The species is dated to the Early Eocene Ypresian stage and has only been found at the type locality in east central British Columbia.

[3] Fossil material was studied subsequently by Alexander Wolfe and Mark Edlund (2005) with the type description of the species being published in the Canadian Journal of Earth Sciences.

Wolfe and Edlund coined the specific epithet wilsonii as a patronym honoring Mark Wilson as recognition for his enormous work on western North American Eocene lake paleolimnology and paleoichthyology.

Unlike Aulacoseira giraffensis from the similarly aged Giraffe maar kimberlite pipe deposit in the North West Territories however, the undescribed Horsefly Aulacoseira species was a minor component of the lake flora, with E. wilsonii being the dominatant bloom florming species.

[8] Additionally the extant synurid "algae" species Mallomonas intermedia has also been recovered from Horsefly,[7] while study of diatomitic sediments by George Mustoe (2005) from the McAbee Fossil Beds show undescribed Aulacoseiraceae diatoms and chrysophyte stomatocysts.

[9] The greater Eocene Okanagan Highlands likely had a mesic upper microthermal to lower mesothermal climate, in which winter temperatures rarely dropped low enough for snow, and which were seasonably equitable.

[10] The Okanagan Highlands fossil sites, which includes the Eocene formations between the Driftwood Shales near Smithers, British Columbia in the north and the Klondike Mountain Formation surrounding Republic, Washington to the south have been described collectively as one of the "Great Canadian Lagerstätten"[11] based on the diversity, quality and unique nature of the biotas that are preserved.

The highlands temperate biome preserved across such a large transect of lakes recorded many of the earliest appearances of modern genera, while also documenting the last stands of ancient lines.

[11] The warm temperate highland floras in association with downfaulted lacustrine basins and active volcanism are noted to have no exact modern equivalents.