◽  
Western North America ◽  
Postcranial Skeleton ◽  
The North ◽  
Okanagan Highlands

We survey the known avian fossils from Ypresian (early Eocene) fossil sites of the North American Okanagan Highlands, mainly in British Columbia (Canada). All specimens represent taxa that were previously unknown from the Eocene of far-western North America. Wings from the McAbee site are tentatively referred to the Gaviiformes and would constitute the earliest fossil record of this group of birds. A postcranial skeleton from Driftwood Canyon is tentatively assigned to the Songziidae, a taxon originally established for fossils from the Ypresian of China. Two skeletons from Driftwood Canyon and the McAbee site are tentatively referred to Coliiformes and Zygodactylidae, respectively, whereas three further fossils from McAbee, Blakeburn, and Republic (Washington, USA) are too poorly preserved for even a tentative assignment. The specimens from the Okanagan Highlands inhabited relatively high paleoaltitudes with microthermal climates (except Quilchena: lower mesothermal) and mild winters, whereas most other Ypresian fossil birds are from much warmer lowland paleoenvironments with upper mesothermal to megathermal climates. The putative occurrence of a gaviiform bird is particularly noteworthy because diving birds are unknown from other lacustrine Ypresian fossil sites of the Northern Hemisphere. The bones of the putative zygodactylid show a sulphurous colouration, and we hypothesize that this highly unusual preservation may be due to the metabolic activity of sulphide-oxidizing bacteria.

Wes Wehr dedication

2005 ◽  
Vol 42 (2) ◽  
pp. 115-117 ◽  
Author(s):  
S Bruce Archibald ◽  
Kathleen B Pigg ◽  
David R Greenwood ◽  
Steven R Manchester ◽  
Lisa Barksdale ◽  
...  
Keyword(s):  
British Columbia ◽  
Natural History ◽  
Washington State ◽  
Okanagan Highlands

We dedicate this issue to the memory of Wesley C. Wehr, former Affiliate Curator of Paleobotany, Burke Museum of Natural History and Culture, Seattle, Washington. Wes' contributions to paleontology, particularly in the Okanagan Highlands of Washington State and British Columbia; his influence on a generation of paleontologists (particularly paleobotanists) working in and coming from this region; and his warm friendship that brought together members of the scientific and arts communities were deeply influential, and will be fondly remembered.

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.

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.

Insect fossils in middle Eocene deposits from British Columbia and Washington State: faunal diversity and geological range extensions

1996 ◽  
Vol 74 (6) ◽  
pp. 1140-1157 ◽  
Author(s):  
Sheila D. Douglas ◽  
Ruth A. Stockey
Keyword(s):  
British Columbia ◽  
North America ◽  
New Records ◽  
Middle Eocene ◽  
Washington State ◽  
Fossil Insects ◽  
Geological Record ◽  
The World ◽  
Faunal Diversity ◽  
Insect Fossils

Fossil insects in the orders Coleoptera, Hymenoptera, Diptera, and Lepidoptera were examined from nine middle Eocene localities in British Columbia, Canada, and Washington State, U.S.A. Twenty-five taxa are described, with the majority classified into families. Specimens belonging to Bibionidae and Ichneumonidae were the most common. Almost half of the coleopteran specimens were isolated elytra and identification was not possible. Three of the insect families (Cantharidae, Arctiidae, Noctuidae) represent the earliest known occurrence of the taxa in the world geological record and seven families (Lucanidae, Cantharidae, Scoliidae, Pompilidae, Rhagionidae, Arctiidae, Noctuidae) are the earliest records in North America. Eleven of the families identified are new records for the middle Eocene of British Columbia – Washington State, bringing the diversity of fossil insects in the region to 28 families. Significant for the study of anthecology are new records for lepidopterans.

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.

Testing ecological release as a compensating mechanism for mass mortality in a keystone predator

2020 ◽  
Vol 637 ◽  
pp. 59-69 ◽  
Author(s):  
J Sullivan-Stack ◽  
BA Menge
Keyword(s):  
Community Dynamics ◽  
Limiting Factor ◽  
Sea Star ◽  
Top Predator ◽  
Oregon Coast ◽  
Ecological Release ◽  
Keystone Predator ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome

Top predator decline has been ubiquitous across systems over the past decades and centuries, and predicting changes in resultant community dynamics is a major challenge for ecologists and managers. Ecological release predicts that loss of a limiting factor, such as a dominant competitor or predator, can release a species from control, thus allowing increases in its size, density, and/or distribution. The 2014 sea star wasting syndrome (SSWS) outbreak decimated populations of the keystone predator Pisaster ochraceus along the Oregon coast, USA. This event provided an opportunity to test the predictions of ecological release across a broad spatial scale and determine the role of competitive dynamics in top predator recovery. We hypothesized that after P. ochraceus loss, populations of the subordinate sea star Leptasterias sp. would grow larger, more abundant, and move downshore. We based these predictions on prior research in Washington State showing that Leptasterias sp. competed with P. ochraceus for food. Further, we predicted that ecological release of Leptasterias sp. could provide a bottleneck to P. ochraceus recovery. Using field surveys, we found no clear change in density or distribution in Leptasterias sp. populations post-SSWS, and decreases in body size. In a field experiment, we found no evidence of competition between similar-sized Leptasterias sp. and P. ochraceus. Thus, the mechanisms underlying our predictions were not in effect along the Oregon coast, which we attribute to differences in habitat overlap and food availability between the 2 regions. Our results suggest that response to the loss of a dominant competitor can be unpredictable even when based in theory and previous research.

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