Paleofauna of the Eocene Okanagan Highlands

[4] However the certainty for the placement was questioned earlier by Eberle et al. (2017)[5] and Archibald and Cannings (2022) who opted to tentatively exclude Quesnel from the highlands while discussing the history of field colleting in the region.

[2] The Okanagan highlands represent a snapshot of lake, wetlands, and montane forest animal life which existed approximately 15 million years ago after the Cretaceous–Paleogene extinction event.

[7] Archibald and Makarkin (2006) suggested the disjunct distribution of genera between the Danish western Limfjord coasts Fur Formation and the Okanagan highlands may have been enabled by rising crust elevations in the northern Atlantic region and subsequent increase in landmass during the Late Paleocene which linked Northern Europe with Greenland until at least the Early Eocene.

[8] The Hat Creek Amber deposits in the central region provide evidence for small and microbiotic elements of the Okanagan Highlands forests though entombed organisms such at terrestrial nematodes and microwasps that otherwise would likely not be preserved in the lake environments.

[9] The highlands as a whole have been described as one of the "Great Canadian Lagerstätten"[6] based on the diversity, quality and unique nature of the biotas that are preserved.

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

[6] David Grimaldi et al. (2018) during discussion of inclusions in Alaskan Chickaloon amber, noted the Okanagan Highlands record of latitudinal extinctions, specifically the modern southern hemisphere endemic groups Eomeropidae mecopterans and Myrmeciinae bulldog ants.

[13] The Agathis origin for Canadian Mesozoic amber was later called into question by Ryan McKellar and Alexander Wolfe (2010) based on a lack of any araucarian macrofossil history in the northern hemisphere[12] the McAbee fossils having been already reidentifed as from the cupressaceous Cunninghamia.

[21] Unspecified spider compression fossils were mentioned as occurring in passing by David Greenwood et al. (2005) while discussing the increasing taxonomic richness of the highlands, but without specific site information.

In a short Washington Geology article they reported the first identified occurrence of feathers from the Klondike Mountain Formation and crayfish from both there and the McAbee site.

[25] Subsequently an additional series of over ten fossils were recovered from McAbee and described in 2011 as Aenigmastacus crandalli by Feldmann, Carrie Schweitzer, and John Leahy.

Hat Creek amber has provided one fully described beetle species Prionocerites tattriei,[30] which is known from a larval stage specimen first reported by Poinar et al.

He noted the fossils to be some of the oldest Eocene demapterans in North America at that time and figured one undescribed specimen consisting of a females abdomen section and cerci.

[40] The modern diversity of the family is greatest in lower latitudes, and Plecia only reaches northward to the warm temperate areas of southeastern North America.

[22] In the initial description of Hat Creek Amber, Poinar et al. make note of dipteran inclusions found in the deposit but did not give any specific taxonomic identification of taxa or illustrate any specimen.

Harrington Molesworth Anthony Rice (1959) reviewed the British Columbian bibionids, notably deeming the majority of species as belonging to Plecia or an undescribed extinct genus and not Penthetria.

[29] The next year Lewis and Wehr (1993) gave a slightly more detailed description of the specimens again identifying one to Heptageniidae, possibly in the genera Heptagenia or Stenonema.

[52] Heptageniidae Indeterminate Indeterminate[52][20] A flat headed mayflynot identifiable to genus Neoephemeridae Neoephemera †Neoephemera antiqua[52] A squaregill mayfly Greenwood et al. (2005) briefly discussed the prevalence of Aphid fossils at highlands sites where the taphonomic factors allowed for fine detail preservation such as in the Driftwood shales.

If the distortion was lateral, then compression to bilateral symmetry yielded an adult length of approximately 3.3 cm (1.3 in), placing it the same range as Formicium berryi and F. brodiei, known only from wings, and suggested as possible males.

Conversely stretching the fossil to bilateral symmetry results in a larger 5 cm (2.0 in) length estimate, placing it as comparable to queens of T. lubei and T.

This was later questioned by Conrad Labandeira who noted the scar patterns did not match modern Altica egg laying behaviour.

The next descriptive work for a fish came in 1916 with the naming of "Lucious" rosei by Louis Hussakof from Tranquille Formation fossils collected at "Red point" on Kamloops Lake in 1914.

[100] "Lucious" rosei was redescribed in 1966 by Ted Cavander, who moved the species to a new genus Eohiodon placed into the mooneye family Hiodontidae.

[110] In his 1995 Masters thesis, G. Guthrie listed an isolated tooth from the Quilchena site as from a crocodile, which would have been the only instance of a crocodylian in the highlands.

[28] The taxonomic affinity was later revised after further examination and Mathewes et al. (2016) listed the specimen as an unidentified fish tooth.

[113] Gerald Mayr et al. (2019) published an initial overview of the fossils with descriptions and commentary of the material, noting the taxa identified were all previously unknown to Northwestern North American Eocene sites.

[114][5] The record of Brontotheriidae is uncertain due to the split opinion regarding inclusion of the Quesnel area sediments as part of the Highlands.

[113] If the Quesnel sites are included as part of the Greater Okanagan Highlands per Archibald et al. (2018) the fauna of the region is expanded by a number of insect taxa, an additional arachnid, and a brontothere.

First described as "Aranea" columbiae (1878)[117] Nitidulidae Prometopia †Prometopia depilis[118] A sap beetle Anthomyiidae Anthomyia †Anthomyia burgessi[118][49] An anthomyiid fly.

Dolichoderus †Dolichoderus obliteratus[121] A dolichoderine ant First described as "Hypoclinea" obliterata[118] Formica †Formica arcana[118] A formicine ant Ichneumonidae Pimpla †Pimpla decessa[118] A pimpline ichneumon parasitic wasp †Pimpla saxea[118] A pimpline ichneumon parasitic wasp †Pimpla senecta[118] A pimpline ichneumon parasitic wasp Hemerobiidae †Bothromicromus †Bothromicromus lachlani[117] A hemerobiid lacewing of uncertain subfamily placement Brontotheriidae indeterminate indeterminate[122] A Brontotheriina subtribe BrontothereNot identifiable to genus Known from isolated teeth