The Paleobiota of the Klondike Mountain Formation comprises a diverse suite of Early Eocene plants and animals recovered in North Central Washington State from the Klondike Mountain Formation. The formation outcrops in locations across the north western area of Ferry County, with major sites in Republic, north west of Curlew Lake, and on the Toroda Creek area. The formation is the southern most of the Eocene Okanagan Highlands, sharing much of the paleoflora and paleofauna with site across Central and southern British Columbia.
Plants Bryophytes Dillhoff et al. (2013) reference undescribed moss specimens known from the Klondike Mountain Formation known from vegetative gametophytes and they noted them to be similar to undescribed specimens from the Allenby Formation and Horsefly shales. Family Genus Species Authors Year Notes ImagesUndescribedUndescribedUndescribedUndescribed moss specimens
Lycophytes Rare specimens of Selaginella fossils were noted by Wehr (1998), with no species level description. Family Genus Species Authors Year Notes ImagesSelaginellaceaeSelaginella UndescribedA spikemoss Not described to species
Pteridophytes Family Genus Species Authors Notes ImagesCystopteridaceaeCf. CystopterisUndescribedA possible bladder fern relative Not described to speciesDennstaedtiaceaeDennstaedtia†Dennstaedtia christopheliiPigg et al.A Hayscented fern EquisetaceaeEquisetumUndescribedA scouring rush Not described to speciesHymenophyllaceaeHymenophyllum†Hymenophyllum axsmithiiPigg et al.A filmy fernLygodiaceaeLygodiumUndescribedA climbing fern Not described to speciesSalviniaceaeAzolla†Azolla primaevaArnoldA mosquito fernSalviniaceaeSalviniaUndescribed A "watermoss" species.Not described to species Found only in Curlew half graben sites.
Gymnosperms Three major groups of gymnosperms are present in the Klondike Mountain Formation, with the most speciose being the pinophytes. The ginkgophytes are represented by two species of Ginkgo, while an undescribed Zamiaceae member is the sole cycadophyte.
Cycadophytes Family Genus Species Authors Notes ImagesZamiaceaeUndescribedUndescribedA zamiaceous cycad. Not described to genus/species
Gingkophytes Family Genus Species Authors Notes Images Ginkgoaceae GinkgoGinkgo bilobaLinnaeusA ginkgo†Ginkgo dissectaMustoeA ginkgo
Pinophytes Family Genus Species Authors Notes Images CupressaceaeCalocedrusUndescribedAn incense cedarNot described to speciesChamaecyparisUndescribedA false cypressNot described to speciesPossibly in the Callitropsis nootkatensis lineage.CryptomeriaUndescribedA sugiNot described to speciesGlyptostrobusUndescribedA Chinese swamp cypressNot described to speciesMetasequoia†Metasequoia occidentalis(Newberry) ChaneyA dawn redwoodSequoia†Sequoia affinisLesquereuxA coast redwood Reported as "Sequoia langsdorfii" by Brown, 1935TaiwaniaUndescribedA Taiwania speciesnot described to speciesTaxodium†Taxodium dubium(Sternberg) HeerA bald cypressThujaUndescribedAn arborvitaeNot described to speciesThujopsis?UndescribedA possible ThujopsisNot described to species. PinaceaeAbies†Abies milleriShorn & WehrOldest true fir describedPiceaUndescribedA spruce Not described to species Pinus†Pinus latahensisBerryA 5-needle pine†"Pinus macrophylla"BerryA 3-needle pine, jr homonym to Pinus macrophylla Lindley 1839 †Pinus monticolensisBerryA pine seed morphogenus†Pinus tetrafolia BerryA purported 4-needle pine Noted by Berry as "highly improbable that this should represent a distinct botanic species"Pseudolarix†Pseudolarix wehriiGoochA golden larch Originally described as Pseudolarix americana. TsugaUndescribedA hemlockNot described to speciesSciadopityaceaeSciadopitysUndescribedAn umbrella pine Not described to species TaxaceaeAmentotaxusUndescribedA yew Not described to speciesCephalotaxusUndescribedA yewOriginally placed in the Miocene Cephalotaxus bonseri Not described to speciesTaxusUndescribedA yewNot describedCf. TorreyaUndescribedA plum-yew relative Not described to genus/species
Flowering plants Angiosperms, commonly called flowering plants belong to a single plant clade which diverged from other plants during the prior to the Cretaceous, and began to rapidly evolve and radiate by the Middle Cretaceous. Angiosperm diversification during the Cretaceous and Paleocene resulted in eight recognized clades that are segregated into two groups the Basal angiosperms and Core angiosperms. Present in the Klondike Mountain Formation are four of the eight groups, Nymphaeales representing Basal Angiosperms, plus Magnoliids, Monocots, and Eudicots all in the Core angiosperms.
Nymphaeales The Basal Angiosperms are represented by a single Nymphaeales water-lily species Nuphar carlquistii, though a second member, Allenbya collinsonae, has been described from the Princeton Chert. Wehr (1995) illustrated two fossils that were tentatively identified as fruits of the banana genus Ensete and the extinct myrtle genus Paleomyrtinaea respectively, however further fossil finds resulted in the re-identification of the first as a N. carlquistii rhizome section, and the second is a seed mass from the same water-lily.
Family Genus Species Authors Notes ImagesNymphaeaceaeNuphar†Nuphar carlquistiiDeVore, Taylor, & PiggA waterlily, Rhizome sections were first identified as Ensete Seed masses first identified as Paleomyrtinaea.
Magnoliids Under the APG IV system of flowering plant classification, the magnoliids are divided into four orders Canellales, Laurales, Magnoliales, and Piperales. Member species and undescribed taxa placed confidently in the Laurales and Magnoliales are present in the formation. The laurales are the most diverse magnoliid order of the formation with one described species Sassafras hesperia plus three tentatively identified genera which have not been described. Of the magnoliales, only an undescribed Magnolia, having possible affinity with Magnolia subg. Talauma, is found in the formation, while Liriodendroxylon princetonensis has described from permineralized wood in the Princeton Chert. The extinct angiosperm genus Dillhoffia has noted similarities to the piperalean family Aristolochiaceae, but was left incertae sedis as to family by Manchester and Pigg (2008) due to a lack of confident morphological characters for placement. Piperales are known from the Princeton chert, with Saururus tuckerae representing the oldest confident Saururaceae species in the fossil record.
Family Genus Species Authors Notes Images Lauraceae†LitseaphyllumUndescribedA lauraceous form species. Not described to speciesOcoteaUndescribedA stinkwood species. Not described to speciesPhoebeUndescribedA Phoebe species. Not described to speciesSassafras†Sassafras hesperiaBerryA sassafrasMagnoliaceaeMagnoliaUndescribedA magnolia, possibly Magnolia subgenus Talauma Not described to speciesincertae sedis†Dillhoffia†Dillhoffia cachensisManchester & PiggA flower of uncertain floral affinity
Monocots The second largest clade of flowering plants, monocots are divided into eleven separate orders and of those, the Alismatales, Asparagales, Liliales, and Poales are found in the Klondike Mountain Formation, each represented by a single taxon. The Alismatales are represented by the Araceae species Orontium wolfei, which is considered similar to the modern golden clubs of eastern North America, while the extinct Paleoallium belongs to the Liliales. Asparagales and Poales are both present as undescribed species associated with the genera Smilax and Typha respectively. Extinct genera of monocots are also represented in the Princeton chert by the arecalean palm Uhlia, the alismatalean genus Heleophyton, the alismatalean Keratosperma, the asparagalean pollen morphogenus Pararisteapollis, the lilialean genus Soleredera, and the poalean genus Ethela,
Family Genus Species Authors Notes ImagesAmaryllidaceae†Paleoallium†Paleoallium billgenseliPigg, Bryan, & DeVoreAn onion relativeAraceaeOrontium†Orontium wolfeiBogner, Johnson, Kvaček & UpchurchA golden clubSmilacaceaeSmilaxUndescribedA greenbrier species.Not described to species.TyphaceaeTyphaUndescribedA cattail species.Not described to species.
Eudicots
Over a dozen different Rosaceae genera, both extant and extinct, have been identified in the formation providing some of the oldest reliable macrofossil records (excluding fossil pollen) for the family. Benedict et al. (2011) described first fossils for the prunoid genus Oemleria along with the oldest Prunus flowers. The Prunus flowers are complemented by leaf fossils representing five to six distinct morphotypes. Spiraea is known from an inflorescence with multiple flowers and leaves that are either from the genus or a closely related extinct type. The leaves frequently are preserved with a persistent stipule, a feature not found in modern Spiraea species. The firethorn genus Pyracantha and the South American genus Hesperomeles have been tentatively identified from leaves while Maloidea leaves belonging to either Malus or Pyrus have been found. Two distinct species of the Asian endemic genus Photinia are known, however only one of them Photinia pageae had been described as of 2007. The rosaceous genus Physocarpus had been reported by Hopkins and Wehr (1994) as also occurring in the formation, however subsequent examination of the fossils by Oh & Potter (2005) failed to find stellate trichomes which are a distinct feature of the genus. They noted the fossils might be stem Neillieae, the rose tribe containing both Physocarpus and Neillia, or possibly Rubus, Crataegus, or Ribes.
Fossils of both Sorbus and Rhus species leaves showing evidence of being interspecies hybrids have been noted from the formation and Flynn, DeVore and Pigg (2019) described four species of sumac which formed multiple hybrids. Between three and four Trochodendraceae species that have been described from the Klondike Mountain Formation. Broadly circumscribed four species in three genera have been identified at Republic, Paraconcavistylon wehrii, Pentacentron sternhartae, Tetracentron hopkinsii, and Trochodendron nastae. Additionally the species Trochodendron drachukii is known from related Kamloops group shales at the McAbee Fossil Beds near Cache Creek, British Columbia. Manchester et al. 2018 noted that Tr. drachukii is likely the fruits of Tr. nastae, while Pe. sternhartae are likely the fruits of Te. hopkinsii. If fossils of the fruits and foliage in attachment are found, that would bring the species count down to three whole plant taxa. Additionally, the extinct genus Nordenskioldia is also known from the formation. The placement of Nordenskioldia is debated, with some treatments placing it into Trochodendraceae, while a 2020 analysis placed it outside of the crown-group Trochodendaceae. Wesley Wehr in 1994 reported Bignoniaceae seeds along with a single Rubiaceae fruit and an isolated Fabaceae leaf. An update of the floral list by Wehr and Manchester published in 1996 added an additional fifteen taxa identified from reproductive structures such as flowers fruits or seeds.
Pigg, Manchester, and Wehr (2003) noted in during the description of Corylus johnsonii and Carpinus perryae that they were the oldest confirmed hazelnut and hornbeam fossils. That status was affirmed by Forest et al. (2005) who used both as fossil calibration points for phylogenetic analysis of Betulaceae. Within the family Bignoniaceae, the fossil seeds and fruits are noted by Ze-Long Nie et al (2006) as the oldest confirmed for the family.