Cercopoidea organized online dating
5) and membrane hairs on the wings of tiny fungus gnats (Fig. These fossils reveal communities in their environmental contexts some fifteen million years after the end-Cretaceous mass extinction event, affording an unprecedented opportunity to examine the origin and development of large-scale patterns of diversity, biogeography, evolution and climate. A single piece of shale (about 25 by 20 cm) from Mc Abee, BC, bearing seven orders and at least ten new species of insects (including insects not illustrated here) as well as bird and plant remains: A. We thank David Rudkin and Graham Young for their efforts in organizing both the Lagerstätten symposium at Geo Canada 2010 in Calgary, Alberta, and this series, and further thank them, Mark Wilson, and Mike Wilson for their helpful comments on this manuscript. B., 2010, A revision of the scorpionfly family Holcorpidae (Mecoptera), with description of a new species from Early Eocene Mc Abee, British Columbia, Canada: Annales de la Société Entomologique de France, v. Archibald and Makarkin (2006) also suggest that biofilm coating may have lessened taphonomic sorting of insect assemblages by surface area/mass during flotation on the lake surface, thereby increasing fidelity of the fossil assemblages to the original community compositions. This was later supported by teeth of the tillodont mammal Trogosus found in the Allenby Formation near Princeton (Russell 1935), then confirmed by K–Ar dating, which indicated Middle Eocene ages throughout the region (Rouse and Mathews 1961). S., 2006, Bulldog Ants of the Eocene Okanagan Highlands, and the history of the subfamily (Hymenoptera: Formicidae: Myrmeciinae): Annals of the Entomological Society of America, v. Scanning electron photomicrographs of fossil Ginkgo adiantoides cuticle from Falkland. 2-6) may be related, at least in part, to their entrapment in diatom blooms and subsequent coating by biofilms, as inferred for Eocene lacustrine-shale Lagerstätten elsewhere (Harding and Chant 2000; Mustoe 2005). Dawson (1891) provisionally agreed, but suggested that they might also be Eocene. Megafossils are commonly spectacularly well preserved as compressions featuring colour patterns on insects’ wings, exquisite whole flowers of Florissantia, and delicate ferns like the floating Azolla (Fig.
La série de dépôts lacustres de schiste et de charbon du début de l’Éocène des hautes terres d’Okanagan, aux con fins de l’ouest de l’Amérique du Nord, constituent un groupe important de sites fossiles particulièrement bien con servés de suites d’organismes diverses (Lagerstätten). Famous examples include the Eocene sites at Florissant, Colorado (Meyer 2003) and Messel, Germany (Schaal and Ziegler 1992), and the Cambrian Burgess Shale of British Columbia (Gould 1989). Also, there are several poorly pre served small insects, conifer needles, and other fossils not indicated here. A series of Early Eocene sites collectively called the Okanagan Highlands also fits this description well. Adiantum fern pinna (close-up of portion of I); note the preservation of sori (arrow); I. For example, taxa that are characteristic of the eastern hardwood forests of North America today and also represented in the Okanagan Highlands flora include elm (Ulmus, Fig. 3F), as well as more rare occurrences of Dipteronia, Eucommia (Fig. We also acknowledge the generous assistance of Catherine Brown and Karl Volkman of the Stonerose Interpretive Center in Republic, WA. G., 2005, Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: Climates and ecosystems across an Eocene landscape: Canadian Journal of Earth Sciences, v.
In the Early Eocene, the world experienced the highest temperatures of the Cenozoic, notably during hyperthermal events, when atmospheric carbon dioxide greatly exceeded modern levels (Zachos et al. The Okanagan Highlands forests show similarities to those of modern eastern USA, but also include many taxa that today occur in East Asia and the Pacific Northwest, alongside some that are now extinct, helping elucidate the origins and history of lineages characteristic today of microthermal broad-leaved deciduous and coniferous forests (Wolfe 1987; Manchester 1999). We wish to acknowledge Richard Hebda of the Royal BC Museum for permission to collect at the BC sites, and John Howard and Scott Mc Millan of BC Parks for facilitating work at Driftwood Canyon Provincial Park (under BC Parks permit). samara; note preservation of narrow wing (arrow); M. samara; note preservation of peripheral hairs (arrow); N. Mixed with these modern elements were such extinct taxa as the ubiquitous and often beautifully preserved Florissantia (Fig. 5) has provided the opportunity to estimate p CO The Eocene was also a time of seasonally equable temperatures, with mild winters extending into high latitudes, unlike today when such low seasonality is most associated with low latitudes (Greenwood and Wing 1995; Zachos et al. Here, forests contained palms (Uhlia) and cycads, at some localities mixed with taxa such as spruce (Erwin and Stockey 1991; Greenwood et al. Not only were these communities notable for their tropical–temperate mixture of organisms, but they possessed differing patterns of species richness than we would expect in modern temperate, mid-latitude forests. Perhaps oddly, this tropical level of diversity seen in insects and plants is not reflected in fish. These fossils were deposited at a key moment in the emergence of modern terrestrial lineages and communities before the onset of our current icehouse world climate, an ancient world with a mixture of familiar and strange life forms and environments.