Acer douglasense is an extinct maple

Maple

Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in the family Sapindaceae

Sapindaceae

Sapindaceae, also known as the soapberry family, is a family of flowering plants in the order Sapindales. There are about 140-150 genera with 1400-2000 species, including maple, horse chestnut and lychee....

 described from fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 leaves

Leaves

-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...

. The species is solely known from the Early Eocene sediments exposed in Katmai National Park and Preserve

Katmai National Park and Preserve

Katmai National Park and Preserve is a United States National Park in southern Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park covers , being roughly the size of Wales. Most of this is a designated wilderness area, including of the park...

, Kodiak Island Borough, Alaska

Kodiak Island Borough, Alaska

-National protected areas:* Alaska Maritime National Wildlife Refuge ** Barren Islands** Semidi Wilderness*** Semidi Islands** Trinity Islands*** Sitkinak Island*** Tugidak Island...

. 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

Kenai Group

Kenai Group is a name given by Dall and Harris to sedimentary rocks in the Cook Inlet basin in Alaska. These rocks are instead called the Kenai Formation by several other authors....

. Sediments of the formation span are typically volcanoclastic

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 sedimentary rocks dating from the Late Paleocene 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

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

, number "USNM 396006", and a group of paratype

Paratype

Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...

s. The holotype and paratypes are preserved in the paleobotanical

Paleobotany

Paleobotany, also spelled as palaeobotany , is the branch of paleontology or paleobiology dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments , and both the evolutionary history of plants, with a...

 collections housed at the National Museum of Natural History

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. Admission is free and the museum is open 364 days a year....

, part of the Smithsonian Institution

Smithsonian Institution

The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...

 in Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

.

The specimens were studied by paleobotanists Jack A. Wolfe

Jack A. Wolfe

Jack Albert Wolfe was an American paleontologist best known for his studies of Tertiary climate in western North America through analysis of fossil angiosperm leaves.-External links:...

 of the United States Geological Survey, Denver office

United States Geological Survey

The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...

 and Toshimasa Tanai of Hokkaido University

Hokkaido University

Hokkaido University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:...

. Wolfe and Tanai published their 1987 type description for A. douglasense in the Journal of the Faculty of Science, Hokkaido University. The etymology

Etymology

Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

 of the chosen specific name

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 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

Acer alaskense

Acer alaskense is an extinct maple species in the family Sapindaceae described from a fossil leaf. The species is solely known from the Latest Paleocene sediments exposed in the Matanuska River Valley, Matanuska-Susitna Borough, Alaska...

from the Latest Paleocene

Paleocene

The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

 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. This combination only seen in the Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 maple species A. orbum. The related living Sapindaceae genera Cardiospermum

Cardiospermum

Cardiospermum is a genus of approximately 14 species in the soapberry family, Sapindaceae, which are native to the American, Indian, and African tropics...

and Serjania

Serjania

Serjania is a genus of flowering plants in the soapberry family, Sapindaceae. The name honours either French monk Philippe Sergeant or French friar Paul Serjeant.-Selected species:-Formerly placed here:...

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