''Acer smileyi'' 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 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 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 the

late Oligocene The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

sediments exposed in the states of

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 ...

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, and

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, USA. It is one of several extinct species placed in the living section '' Parviflora''.

History and classification

The eight leaf specimens used to describe ''Acer smileyi'' were recovered from six different sites. The oldest group of specimens was recovered from the late Oligocene age Kukak Bay flora exposed on the

Katmai National Park and Preserve Katmai National Park and Preserve is an American national park and preserve in southwest Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park and preserve encompass , which is between the sizes of Connecticut a ...

along the

Shelikof Strait Shelikof Strait (russian: Пролив Шелихова) is a strait on the southwestern coast of the U.S. state of Alaska between the Alaska mainland to the west and Kodiak and Afognak islands to the east. Shelikof Strait separates the mainland ...

in Alaska. Another paratype leaf was recovered from outcrops of the Langhian age Capps Glacier flora northwest of Kukak Bay in Kenai Peninsula County. A younger paratype of Middle Miocene age was recovered from the Trout Creek Formation in

Harney County Harney County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 7,495, making it the sixth-least populous county in Oregon. The county seat is Burns. Established in 1889, the county is named in ho ...

of southeastern Oregon. The southernmost occurrence of the species is at 49 camp in northwestern

Washoe County, Nevada Washoe County () is a county in the U.S. state of Nevada. As of the 2020 census, the population was 486,492, making it Nevada's second-most populous county. Its county seat is Reno. Washoe County is included in the Reno, NV Metropolitan Statist ...

where the

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

Upper Cedarville Formation is exposed. The youngest and easternmost of the known occurrences is near

Clarkia, Idaho Clarkia is a small unincorporated community in the southwestern corner of Shoshone County, Idaho. It is surrounded by publicly and privately managed forest lands of Douglas-fir, Ponderosa Pine, and Western Larch. Located just to the east of ...

, where sediments of the

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 a ...

age Lake Clarkia is exposed. One additional Langhian paratype is known from the

Moose Mountain Flora The moose (in North America) or elk (in Eurasia) (''Alces alces'') is a member of the New World deer subfamily and is the only species in the genus ''Alces''. It is the largest and heaviest extant species in the deer family. Most adult mal ...

, formerly known as the Cascadia flora exposed near the former town of Cascadia in western Oregon. In addition to the leaf specimens a series of paratype specimens were described for the associated samaras recovered at the Clarkia site and the '49 camp site. The type specimens for ''Acer smileyi'' are placed into three different repositories. 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 several ...

leaf, three of the

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 nor a syntype). Of ...

leaves and all five of the paratype samaras are currently preserved in the

paleobotanical 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 ...

collections housed at 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 and ...

, in

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 Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emer ...

. Two other paratype leaves are housed in the

National Museum of Natural History The National Museum of Natural History 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. In 2021, with 7 ...

, Washington, a part of the Smithsonian, while the last paratype leaf is part of the University of Michigan Museum of Paleontology collections in

Ann Arbor, Michigan Ann Arbor is a city in the U.S. state of Michigan and the county seat of Washtenaw County, Michigan, Washtenaw County. The 2020 United States census, 2020 census recorded its population to be 123,851. It is the principal city of the Ann Arbor ...

. The specimens were studied 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 ...

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 A fossil (from Classical Latin ...

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 ...

. Wolfe and Tanai published their 1987

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

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

''smileyi'' is in recognition of Charles J. Smiley for his extensive efforts studying the Clarkia sites and their flora.

Description

Leaves of ''Acer smileyi'' are simple in structure, with perfectly actinodromous vein structure and are generally orbiculate to suborbiculate in shape. The leaves are five-lobed with the basal two lobes small while the upper lateral lobes are almost as long as the median lobe and all lobes being triangular in outline. The leaves have five primary veins and range between long by wide in overall dimensions. ''A. smileyi'' has small teeth while the lobes have a distinct and complex bracing of veins formed by the joining of two external secondary veins. The combination of morphological features is not found in any modern species besides '' A. nipponicum'' and so ''A. smileyi'', along with the extinct '' A. browni'', is placed into the section ''Parviflora''. The samaras of ''A. smileyi'' have a notably inflated nutlet and acutely diverging veins which rarely reconnect (''

anastomise 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 norma ...

''). The overall shape of the nutlet is circular to elliptic with the average length of the samara up to and a wing width of . The paired samaras of the species have a 25° to 30° attachment angle and the distal region of the nutlet and wing forming distinct u-shaped shallow sulcus. ''A. smileyi'' is similar to ''A. browni'' but the two can be distinguished from each other by the size of the basal lobes which are larger in ''A. smileyi''. The more attenuated teeth of ''A. smileyi'' are very similar in morphology to ''A. nipponicum'' indicating the two to be closer in relation to each other than to ''A. browi''.

References

{{Taxonbar, from=Q4673175 smileyi Prehistoric angiosperms Plants described in 1987 Fossil taxa described in 1987 Miocene plants Extinct flora of North America Fossils of the United States