Richard M. Dillhoff

• University of Washington

The Eocene flora of the Okanogan Highlands in the Pacific Northwest of North America has been recognized previously to include extinct species of both extant genera of the Trochodendraceae. Here, using microcomputed tomography (μCT) scanning to augment traditional methods, we recognize additional diversity, including two new fruit types. Concavisty...

A flora from Thomas Ranch near Princeton, British Columbia, Canada, is assessed for biodiversity and paleoclimate. This latest Early to early Middle Eocene flora occurs in the Allenby Formation. Seventy-six megafossil morphotypes have been recognized, representing at least 62 species, with 29 identified to genus or species. Common taxa include Gink...

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...

The John Day Basin of central Oregon contains a remarkably detailed and well-dated Early Eocene–Late Miocene sedimentary sequence, known for its superb fos-sils. This fi eld trip examines plant fossil assemblages from throughout the sequence in the context of their geological and taphonomic setting and regional and global signifi cance. The Early t...

Newly recognized fossil infructescences and leaves of the Trochodendraceae are described from the Early/ Middle Eocene McAbee and One Mile Creek sites of British Columbia, Canada, and Republic, eastern Washington State, United States. Trochodendron drachukii Pigg, Dillhoff, DeVore, & Wehr sp. nov., from McAbee, is an infructescence similar to that...

Eocene nonmarine sedimentary rocks that occur in northwest and central Washington as a widespread series of outcrops are evidence of a meandering river system that existed prior to the mid-Tertiary uplift of the North Cascade Range. Arkosic strata appear to have initially been deposited in a basin that was later divided by strike-slip faulting, pro...

Leaves and fruits of Ulmus from the Early–Middle Eocene of British Columbia and Washington are assigned to two species. Ulmus okanaganensis sp.nov. is based on leaves attached to flowering and fruiting twigs and isolated leaves and fruits. Leaves display a polymorphism ranging from large leaves with compound teeth with a blunt apex to small ones wi...

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 sepa...

This mine has produced high quality realgar specimens for over 20 years. The crystal habit ranges from stubby to nearly acicular prisms on white sandstone and black shales. Realgar, an arsenic sulphide crystallizes in the monoclinic system. Most material is massive and crystals are rare. When they do occur they are usually short prismatic, often wi...