Rolf W. Mathewes

Rolf W. Mathewes
Simon Fraser University · Department of Biological Sciences

BSc, PhD

About

178
Publications
32,715
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6,547
Citations
Citations since 2016
17 Research Items
1603 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250

Publications

Publications (178)
Article
Full-text available
In eastern Beringia (unglaciated Alaska and western Yukon), the Pleistocene-Holocene transition was characterised by rapid changes in plant, insect and mammal communities as the mammoth steppe ecosystem was replaced, first by shrub tundra and later boreal forest. These changes indicate a transition from well drained terrain with deep active layers...
Article
Full-text available
In order to better understand the potential effects of climatic change on forest cover during and after the Little Ice Age (ad 1550 to 1880), a high-elevation cirque Lake (Wildsee am Ruhestein) was cored and analysed using continuous plant macrofossil analysis, supplemented by standard pollen analysis. The plant macrofossil record provides local in...
Article
559 Zootaxa 5100 (4): 559-572 https://www.mapress.com/zt/ Abstract We revise the subfamily Zeuneropterinae (Orthoptera, Ensifera) and treat it as the family Palaeorehniidae Zeuner stat. nov. We restore the late Eocene Palaeorehnia Cockerell from Florissant, Colorado, USA to the taxon and describe two new genera and species in it: Ypopteron nicola n...
Article
A large collection (49 specimens) of early Eocene Fraxinus (ash) samaras enabled us to evaluate whether or not more than one species was present at the Quilchena fossil site. Analysis of living ashes indicates that morphology of the samara tips is sometimes cited as a taxonomic criterion, and sometimes assumed to be due to intraspecific variation....
Article
The osmylid subfamily Protosmylinae is revised based on our emended diagnosis: Petrushevskia Martynova, 1958 and Mesosmylidus Jepson et al., 2012 are excluded (both considered Osmylidae incertae sedis), and Sogjuta Martynova, 1958 is transferred to it from the Mesosmylininae. The late Eocene genus Protosmylus Krüger, 1913 is considered a junior syn...
Article
We describe the Cephalozygoptera, a new, extinct suborder of Odonata, composed of the families Dysagrionidae and Sieblosiidae, previously assigned to the Zygoptera, and possibly the Whetwhetaksidae n. fam. The Cephalozygoptera is close to the Zygoptera, but differs most notably by distinctive head morphology. It includes 59 to 64 species in at leas...
Article
Full-text available
We describe the Cephalozygoptera, a new, extinct suborder of Odonata, composed of the families Dysagrionidae and Sieblosiidae, previously assigned to the Zygoptera, and possibly the Whetwhetaksidae n. fam. The Cephalozygoptera is close to the Zygoptera, but differs most notably by distinctive head morphology. It includes 59 to 64 species in at leas...
Article
The Northwest Coast of Canada was likely an important location for glacial refugia in the Late Pleistocene. Recently, a caribou (Rangifer tarandus) antler fragment was reported from Graham Island dating prior to the Fraser Glaciation (MIS 3; 48,200–45,200 cal yr BP). The high carbon and nitrogen stable isotope values found in the bulk collagen samp...
Article
Full-text available
Kilgii Gwaay is an early Holocene archaeological wet site located in the intertidal zone of Ellen Island in the southern Haida Gwaii archipelago of coastal British Columbia, Canada. The Kilgii site includes one of the oldest shell middens in western North America and provides evidence of early maritime adaptations by humans. Radiocarbon-dated cultu...
Article
Paleogene sediments of the Huntingdon Formation, a correlative to the Chuckanut Formation of neighboring Washington State, USA, are exposed in the greater Vancouver area, British Columbia, Canada. Palynology and plant macrofossils suggest the Kanaka Creek section is Paleocene rather than Eocene in age. Detrital zircon dating is less decisive, yet i...
Article
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...
Article
The basal portion of a fossil caribou antler from Graham Island is the only evidence of large terrestrial vertebrates older than the Fraser (late-Wisconsin) glaciation on Haida Gwaii. This antler has been radiocarbon dated three times by different laboratories and all ages fall within the mid-Wisconsin Olympia Interglaciation (Marine Isotope Stage...
Article
Most major modern families of Hymenoptera were established in the Mesozoic, but the diversifications within ecologically key trophic guilds and lineages that significantly influence the character of modern terrestrial ecosystems – bees (Apiformes), ants (Formicidae), social Vespidae, parasitoids (Ichneumonidae), and phytophagous Tenthredinoidea – w...
Article
A partial skeleton of a bison was recovered during residential house construction in Whitehorse, Yukon, Canada. The specimen represents a young (estimated 6 year old) bison individual that died, was partially scavenged by carnivores, and subsequently buried by calcareous silt sediment in a pond or small lake during the middle Holocene, ~5400 years...
Article
Full-text available
Our study combines new geological and paleoecological information to reconstruct the glacial history and terrestrial paleoenvironments on Haida Gwaii during the advance phase of the Fraser glaciation (Marine Isotope Stage 2). At Cape Ball on eastern Graham Island, five accelerator mass spectrometry radiocarbon ages ranging from 23,200±280 to 26,650...
Article
The Quilchena fossil locality is dated (51.5 ± 0.4 Ma) to the Early Eocene Climatic Optimum (EECO), and is reconstructed as the warmest and wettest of the Early Eocene upland sites from the Okanagan Highlands of British Columbia and northern Washington State. Mean annual temperature (MAT) is estimated from leaf margin analysis, using 55 dicot morph...
Article
Full-text available
The Quilchena fossil locality is dated (51.5 ± 0.4 Ma) to the Early Eocene Climatic Optimum (EECO), and is reconstructed as the warmest and wettest of the Early Eocene upland sites from the Okanagan Highlands of British Columbia and northern Washington State. Mean annual temperature (MAT) is estimated from leaf margin analysis, using 55 dicot morph...
Article
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Sea cliffs at Cape Ball on Graham Island, British Columbia, expose a thick sequence of Pleistocene sediments deposited during at least two glaciations. In sequence, from the base of the section, the units are (1) stony mud, (2) till, (3) silt, sand, and peat, (4) stony mud, (5) laminated sand and silt, (6) cross-bedded sand, and (7) till. Of specia...
Article
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Garry oak (Quercus garryana) ecosystems are listed as "at-risk" or endangered throughout their global range. In Canada, they are an umbrella for over one hundred species that are endangered to some degree. In order to effectively recover or allow these species to persist where possible, we must understand the ecological processes essential to their...
Article
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Significance Elevated CO 2 combined with globally warm temperatures in the Eocene make its climate ideal for understanding modern global warming and its biotic consequences. Globally low temperature seasonality—the relationship between winter and mean annual temperatures—has been proposed as key to differential Eocene biodiversity and community pat...
Article
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Depositional evidence of Early Pleistocene glaciations in British Columbia are documented at only a few sites. Near Kelowna, in southern British Columbia, a construction project exposed glacial sediments beneath Lambly Creek Basalt, providing a minimum age for this glaciation. The basalt is composed of a number of flows yielding ages that range fro...
Article
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Several birch bark containers and other birch bark artifacts made by prehistoric First Nations have been encountered during archaeological excavations on the Canadian Plateau of British Columbia. From these discoveries, it is apparent that birch bark technologies were of major importance to First Nations, yet little attention has been paid to them...
Article
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Three new species of Pipunculidae (Diptera) are described (one named), from the early Eocene (Ypresian) Okanagan Highlands of British Columbia, Canada and Washington State, United States of America: Metanephrocerus belgardeae new species from Republic, Washington; and Pipunculidae species A and Pipunculinae species A from Quilchena, British Columb...
Article
Haida Gwaii (formerly Queen Charlotte Islands) is an archipelago on the outer central coast of British Columbia. Drizzle Bog on Graham Island is a Sphagnum-dominated peatland selected for a multiproxy palaeoecological analysis using pollen, spores and other microfossils to see whether climatic changes such as the Mediaeval Climate Anomaly' (MCA), L...
Article
Palaeoecological records of species richness spanning time intervals over which climate variables have shifted relative to one another can help reduce issues of colinearity that might affect our understanding of patterns of species richness. Fossil pollen assemblages have the potential to serve as a proxy for past plant richness because they record...
Article
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The scorpionfly (Mecoptera) superfamily Panorpoidea underwent an Eocene radiation, replacing the extinct Mesozoic orthophlebiid grade and reaching its greatest family-level diversity: Panorpidae, Panorpodidae, Austropanorpidae, Holcorpidae, Dinopanorpidae, and a new family proposed here, the Eorpidae. Only the Panorpidae and Panorpodidae survived t...
Article
We test Janzen's (1967) hypothesis that the low temperature seasonality in the modern tropics accounts for increased local species turnover (beta diversity) across montane landscapes relative to those of the more seasonal Temperate Zone. In the Eocene, low seasonality extended beyond the hot tropics to Polar Regions, therefore, its effects on monta...
Article
Pollen and conifer stomata analyses of lake sediments from Hippa Island on the north coast of British Columbia were used to reconstruct the vegetation history of this small hypermaritime island. Between 14,000 and 13,230 cal yr BP, the island supported diverse herb–shrub communities dominated by Cyperaceae, Artemisia and Salix. Pinus contorta and P...
Conference Paper
Background/Question/Methods Haida Gwaii is an archipelago of about 150 islands, located 80 km offshore of mainland British Columbia. Proximity to the Pacific Ocean moderates the climate of these islands, producing a hypermaritime environment that is characterized by cool summers, abundant fog, and very wet winters and that supports a mosaic of co...
Article
In 1968, a child's cranium was recovered from the banks of a northern Canadian river and held in a trust until the "cold case" was reopened in 2005. The cranium underwent reanalysis at the Centre for Forensic Research, Simon Fraser University, using recently developed anthropological analysis, "bomb-pulse" radiocarbon analysis, and forensic DNA tec...
Conference Paper
The Indianpoint section, 90 km southeast of Prince George, presents a >25 ka record of paleoenvironmental changes from non-glacial MIS 3 time to just before Late Wisconsinan (MIS2) ice from the Cordilleran Ice Sheet overran the site. Detailed plant and insect macrofossil and pollen analyses were carried out on a 5-6 m thick fine-grained unit. It re...
Article
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During construction of a road cut related to the Westside Road Interchange Project in West Kelowna, British Columbia, a till was encountered below one of the Lambly Creek valley basalts. The basalts are composed of a number of flows, ranging in age from 0.97 +- 0.05 Ma to 1.62 +-0.25 Ma based on new and available 40Ar/39Ar dating of basalt ground m...
Article
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The Early Eocene Okanagan Highlands series of lacustrine shale and coal deposits, in far western North America, constitutes a significant group of fossil sites with exceptional preservation of a diverse suite of organisms (Lagerstätten). With contemporaneous basins arrayed across about 1000 kilometres of southern British Columbia and northern Washi...
Article
Fossil arctic ground squirrel (Spermophilus parryii) middens were recovered from ice-rich loess sediments in association with Sheep Creek-Klondike and Dominion Creek tephras (ca 80 ka) exposed in west-central Yukon. These middens provide plant and insect macrofossil evidence for a steppe-tundra ecosystem during the Early Wisconsinan (MIS 4) glacial...
Poster
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Early Eocene land bridges allowed numerous plant and animal species to cross between Europe and North America via the Arctic. While many that were suited to prevailing cool Arctic climates would have been able to cross throughout much of this period, others would have found dispersal opportunities only during limited intervals when their requiremen...
Article
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Early Eocene land bridges allowed numerous plant and animal species to cross between Europe and North America via the Arctic. While many species suited to prevailing cool Arctic climates would have been able to cross throughout much of this period, others would have found dispersal opportunities only during limited intervals when their requirements...
Article
The postglacial history of vegetation in the Yale area of the lower Fraser River Canyon is described from sediments of two lakes using percentage pollen analysis supplemented with macrofossil evidence and radiocarbon dating. Deposition of postglacial sediments, ranging from basal clays to gyttjas, began about 11 500 y B.P. Three distinct pollen ass...
Article
Pollen and spore percentages and concentrations were determined from six peaty zones about 24500 radiocarbon years old at the Point Grey sea cliffs. All samples are dominated by nonarboreal pollen, especially Cyperaceae of local origin and Gramineae. Analysis of 'indicator pollen' suggests that two floristic elements were present, a local wetland c...
Article
Four new radiocarbon dates spanning the period of 10 740 + 395 to greater than 30 000 BP from a core taken from the bed of a high-level lake in the Saddle Hills of northwestern Alberta suggest that these hills escaped glacial overriding during late Wisconsinan glaciation.
Article
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Ash-grade Bridge River tephra, identified as such on the basis of shard habit, modal mineralogy, and composition of ilmenite, occurs in sedimentary cores from three lakes located to the south of the previously documented plume and necessitates a significant enlargement of the fallout area of that tephra in southwestern British Columbia.These new, m...
Article
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A sediment core from a pond on the Alberta Plateau in the Peace River district of British Columbia was studied using pollen analysis and radiocarbon dating. Percentage and influx diagrams were produced, and radiocarbon dates were corrected to calendar years to calculate the sedimentation rate. The 231 cm core terminated in clay, and a basal date of...
Article
The stratigraphic relationships of late-glacial and Holocene sediments exposed in sea cliffs at Cape Ball on the Queen Charlotte Islands are summarized, based on section descriptions and 13 radiocarbon dates on wood, peat, and marine pelecypod shells. One peat bed dated at 12 400 ± 100 years BP (GSC-3112) to 10 200 ± 90 BP (GSC-3159) was investigat...
Article
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A reconnaissance study of Quaternary sediments exposed in coastal bluffs on eastern Graham Island has revealed the presence of two major till units, each of which is underlain by glaciomarine stony mud, outwash sand and gravel, and laminated to massive silt and sand of undetermined origin. Sediment units below the surface drift are older than the r...
Article
A 60 cm long sediment core from Deer Lake, Burnaby, British Columbia was analyzed palynologically and geochemically in order to trace the effects of human disturbances since settlement. A settlement horizon was identified at 42.5 cm (ca. 1892) by pollen analysis. Declines in the percentages of coniferous tree species are mirrored by rapid increases...
Article
Accelerator mass spectrometry was used to test whether part of eastern Graham Island was ice free at the height of late Wisconsin glaciation on mainland British Columbia. An accelerator radiocarbon date of 14 700 ± 700 years on a small twig conforms with two conventional dates that suggested that the Cape Ball region of Graham Island was deglaciate...
Article
Seven samples of peat or wood were collected from four small sedimentary basins on Anthony Island. Elevations of these sites range between 31.1 and 2.5 m above mean sea level. Radiocarbon dates from these indicate that sea level has not exceeded 31.1 m since 12 300 years ago. Furthermore, sea level has been less than 12.7 m above mean sea level sin...
Article
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Nazko cone, located in central British Columbia at the eastern end of the Anahim Volcanic Belt, is the product of at least three episodes of Quaternary volcanic activity. An eroded Pleistocene subaerial flow at the base of the pile is overlain by a subglacial mound of hyaloclastite that is, in turn, partly covered by a younger composite pyroclastic...
Article
Chilhil, Phair, Fishblue, and Horseshoe lakes in the southern interior of British Columbia were cored and analyzed for pollen. Phair Lake was also examined for plant macrofossils and aquatic molluscs. Two dated volcanic tephras (Mazama and Bridge River) are present in three of the four lakes and, together with radiocarbon dates, provide an absolute...
Article
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Debris flow deposits of Chicago Creek and the sediment, pollen, and macrofossil records of Seeley Lake were studied to elucidate the Holocene history of the northwest flank of the Rocher Déboulé Range near Hazelton, British Columbia.The Chicago Creek drainage has experienced numerous rockfalls, debris slides, and debris flows. A large debris flow c...
Article
Three new radiocarbon dates from two lakes near Yale, B.C. establish that ice-free conditions existed in parts of the Lower Fraser Canyon as early as 11 430 ± 150 B.P. A volcanic ash layer found in both lakes is considered to have come from the Mount Mazama eruption, based on a radiocarbon date from Squeah Lake. Mention is made of the problematic r...
Article
To investigate postglacial environmental changes in southeastern British Columbia, subfossil pollen was analyzed from Eagle Lake, Mount Revelstoke National Park. Palynological evidence suggests that during the early Holocene, Eagle Lake was surrounded by an open forest. The pollen assemblage indicates that climatic conditions were warmer and drier...
Article
Thirty surface sediment samples were collected from Marion Lake to establish the present-day distribution patterns of potential plant macrofossils, with emphasis on remains derived from upland species. Sample sites could be separated into three distinct groups on the basis of their macrofossil representation: offshore sites, west shore sites, and e...
Article
Comparisons between current vegetation patterns and deposition of modern pollen and plant macroremains in a saline lake basin on the northern Great Plains are used to assess the value of plant remains as indicators of past local vegetation dynamics and lake-level changes. Results indicate that both modern pollen spectra and assemblages of plant mac...
Article
Full-text available
Surficial sediment samples from 42 lakes, distributed from sea level to alpine elevations of coastal British Columbia and northwest Washington, were analyzed for pollen and spores. Pollen analysis revealed characteristic differences among the assemblages of the Coastal Western Hemlock, Mountain Hemlock, and Engelmann Spruce – Subalpine Fir biogeocl...
Article
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Two years of aerial pollen trapping at two lakes surrounded by coniferous forest are summarized. Most of the annual pollen and spore deposition occurs between February and May (86%), followed by 10% during the summer, and 4% during the fall – winter nonflowering period. Annual aerial influx is very similar at both Marion and Surprise lakes, ca. 500...
Article
Pollen analysis and radiometric dating of sediment cores from two lakes in the Saddle Hills, Peace River district, Alberta, were used to investigate postglacial vegetation and climatic change. A poplar – willow – sage – grass – sedge zone began about 11 700 ± 260 years BP. A distinct pine and spruce rise indicates the local presence of conifers. Pe...
Article
The forest history around Marion Lake in southwestern British Columbia is reconstructed using plant macrofossil analysis. A comparison with a previous reconstruction based on pollen and spore analysis reveals a good correspondence between pollen and macrofossil zones. Significant improvements in the reconstruction of forest history are possible by...
Article
Full-text available
Transfer functions for converting pollen frequencies to estimates of mean July temperature and mean annual precipitation were applied to fossil pollen data from a sediment core in Marion Lake. The paleotemperature curve shows low July temperatures near 14 °C at the base of the core at about 12 000 before present (B.P.), rising rapidly between 10 40...
Article
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The pollen morphology of four species of Myriophyllum from northwestern North American populations is described from studies using bright-field, interference-contrast, and scanning electron microscopy. Results indicate that M. verticillatum, M. heterophyllum, and M. hippuroides can be determined to species on the basis of pollen morphology. Myrioph...
Article
Six morphological types of Polemonium pollen are described, including P. micranthum which is the only taxon considered to be consistently identifiable to species. A key to the pollen types as seen in light microscopy is presented along with light and scanning electron micrographs of each type. The palynological evidence supports the taxonomic treat...
Article
Full-text available
The postglacial vegetation history of the University of British Columbia Research Forest was investigated using percentage and absolute pollen analysis, macrofossil analysis, and radiocarbon dating. A marine silty clay deposit records the oldest (12 690 ± 190 years before present (B.P.)) assemblage of terrestrial plant remains so far recovered from...
Poster
Full-text available
The Early Eocene was a time of globally warm and equable climates, and is also noted for the appearance of many modern plant and insect genera, and as the time when terrestrial communities began to take on their modern form. A series of Early Eocene lake lagerstätten collectively called the Okanagan Highlands were deposited in basins from central B...
Article
Full-text available
Differences between pollen assemblages obtained from lacustrine and terrestrial surface sediments may affect the ability to obtain reliable pollen-based climate reconstructions. We test the effect of combining modern pollen samples from multiple depositional environments on various pollen-based climate reconstruction methods using modern pollen sam...
Poster
Full-text available
The Early Eocene was a time of globally warm and equable climates, and is also noted for the appearance of many modern plant and insect genera, and as the time when terrestrial communities began to take on their modern form. A series of Early Eocene lake lagerstätten collectively called the Okanagan Highlands were deposited in basins from central B...
Article
Full-text available
Aim  We used modern pollen assemblages to develop a method for climate reconstruction that reduces the spatial autocorrelation of residuals and accounts for the strong topographic and climatic variation that occurs in British Columbia, Canada.Location  British Columbia, Canada, including sites both on the mainland and on adjacent islands (Queen Cha...
Article
Clague, J. J., Mathewes, R. W., Guilbault, J.-P., Hutchinson, I. & Ricketts, B. D. 1997 (September): Pre-Younger Dryas resurgence of the southwestern margin of the Cordilleran ice sheet, British Columbia, Canada. Boreas, Vol. 26, pp. 261–278. Oslo. ISSN 0300–9483. A lobe of the Cordilleran ice sheet readvanced into the central Fvaser Lowland, south...
Poster
Full-text available
The Quilchena site in the southern interior of BC is one of several Okanagan Highlands (OH) fossil floras now known to date mostly to the Ypresian (Early Eocene). Quilchena is securely dated radiometrically at 51.5 mya, which places it at the beginning of the Early Eocene warm interval. Both leaf-margin analysis of dicot leaves and bioclimatic reco...
Article
Pollen and plant macrofossil analyses of lake sediments from Anthony Island in the southern Queen Charlotte Islands (Haida Gwaii), British Columbia, reveal 1800 yr of relatively stable temperate rainforest vegetation. Cupressaceae (cedar) pollen percentages and accumulation rates decline about 1000 cal yr BP, coincident with occupation of the islan...
Article
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Moraine Bog lies just outside the outermost lateral moraine of Tiedemann Glacier in the southern Coast Mountains of British Columbia. A sediment core taken from the wetland was analyzed for pollen, magnetic susceptibility, and loss on ignition to reconstruct changes in vegetation and climate during the late Holocene. Vegetation changed little betwe...