''Acer douglasense'' 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

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 ...

. The species is solely known from the

Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...

sediments exposed in

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 ...

Kodiak Island Borough, Alaska Kodiak Island Borough (russian: Остров Кадьяк) is a borough in the U.S. state of Alaska. At the 2020 census, the population was 13,101, down from 13,592 in 2010. The borough seat is Kodiak. Geography The borough has a total are ...

. It is the type species for the extinct section ''Douglasa''.

Type locality

The species was described from a group of leaf specimens found in the West Foreland Formation which is part of the Kenai Group. Sediments of the formation span are typically

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

clastic

sedimentary Sedimentary rocks are types of rock (geology), rock that are formed by the accumulation or deposition of mineral or organic matter, organic particles at Earth#Surface, Earth's surface, followed by cementation (geology), cementation. Sedimentati ...

rocks dating from the

Late Paleocene The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

to early Eocene with ''A. douglasense'' only found in the Eocene age section.

History and classification

''Acer douglasense'' was described from several specimens, 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 ...

, number "USNM 396006", and a group of

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 ...

s. The holotype and paratypes are 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

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 ...

, part of the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

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. douglasense'' 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 ...

''douglasense'' in recognition of the type locality on Cape Douglas. ''A. douglasense'' is the second oldest occurrence of the maple genus, with the oldest being '' A. alaskense'' from the Latest Paleocene Chickaloon Formation. In their type description Wolfe and Tanai designated ''A. douglasense'' as the type and only species for the extinct ''Acer'' section ''Douglasa''.

Description

Leaves of ''Acer douglasense'' are simple in structure and a generally oval shape. The deeply five lobed structure and tertiary vein structure is very similar to the modern species '' A. spicatum''. However the secondary veins are a combination of alternating craspedodromous veins and forking veins. The related living Sapindaceae genera ''

Cardiospermum ''Cardiospermum'' is a genus of approximately 14 species in the soapberry family, Sapindaceae, which are native to the American, Indian, and African tropics. The genus name is derived from the Greek words καρδία, meaning "heart," and σπ� ...

'' and ''

Serjania ''Serjania'' is a genus of flowering plants in the soapberry family, Sapindaceae. The name honours French Minim friar Philippe Sergeant. Selected species Formerly placed here * ''Paullinia cururu ''Paullinia'' is a genus of flowering s ...

'' plus the extinct genus '' Bohlenia'' also have a similar alternating pattern of secondary veins.

References

{{Taxonbar, from=Q2822955 douglasense Plants described in 1987 Fossil taxa described in 1987 Eocene plants Extinct flora of North America