The highlands, including the Allenby Formation, have been described as one of the "Great Canadian Lagerstätten"[4] 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.

[4] The warm temperate uplands floras of the Allenby Formation and the highlands, associated with downfaulted lacustrine basins and active volcanism are noted to have no exact modern equivalents, due to the more seasonally equitable conditions of the Early Eocene.

While reporting on additional plant fossils collected from British Columbia, Penhallow (1906) noted the likely coeval status of the Princeton basins with many of the sites now considered the Okanagan Highlands.

Coeval volcanic eruptive events are recorded as interbeds of tephras and lavas, while the riverine course is marked with depositional areas of conglomerates and sandstones.

[2] Several pteridophyte families and genera are represented as spore fossils alone, without corresponding megafossil records, including Lycopodiaceae, Osmundaceae, and Schizaeaceae.

While being the minority component of the Thomas Ranch flora by total fossil numbers, angiosperms have a higher diversity, with 45 distinct morphotypes represented as foliage, reproductive structures, or both.

[12][8] The following fossil conifers, pteridophytes, ginkgophytes and bryophytes have been described from the Allenby Formation: Amblystegiaceae Hypnites †Hypnites jovet-astiae[11][13] (Kuc) Miller An amblystegiaceous mossFirst described as Palaeohypnum jovet-asti, moved to Hypnites jovet-astiae in 1980 Amblystegiaceae Hypnites †Hypnites steerei[11][13] (Kuc) Miller An amblystegiaceous mossFirst described as Palaeohypnum steerei, moved to Hypnites steerei in 1980 Bartramiaceae †Plagiopodopsis †Plagiopodopsis eocenicus[10][13] (Kuc) Miller A bartramiaceous mossFirst described as Muscites eocenicus, moved to Plagiopodopsis eocenicus in 1980 ?Ditrichaceae †Ditrichites †Ditrichites fylesi[11] Kuc A Ditrichaceous moss incertae sedis †Muscites †Muscites maycocki[11] Kuc A moss of uncertain placement incertae sedis †Muscites †Muscites ritchiei[11] Kuc A moss of uncertain placement Equisetaceae Equisetum †Equisetum similkamense[12] Dawson A scouring rush Salviniaceae Azolla †Azolla primaeva[8] (Penhallow) Arnold A mosquito fernFirst described as Azollophyllum primaevum Ginkgoaceae Ginkgo Ginkgo biloba[14][2] Linnaeus A ginkgo Ginkgoaceae Ginkgo †Ginkgo dissecta[14][2] Mustoe, 2002 A ginkgo with highly dissected leaves Cupressaceae Chamaecyparis †Chamaecyparis linguaefolia[15] (Lesquereux) MacGinitie A false cypress Cupressaceae Metasequoia †Metasequoia occidentalis[16][2] (Newberry) Chaney A dawn redwood First identified as "Sequoia" brevifolia, "S." heeri.

"S." langsdorfii (in part), "S." nordenskiöldi, & Taxodium distichum miocenum (in part) Cupressaceae Sequoia †Sequoia affinis[15] Lesquereux A redwood Cupressaceae Taxodium †Taxodium dubium[16] (Sternberg) Heer A bald cypress First identified as "Sequoia" angustifolia, "S." langsdorfii (in part), & Taxodium distichum miocenum (in part) Pinaceae Abies †Abies milleri[2] Shorn & Wehr, 1986 Oldest true fir described Pinaceae Picea Undescribed[15] Miller A spruceNot described to species Pinaceae Pinus †Pinus latahensis[15] Berry A 5-needle pine Pinaceae Pinus †Pinus monticolensis[15] Berry A pinaceous winged seed Pinaceae Pinus †Pinus trunculus[15] Dawson, 1890 A 3-needle pine Pinaceae Pinus †Pinus tulameenensis[15] Penhallow A 5-needle pine Pinaceae Pseudolarix Pseudolarix amabilis[17] (J.Nelson) Rehder A golden larch Originally identified as Pseudolarix americana,[15] then as Pseudolarix arnoldii[18] Pinaceae Pseudolarix †Pseudolarix wehrii[17] Gooch A golden larch Anacardiaceae Rhus †Rhus malloryi[19] Wolfe & Wehr A sumac Amaryllidaceae †Paleoallium †Paleoallium billgenseli[20] Pigg, Bryan, & DeVore An onion relative Araceae Orontium †Orontium wolfei[21] Bogner, Johnson, Kvaček & Upchurch A golden-club Betulaceae Alnus †Alnus parvifolia[19][2] (Berry) Wolfe & Wehr An Alder Betulaceae Betula †Betula leopoldae[19][2] Wolfe & Wehr A birch Betulaceae †Palaeocarpinus †Palaeocarpinus stonebergae[22] Pigg, Manchester, & Wehr A coryloid genus Cercidiphyllaceae Cercidiphyllum †Cercidiphyllum obtritum[19] (Dawson) Wolfe & Wehr A katsura Fagaceae †Fagopsis †Fagopsis undulata[19] (Knowlton) Wolfe & Wehr A beech Fagaceae Fagus Undescribed[2] Grossulariaceae Ribes Undescribed[2] A gooseberry speciesNot described Hamamelidaceae Fothergilla †Fothergilla malloryi[2] Radtke, Pigg & Wehr A winter-hazel species Juglandaceae Pterocarya Undescribed[23] A wingnutNot described to species Lauraceae Lindera Undescribed[23] A laural speciesNot described to species Lauraceae Sassafras †Sassafras hesperia[19][2] Berry A laural species Malvaceae Florissantia Undescribed[24] An extinct sterculioid flowerNot described to species Myricaceae Comptonia †Comptonia columbiana[12][2] Dawson A sweet fern Nyssaceae †Tsukada †Tsukada davidiifolia[19][2] Wolfe & Wehr A dove-tree relative Platanaceae Macginicarpa Undescribed[2] Manchester A sycamore morphospecies Platanaceae †Macginitiea †Macginitiea gracilis[19] (Lesquereux) Wolfe & Wehr A sycamore Rosaceae Amelanchier Unidentified[25] A service berry Not described Rosaceae Neviusia †Neviusia dunthornei[26] DeVore, Moore, Pigg, & Wehr A snow wreath Rosaceae †Stonebergia †Stonebergia columbiana[27] Wolfe & Wehr A Sorbarieae genus Sapindaceae Acer †Acer princetonense[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer rousei[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer stockeyae[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer stewarti[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer stonebergae[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer toradense[28] Wolfe & Tanai A maple Sapindaceae Acer †Acer wehri[28] Wolfe & Tanai A maple Sapindaceae Dipteronia †Dipteronia brownii[2] McClain and Manchester A Dipteronia species Trochodendraceae Tetracentron †Tetracentron hopkinsii[29] Pigg et al. A Tetracentron relative Trochodendraceae Zizyphoides Undescribed[2] A trochodendraceous speciesNot described Ulmus Ulmus †Ulmus okanaganensis[30] Denk & Dillhoff An elm Urticaceae Cf.

Urticeae Undescribed[5] A nettle not described to genusFirst identified as Rubus[2] Incertae sedis †Chaneya †Chaneya tenuis[31] (Lesquereux) Wang & Manchester A sapindalean flower of uncertain affiliations Hydrobiidae †Micropyrgus †Micropyrgus camselli[32] L.S.

Due to complications arising from preservational distortion during diagenesis, they were unable to determine the correct size of the queen in life.

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 sugg4ested 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.

Ichneumonidae Xorides †Xorides lambei[37] (Handlirsch, 1910) A xoridine ichneumon parasitic wasp First named Xylonomus lambei (1910)[37] Tenthredinidae Eriocampa †Eriocampa tulameenensis[42] Rice, 1968 A tenthredinid sawfly †Dinopanorpidae †Dinokanaga †Dinokanaga wilsoni[43] Archibald, 2005 A dinopanorpid scorpion fly Eomeropidae †Eomerope †Eomerope simpkinsae[44] Archibald & Rasnitsyn, 2018 An eomeropid scorpionfly Ithonidae †Ricaniella †Ricaniella antiquata[45] (Scudder, 1895) A Polystoechotid-group giant lacewing[46] First described as Ricania antiquata (1895),[40] moved to Ricaniella antiquata (1897) Aeshnidae Indeterminate Indeterminate[47] A daner dragonflyWing too incomplete to determine genus affiliation.

Not to be confused with the Princeton Chert waterlily Allenbya Raphidiidae †Megaraphidia †Megaraphidia hopkinsi[48] Archibald & Makarkin, 2021 A Raphidiid snakefly Amiidae Cf.

Iridaceae †Pararisteapollis †Pararisteapollis stockeyi[86] Zetter & Hesse A possible iridaceous pollen morphotype Incertae sedis †Eorhiza †Eorhiza arnoldii[87] Robison & Person A semi-aquatic dicot of uncertain affinity.