''Orontium wolfei'' is an extinct golden-club

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in the family

Araceae The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). A ...

described from a series of isolated

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

leaves. The species is known from

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

sediments exposed in the state of

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

in the

United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

and the province of

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

in Canada. It is one of several extinct species placed in the living golden-club genus ''

Orontium ''Orontium'' , sometimes called golden-club, is a genus of flowering plants in the family Araceae. The single living species in the genus is '' Orontium aquaticum'', while the two other described species, '' Orontium mackii'' and '' Orontium wolf ...

''.

History and classification

''Orontium wolfei'' has been identified from a group of exposures of the

Allenby Formation The Allenby formation is a sedimentary rock formation in British Columbia which was deposited during the Ypresian stage of the Early Eocene. It consists of conglomerates, sandstones with interbedded shales and coal. The shales contain an abunda ...

and a group of exposures of the related Klondike Mountain Formation. The type locality is at the "One mile Creek" exposure of the Allenby Formation near

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 ...

and additional fossils have been recovered from the Lamont Creek site near Princeton. The Allenby Formation is currently considered to be Early Eocene in age, based on Potassium–argon

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...

plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more pro ...

and biotite crystals. The second group of fossils have been recovered from three outcrops of the early to early Middle Eocene Klondike Mountain Formation around Republic, Washington. Fossils in the Klondike Mountain Formation are found in mudstone and shale layers of the lower part of the formation. The lakes which produced these fossils are estimated to have been active between 48 and 49 million years ago, with the lava flows in the formation dating between 42 and 50 million years old. Fossils of ''O. wolfei'' found in the Klondike Mountain Formation have been noted, prior to the species description, as belonging to the extinct morphogenus '' Zingiberopsis'' in collections and publications. ''Zingiberopsis'' is a form taxon for

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', th ...

to Oligocene fossil leaves found in Western North America which are related to the modern

Zingiberales The Zingiberales are flowering plants forming one of four orders in the commelinids clade of monocots, together with its sister order, Commelinales. The order includes 68 genera and 2,600 species. Zingiberales are a unique though morphologi ...

, a plant order which includes modern bananas and gingers.The Angiosperm Phylogeny Website
/ref> This identification was made by Jack A. Wolfe for specimens in the paleobotanical collection of the

Burke Museum The Burke Museum of Natural History and Culture (Burke Museum) is a natural history museum in Seattle, Washington, in the United States. Established in 1899 as the Washington State Museum, it traces its origins to a high school naturalist club fo ...

Seattle, Washington Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region ...

. The species was described from a

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

, the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

specimen DMNH-26516 which is currently preserved in the paleobotanical collections housed at the

Denver Museum of Nature and Science The Denver Museum of Nature & Science is a municipal natural history and science museum in Denver, Colorado. It is a resource for informal science education in the Rocky Mountain region. A variety of exhibitions, programs, and activities help mus ...

, in

Denver, Colorado Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...

. The specimens were studied by a group of

paleobotanist Paleobotany, which is also spelled as palaeobotany, is the branch of botany dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments (paleogeogr ...

s led by Josef Bogner, with the team publishing their 2007 type description for ''O. wolfei'' in the Journal ''Zitteliana''. The

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

of the chosen specific name ''wolfei'' is in recognition of paleobotanist Jack Wolfe for his work on the Western North American Paleogene.

Description

The leaves of ''O. wolfei'' are an elongated elliptical shape overall, being between and over long. The leaves range from in width, with the full length of large leaves and the structure of the leaf petiole unknown as complete specimens have not been found. The leaf tips are hooded in shape and the veins are a sub-parallel showing a very indistinct midrib. The primary veins and major secondary veins start near the leaf base and are connected by a dense tertiary and higher order veins forming a mesh of elongated aerolae. The pattern of the veins is characteristic of the family Araceae and confirms this species' placement in it.

References

{{Taxonbar, from=Q7103804 Orontioideae Prehistoric angiosperms Plants described in 2007 Fossil taxa described in 2007 Ypresian plants of North America Flora of Washington (state) Flora of British Columbia Extinct flora of North America Klondike Mountain Formation Allenby Formation