''Acer chaneyi'' is an extinct

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

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

Sapindaceae The Sapindaceae are a family of flowering plants in the order Sapindales known as the soapberry family. It contains 138 genera and 1858 accepted species. Examples include horse chestnut, maples, ackee and lychee. The Sapindaceae occur in tempera ...

described from a number of

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 A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

and samaras. The species is known from

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

sediments exposed in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

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and

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in the U.S. It is one of several extinct species belonging to the living

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'' Rubra''.

Taxonomy

''Acer chaneyi'' is known from leaf and samara specimens which were recovered from a number of different formations in Western North America. The oldest occurrence is from the possibly Early Oligocene Gumboot Mountain flora of Southern Washington state followed by the Late Oligocene Kukak Bay flora in Alaska. In the early Miocene ''A. chaneyi'' is known from the Alaskan Kanalku Bay flora, Oregon Collawash and Little Butte flora. The Middle Miocene locations include the Skolai Creek flora of Alaska, Grand Coulee and Latah floras of Washington, Mascall flora and Succor Creek floras in Oregon and the Latah and Clarkia flora in Idaho. Further Middle Miocene occurrences in Nevada are the Thurston Ranch flora, Deadman Creek flora, Pyramid flora, Purple Mountain flora, Eastgate flora, and Middlegate floras. Late Miocene occurrences in Oregon are the Weyerhauser flora, Hidden Lake flora, Austin flora, Tipton flora, Stinking Water flora, and Trout Creek floras. Late Miocene occurrences in Idaho are the Cartwright Ranch flora, Horseshoe Bend flora, Alkali Creek flora and Trapper Creek flora. Based on the identified fossil occurrences ''A. chaneyi'' has a temporal range of approximately 20 million years, the longest identified for any fossil species in Western North America. The species '' Acer ferrignoi'' is a possible descendant species that survived in the Oregon Cascades until 7 million years ago. The

nomenclatural Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally ag ...

history for ''A. chaneyi'' is fairly complex: a number of different names have been applied to the fossils of different locations. The species was reviewed by

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 Jack A. Wolfe of the United States Geological Survey, Denver office and Toshimasa Tanai of

Hokkaido University , or , is a Japanese national university in Sapporo, Hokkaido. It was the fifth Imperial University in Japan, which were established to be the nation's finest institutions of higher education or research. Hokkaido University is considered ...

., in a 1987 paper in the ''Journal of the Faculty of Science, Hokkaido University''. The oldest name suggested for the fossils was ''Acer bendirei'' which was coined by

Leo Lesquereux Charles Léo Lesquereux (November 18, 1806 – October 25, 1889) was a Swiss-born bryologist and a pioneer of American paleobotany who studied the formation of peat bogs. Career Lesquereux was born in the town of Fleurier, located in the can ...

in 1883. The fossils used for his description of the species however were a mix of several different plants, and the type specimens were later transferred to the genus ''Platanus'' as ''P. bendirei''. The next oldest name, ''Acer gigas'', is from 1902 and was coined by

Frank Knowlton Frank Hall Knowlton (September 2, 1860 - November 22, 1926) was an American botanist, ornithologist and naturalist. Born in Vermont, he joined the Geological Survey and took an interest in fossil plants in the local lignite, later becoming a spec ...

for a fossil samara from the John Day formation. The fossil is missing the base of the fruit and the attachment scar, which is diagnostic for ''Acer'': thus it was rejected by Wolfe and Tanai. Similarly they rejected ''A. grahamensis'', for which the type specimen is also missing the attachment scar. They settled on ''A. chaneyi'' as the oldest valid species description, coined by Knowlton in 1926.

Description

Leaves of ''Acer chaneyi'' are simple in structure, with perfectly actinodromous vein structure and are widely

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

to orbiculate in shape. The leaves are deeply dissected, occasionally into three lobes but more typically into five. The upper lateral lobes are two thirds as long as the median lobe, and all the lateral lobes are elliptic in outline. The leaves have between five and eleven secondary veins which diverge from the basal region of the primary vein at angles ranging from 25° to 50°. The secondary veins arch towards the leaf margin in broadly convex to concave arches. The margins show large tooth-like serrations that are generally associated with smaller serrations on the basal side of the larger serrations. The samaras of ''A. chaneyi'' have moderately inflated nutlets and smoothly diverging veins which rarely

anastomose An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...

. The overall shape of the nutlet is narrowly elliptic, with a rounded tip and approximate length of and a width of . The wing ranges in overall length from and has a width range of . The paired samaras of the species have a 10° to 40° attachment angle and have veins originating in the attachment scar of the samara that run the length of the wing.

References

{{Taxonbar, from=Q19044190 chaneyi Plants described in 1926 Fossil taxa described in 1926 Oligocene plants Miocene plants Flora of North America Extinct flora of North America