''Uhlia'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of coryphoid palm containing a

single Single may refer to: Arts, entertainment, and media * Single (music), a song release Songs * "Single" (Natasha Bedingfield song), 2004 * "Single" (New Kids on the Block and Ne-Yo song), 2008 * "Single" (William Wei song), 2016 * "Single", by ...

species ''Uhlia allenbyensis''. The species is known from

permineralized Permineralization is a process of fossilization of bones and tissues in which mineral deposits form internal casts of organisms. Carried by water, these minerals fill the spaces within organic tissue. Because of the nature of the casts, perminera ...

remains recovered from the

Princeton Chert The Princeton Chert is a fossil locality in British Columbia, Canada, which comprises an anatomically preserved flora of Eocene Epoch age, with rich species abundance and diversity. It is located in exposures of the Allenby Formation on the east ...

in British Columbia, Canada. Leaves of ''Uhlia'' have "tar spot"-like fungal infections of the extinct

ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ...

'' Paleoserenomyces'', which in turn are hyperparasitized by the ascomycete '' Cryptodidymosphaerites''.

Distribution

''Uhlia allenbyensis'' is known exclusively from the

, a fossil locality in British Columbia, Canada, which comprises an anatomically preserved flora of Eocene Epoch age, with rich species abundance and diversity. The chert is located in exposures of the Allenby Formation on the east bank of the

Similkameen River The Similkameen River runs through southern British Columbia, Canada, eventually discharging into the Okanagan River near Oroville, Washington, in the United States. Through the Okanagan River, it drains to the Columbia River. The river is said ...

, south of the town of

Princeton, British Columbia Princeton (originally Vermilion Forks) is a town in the Similkameen region of southern British Columbia, Canada."The rich history of Princeton or how Vermilion Forks made it on the map...", Princeton 2008 Visitors Guide, p. 4. It lies just east o ...

. Notable in conjunction with the coal seams of the Allenby Formation are sections of chert which formed during silica-rich periods. The rapid cyclical changes from coal to chert and back are not noted in any other fossil locality in the world. An estimated 49 coal/chert cycles are known, though the exact conditions for this process are not well understood. Silica-rich volcanic episodes in the region during deposition would have been needed for formation of the cherts, while slowly moving waters and gently subsiding terrains would be needed for the peats and fens to accumulate. Rates of organic deposition in swamps have been estimated at approximately in modern temperate climates, this suggests the time needed for each chert layer would be at least 100 years or more, with the full sequence of cycles taking place over no more than 15,000 years. The Allenby Formation is the southernmost of the Eocene Okanagan Highlands lakes in British Columbia and second most southern site after the

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation, named for the type location designated in 1962, Klondike Mountain north of Republic, Wash ...

Republic, Washington Republic is a city in Ferry County, Washington, United States. The population was 1,073 at the 2010 census, a 12.5% increase over the 2000 census. It is the county seat of Ferry County. It was the largest mining camp in the Republic Mining Distr ...

, in northern Ferry County. In British Columbia, the formation is coeval to the Tranquille Formation, known from the McAbee Fossil Beds and

Falkland site Falkland may refer to: * Falkland, British Columbia, a community in Canada * Falkland, Nova Scotia, a community in Canada * Falkland Islands, an archipelago in the south Atlantic Ocean * Falkland, Fife, a former burgh in Fife, Scotland ** Falklan ...

, the

Coldwater Beds The Coldwater Beds are a geologic formation of the Okanagan Highlands in British Columbia, Canada. They preserve fossils dating back to the Ypresian stage of the Eocene period, or Wasatchian in the NALMA classification.Quilchena site, and Driftwood Canyon Provincial Park. The highlands, including the Allenby Formation, have been described as one of the "Great Canadian '' Lagerstätten''" 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.

History and classification

The chert palm fossils were first briefly described in 1976 by James Basinger as part of his PhD thesis; however, due to the isolated nature of the leaf and petiole specimens known at that time, the fossils were not given specific taxonomic treatment. Additional collecting and examination of recovered chert blocks over the next decade and a half included additional palm fossils and allowed for in-depth study by paleobotanists Diane Erwin and

Ruth Stockey Ruth (or its variants) may refer to: Places France * Château de Ruthie, castle in the commune of Aussurucq in the Pyrénées-Atlantiques département of France Switzerland * Ruth, a hamlet in Cologny United States * Ruth, Alabama * Ruth, Arka ...

in the early 1990's. Erwin and Stockey used cellulose acetate peels with

hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...

to create serial thin sections of the fossils for anatomical and cellular study. The microscope slides were accessioned into the University of Alberta palaeobotanical collections. The formal description of the new genus and species was published by Erwin and Stockey (1994) in the journal '' Palaeontographica Abteilung B'', with the genus name ''Uhlia'' being chosen as a

matronym A matronymic is a personal name based on the given name of one's mother, grandmother, or any female ancestor. It is the female equivalent of a patronymic. Around the world, matronymic surnames are far less common than patronymic surnames. In som ...

honoring palm systematist

Natalie Uhl Natalie Whitford Uhl (1919–2017) was an American botanistIPNI: Natalie Whitf ...

in recognition of her work on palm taxonomy and the specific name ''allenbyensis'' coined from

Allenby, British Columbia Allenby was an important copper-mining company town in the Similkameen Country of the Southern Interior of British Columbia, Canada, just south of the town of Princeton. It was for a short time the location of the Copper Mountain post office but ...

, the ghost town that the Allenby Formation takes its name from. In the type description, ''U. allenbyensis'' was assigned to the palm subfamily

Coryphoideae The Coryphoideae is one of five subfamilies in the palm family, Arecaceae. It contains all of the genera with palmate leaves, excepting ''Mauritia'', ''Mauritiella'' and ''Lepidocaryum,'' all of subfamily Calamoideae, tribe Lepidocaryeae, subtr ...

and tribe

Corypheae Corypheae is a tribe of palm trees in the subfamily Coryphoideae. In previous classifications, tribe Corypheae included four subtribes: Coryphinae, Livistoninae, Thrinacinae and Sabalinae, but recent phylogenetic studies have led to the genera ...

based on the similarity in leaf and stem anatomy to the living genera ''

Brahea ''Brahea'' is a genus of palms in the family Arecaceae. They are commonly referred to as hesper palms and are endemic to Mexico and Central America.Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of t ...

'', ''

Rhapidophyllum ''Rhapidophyllum hystrix'', the needle palm, is a palm, the sole member of the genus ''Rhapidophyllum''. It is native to coastal margins of the subtropical eastern Gulf and south Atlantic states of the United States. Endemic populations can be f ...

'', and '' Serenoa''. Subsequently phylogenetic evaluation of Coryphoideae has led to tribe Corypheae being restricted to only the type genus, with all other former members being placed on other tribes,

Cryosophileae Cryosophileae is a tribe of palms in the subfamily Coryphoideae. The tribe ranges from southern South America, through Central America, into Mexico and the Caribbean. It includes New World genera formerly included in the tribe Thrinacinae, wh ...

or Trachycarpeae.

Description

''Uhlia allenbyensis'' was a rhizomatous palm, with roots growing from the lower side of stems and leaves from the upper side. The roots range between wide with a central

stele A stele ( ),Anglicized plural steles ( ); Greek plural stelai ( ), from Greek , ''stēlē''. The Greek plural is written , ''stēlai'', but this is only rarely encountered in English. or occasionally stela (plural ''stelas'' or ''stelæ''), whe ...

. The root cortex displays a narrow innermost layer of cells, and a middle cortex with a aerenchymous structure. The stems show a periderm-like layer of cells having irregular to rectangular shape and organized into vertical rows. Underlying the periderm-like layer the stem tissues are grouped into three major zones. The innermost zone, the central region, extends from the stem center to the boundary point with the "B zone". The peripheral area of the central region displays both leaf traces and vascular groupings which were interpreted as inflorescence traces.

Paleobiology

Leaves of ''Uhlia allenbyensis'' show parasitism by the parasitic fungus '' Paleoserenomyces allenbyensis'' which invaded the leaf surface cells. These parasitized areas have been described as similar to modern "

tar spot ''Rhytisma acerinum'' is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot. Tar spot does not usually have an adverse effect on the trees' long-term health. ''R. acerinum'' is an Ascomycete f ...

" infections on leaves. In some cells of ''P. allenbyensis'' the hyperparasitic fungus ''

Cryptodidymosphaerites princetonensis ''Cryptodidymosphaerites'' is an extinct monotypic genus of pleosporale fungus of uncertain family placement. When described it contained the single species ''Cryptodidymosphaerites princetonensis''. The genus is solely known from the Early Eoc ...

'' was preserved, providing a firm fossil record for fungal hyperparasitism. The low stature of ''U. allenbyensis'' has been likened to that of the modern saw palmetto '' Serenoa repens'', a morphology consistent with its tribal placement. Palm beetle fossils are also found in the greater Okanagan highlands, both in the Tranquille Formation north of Princeton and in the

to the south. The beetles have been assigned to the '' Caryobruchus'' – '' Speciomerus'' genus group and are obligate parasites of palms in the tribes Cocoaceae, Coryphaea, Hyphorbeae, and

Phoeniceae ''Phoenix'' is a genus of 14 species of palms, native to an area starting from the Canary Islands in the west, across northern and central Africa, to the extreme southeast of Europe (Crete), and continuing throughout southern Asia from Turkey e ...

Paleoenvironment

The Princeton chert preserves an aquatic system with silica rich slow moving waters which was likely a peat fen ecosystem. While other fossil producing areas of the Allenby Formation are likely the product of deep water deposition and diatomite sedimentation, the chert layers originate from shallow waters, as evidenced by plant and animal fossils. The Okanagan Highland sites, such as the Princeton chert represent upland lake systems that were surrounded by a warm temperate ecosystem with nearby volcanism. The highlands likely had a

mesic Mesic may refer to: * Mesic, North Carolina, a town in the United States * Mesic habitat, a type of habitat See also *Mesić (disambiguation) *Mešić Mešić is a Bosnian surname, a patronymic derived from the masculine given name '' Meša'', it ...

upper microthermal to lower mesothermal climate, in which winter temperatures rarely dropped low enough for snow and which were seasonably equitable. The Okanagan Highlands paleoforest surrounding the lakes have been described as precursors to the modern temperate broadleaf and mixed forests of Eastern North America and Eastern Asia. Based on the fossil

biota Biota may refer to: * Biota (ecology), the plant and animal life of a region * Biota (plant), common name for a coniferous tree, ''Platycladus orientalis'' * Biota, Cinco Villas, a municipality in Aragon, Spain * Biota (band), a band from Color ...

s, the lakes were higher and cooler than the coeval coastal forests preserved in the

Puget Group The Puget Group is a geologic group in Washington (state). It preserves fossils dating back to the Paleogene period. Two key formations include the Renton Formation and the Tukwila Formation. See also * List of fossiliferous stratigraphic ...

and

Chuckanut Formation The Chuckanut Formation in northwestern Washington (named after the Chuckanut Mountains, near Bellingham, Washington, Bellingham), its extension in southwestern British Columbia (the Huntingdon Formation), and various related Geological formati ...

of Western Washington, which are described as lowland tropical forest ecosystems. Estimates of the paleoelevation range between higher than the coastal forests. This is consistent with the paleoelevation estimates for the lake systems, which range between , which is similar to the modern elevation of but higher. Estimates of the mean annual temperature have been derived from climate leaf analysis multivariate program (CLAMP) analysis and leaf margin analysis (LMA) of the Princeton paleoflora. The CLAMP results after multiple linear regressions for Princeton's gave a , and the LMA returned a mean annual temperature of . This is lower than the mean annual temperature estimates given for the coastal Puget Group, which is estimated to have been between . The bioclimatic analysis for Princeton suggest mean annual precipitation amount of . The warm temperate uplands floras of the Allenby Formation and greater highlands in association with downfaulted

lacustrine basin A lacustrine plain or lake plain is a plain formed due to the past existence of a lake and its accompanying sediment accumulation. Lacustrine plains can be formed through one of three major mechanisms: glacial drainage, differential uplift, and inla ...

s and active volcanism are noted to have no exact modern equivalents. This is due to the more seasonally equitable conditions of the Early Eocene, resulting in much lower seasonal temperature shifts. However, the highlands have been compared to the upland ecological islands in the Virunga Mountains within the Albertine Rift of the

African rift valley The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of ...

References

{{Taxonbar, from=Q113318882

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species). It is one of the modern descendan ...

Eocene life of North America Prehistoric angiosperm genera Allenby Formation Fossil taxa described in 1994 Monotypic Arecaceae genera