''Acer cascadense'' is an extinct

maple ''Acer'' is a genus of trees and shrubs commonly known as maples. The genus is placed in the soapberry family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated si ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in the family

Sapindaceae The Sapindaceae are a family (biology), family of flowering plants in the order Sapindales known as the soapberry family. It contains 138 genera and 1,858 accepted species. Examples include Aesculus, horse chestnut, maples, ackee and lychee. The ...

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 preserve ...

samaras Samaras (; feminine: Samara) is a Greek surname meaning 'saddler'. Notable people with the surname include: * Antonis Samaras (born 1951), Greek politician; Prime Minister of Greece, 2012–15 * Georgios Samaras (born 1985), Greek footballer * I ...

. The species is known from

s found in

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

deposits of central

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

. It is one of several extinct species placed in the living '' Acer'' section '' Negundo''.

Distribution and paleoenvironment

''Acer cascadense'' fossils were found in the Moose Mountain Flora, formerly called the Cascadia flora or Menagerie Wilderness flora, of

Linn County, Oregon Linn County is one of the Oregon counties, 36 counties in the U.S. state of Oregon. As of the 2020 United States census, 2023 census population estimates, the population was 131,496. The county seat is Albany, Oregon, Albany. The county Oreg ...

. The flora is included in the Little Butte Volcanic series outcropping near the town of Cascadia in the central Oregon Cascades. Work on the flora by paleobotanist Jack Wolfe in 1964 gave an estimated age of Early Miocene, this was later revised by Wolfe and Tanai in 1987 to a Late Oligocene estimation. In the descriptive paper naming ''T. postnastae'' Manchester ''et al'' reported that radioisotope dating of

plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...

crystals collected by Robert Rosé from the fossiliferous horizon of the Moose Mountain flora had been performed. Using crystals obtained from tuffaceous sandstones,

Argon–argon dating Argon–argon (or 40Ar/39Ar) dating is a radiometric dating method invented to supersede Potassium-argon dating, potassiumargon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measur ...

provided an age of 14.91 ± 0.23 Ma placing the flora as Middle Miocene

Langhian The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene Epoch/Series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma (million years ago) during the Middle Miocene.GeoWhen (2007) The Langhian was ...

stage. ''Acer cascadense'' is found associated with extinct species including '' A. smileyi'', '' Concavistylon kvacekii'', '' Ozakia emryi'', ''

Trochodendron postnastae ''Trochodendron postnastae'' is an extinct species of flowering plant in the family Trochodendraceae. The species is known from fossils found in Middle Miocene deposits of central Oregon. ''T. postnastae'' are possibly the leaves belonging to t ...

'', and '' Trochodendron rosayi''.

Taxonomy

The species

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

was originally collected during the 1950's by Eleanor Gordon Thompson and donated to the

University of California Museum of Paleontology The University of California Museum of Paleontology (UCMP) is a paleontology museum located on the campus of the University of California, Berkeley. The museum is within the Valley Life Sciences Building (VLSB), designed by George W. Kelham ...

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Anglo-Irish bishop and philosopher George Berkeley. It borders the cities of Oakland, Cali ...

as specimen UCMP 9055. Several additional helicopter fossils were identified in the

National Museum of Natural History The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 ...

paleobotany collections, and described as

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

s. The specimens were studied by

paleobotanist Paleobotany or palaeobotany, also known as paleophytology, is the branch of botany dealing with the recovery and identification of plant fossils from geological contexts, and their use for the biological reconstruction of past environments (pale ...

Jack A. Wolfe Jack Albert Wolfe (1936–2005) was a United States Geological Survey paleobotanist and paleoclimatologist best known for his studies of Tertiary climate in western North America through analysis of fossil angiosperm leaves A leaf (: l ...

of the United States Geological Survey, Denver office and Toshimasa Tanai of

Hokkaido University , or , is a public research university in Sapporo, Hokkaido, Japan. Founded in 1918, it is the fifth-oldest government-authorised university in Japan and one of the former Imperial Universities. The university finds its roots in Sapporo A ...

. Wolfe and Tanai published their 1987

type description A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

for ''A. cascadense'' in the ''Journal of the Faculty of Science, Hokkaido University''. The

etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

of the chosen

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''cascadense'' is in reference to the type locality, known at the time as the Cascadia flora, which is in the Northern Oregon

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the ...

Description

''A. cascadense'' samaras have a elliptical long nutlet that is moderately inflated. The base of the fruit has a attachment scar and a 35° to 50° attachment angle for the opposite fruit in the samara pair. A series of up to six veins arise from the attachment scar and run parallel across the nutlet towards the contact between wing and nutlet. The overall length of the samara wing is between with a maximum width of . The lower edge of the wing is a smooth convex curve angling out from the basal sulcus up to the narrow rounded wing tip, while the upper edge of the wing is straight from nutlet to wing tip. Four to five veins branch from the proximal edge of the wing at 10° to 30° angles and from convex arcs along the wing, forking and frequently anastomising.

References

{{Taxonbar, from=Q104708998 †cascadense Prehistoric angiosperms Plants described in 1987 Fossil taxa described in 1987 Miocene plants Extinct flora of North America Fossils of the United States