Acer washingtonense
Encyclopedia
Acer washingtonense is an extinct maple
species
in the family Sapindaceae
described from one fossil
leaf
and four fossil samara
s. The species is solely known from the Early Eocene sediments exposed in northeast Washington State, USA. It is one of three species belonging to the extinct section Torada.
identified as Burke Museum of Natural History and Culture
location UWBM B2737. The third samara fossil is from the Burke Museum location UWBM A0307 located within the town of Republic itself and the last samara was recovered from Resner Canyon, National Museum of Natural History
location USNM 11018. Both UWBM B2737 and UWBM A0307 are in the Republic Graben while USNM 11018 is in the Toroda Creek Graben. Each of the sites are considered outcroppings of early Eocene, Ypresian
, shale belonging to the Klondike Mountain Formation
. The Klondike Mountain Formation, along with site of the same age in British Columbia
preserve upland temperate floras which were first interpreted as being Microthermal
, however further study has shown them to be more mesothermal
in nature. The plant community preserved in the Klondike Mountain formation is a mixed conifer-broad leaf forest with large pollen elements of birch
and golden larch, but also having notable traces of fir
, spruce
, cypress
, and palm
.
The species was described from a group of specimens, the holotype, number "UWBM 56253 A,B" and the paratype
s "UWBM 56255", "UWBM 71135 A,B" and "UWBM 54308" are currently preserved in the paleobotanical
collections housed at the Burke Museum, part of the University of Washington
in Seattle while the paratype, "USNM 396011", is in the paleobotanical collections of the National Museum of Natural History
, part of the Smithsonian Institution
in Washington, D.C.
. The specimens were studied by paleobotanists Jack A. Wolfe
of the United States Geological Survey, Denver office
and Toshimasa Tanai of Hokkaido University
. Wolfe and Tanai published their 1987 type description for A. toradense in the Journal of the Faculty of Science, Hokkaido University. The etymology
of the chosen specific name
washingtonense is in recognition of the type locality in Northeastern Washington State. A. washingtonense is one of three species assigned to the extinct section Torada and is designated the type species for the section. The three members of the section A. stonebergae
, A. toradense
, and A. washingtonense were known only from the Republic and Princeton fossil localities when first described. Of the three species, both A. stonebergae and A. toradense are only known from the samara fossils, and only A. washingtonense has been described from both leaves and samaras. The three are among a number of Acer species described from the Republic and Princeton sites by Wolfe and Tanai.
and a generally wide elliptic shape. The leaves are shallowly three-lobed, with five primary veins and is 5 centimetres (2 in) wide by an estimated 7.5 centimetres (3 in) long in overall dimension. A. washingtonense has a simple structure to the teeth that is similar to the Alaskan fossil species A. alaskense
and A. douglasense
and the modern species A. spicatum. The samaras have distinct bifurcating ridges on the nutlet which are unique to section Torada. The overall shape of the samara is ovoid with a average length of up to 2.6 centimetres (1 in) and a wing width of 0.7 centimetre (0.275590551181102 in). The paired samaras for A. washingtonense have a 45° attachment angle and the attachment scar on the nutlet is 0.4 centimetre (0.15748031496063 in). While very similar in morphology to A. toradense, the two possibly related species can be separated by the coarse reticulum of veins which is found on A. toradense and not A. washingtonense. The samaras of A. stonebergae are distinguishable from both A. toradense and A.washingtonense by their notably larger overall size.
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 one fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
leaf
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
and four fossil samara
Samara (fruit)
A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent . It is a winged achene...
s. The species is solely known from the Early Eocene sediments exposed in northeast Washington State, USA. It is one of three species belonging to the extinct section Torada.
History and classification
Acer washingtonense was described from a lone leaf specimen and four complete fruit specimens which were recovered from three different locations. The lone leaf and two of the samara's were found in an outcrop of shale on Knob Hill north of Republic, WashingtonRepublic, Washington
Republic is a city in Ferry County, Washington, United States. The population was 1,073 at the 2010 census, a 12.5% increase over the 2000 Census. It is the county seat of Ferry County.-History:...
identified as Burke Museum of Natural History and Culture
Burke Museum of Natural History and Culture
The Burke Museum of Natural History and Culture has been a Washington state museum since 1899. It is located at the University of Washington campus at the intersection of N.E. 45th Street and 17th Avenue N.E. in Seattle, Washington, USA, in the University District. It is the only major natural...
location UWBM B2737. The third samara fossil is from the Burke Museum location UWBM A0307 located within the town of Republic itself and the last samara was recovered from Resner Canyon, 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....
location USNM 11018. Both UWBM B2737 and UWBM A0307 are in the Republic Graben while USNM 11018 is in the Toroda Creek Graben. Each of the sites are considered outcroppings of early Eocene, Ypresian
Ypresian
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between and , is preceded by the Thanetian age and is followed by the Eocene Lutetian age....
, shale belonging to the Klondike Mountain Formation
Klondike Mountain Formation
The Klondike Mountain Formation is an early Eocene geologic formation that records the sedimentation in the southern most of a string of highland subtropical/Temperate lakes in Washington state and British Columbia. The formation is best known for exceptionally well preserved plant and insect fossils...
. The Klondike Mountain Formation, along with site of the same age in British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
preserve upland temperate floras which were first interpreted as being Microthermal
Microthermal
In climatology, the term microthermal is used to denote the continental climates of Eurasia and North America.The word microthermal is derived from two Greek words meaning "having little heat." This is misleading, however, since the term is intended to describe only the temperature conditions that...
, however further study has shown them to be more mesothermal
Mesothermal
In climatology, the term mesothermal is used to refer to certain forms of climate found typically in the Earth's Temperate Zones. It has a moderate amount of heat, with winters not cold enough to sustain snow cover...
in nature. The plant community preserved in the Klondike Mountain formation is a mixed conifer-broad leaf forest with large pollen elements of birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
and golden larch, but also having notable traces of fir
Fir
Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...
, spruce
Spruce
A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...
, cypress
Taxodium
Taxodium is a genus of one to three species of extremely flood-tolerant conifers in the cypress family, Cupressaceae...
, and palm
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
.
The species was described from a group of specimens, the holotype, number "UWBM 56253 A,B" and the 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 "UWBM 56255", "UWBM 71135 A,B" and "UWBM 54308" are currently 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 Burke Museum, part of the University of Washington
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
in Seattle while the paratype, "USNM 396011", is in the paleobotanical collections of 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. toradense 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...
washingtonense is in recognition of the type locality in Northeastern Washington State. A. washingtonense is one of three species assigned to the extinct section Torada and is designated the type species for the section. The three members of the section A. stonebergae
Acer stonebergae
Acer stonebergae is an extinct maple species in the family Sapindaceae described from two fossil samaras. The species is solely known from the Early Eocene sediments exposed in northeast Washington State, USA and the adjacent area of south central British Columbia, Canada...
, A. toradense
Acer toradense
Acer toradense is an extinct maple species in the family Sapindaceae described from two fossil samaras. The species is solely known from the Early Eocene sediments exposed in northeast Washington State, USA and the adjacent area of south central British Columbia, Canada...
, and A. washingtonense were known only from the Republic and Princeton fossil localities when first described. Of the three species, both A. stonebergae and A. toradense are only known from the samara fossils, and only A. washingtonense has been described from both leaves and samaras. The three are among a number of Acer species described from the Republic and Princeton sites by Wolfe and Tanai.
Description
Leaves of Acer washingtonense are simple in structure and with perfectly actinodromus vein structureLeaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
and a generally wide elliptic shape. The leaves are shallowly three-lobed, with five primary veins and is 5 centimetres (2 in) wide by an estimated 7.5 centimetres (3 in) long in overall dimension. A. washingtonense has a simple structure to the teeth that is similar to the Alaskan fossil species 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...
and A. douglasense
Acer douglasense
Acer douglasense is an extinct maple species in the family Sapindaceae described from fossil leaves. The species is solely known from the Early Eocene sediments exposed in Katmai National Park and Preserve, Kodiak Island Borough, Alaska...
and the modern species A. spicatum. The samaras have distinct bifurcating ridges on the nutlet which are unique to section Torada. The overall shape of the samara is ovoid with a average length of up to 2.6 centimetres (1 in) and a wing width of 0.7 centimetre (0.275590551181102 in). The paired samaras for A. washingtonense have a 45° attachment angle and the attachment scar on the nutlet is 0.4 centimetre (0.15748031496063 in). While very similar in morphology to A. toradense, the two possibly related species can be separated by the coarse reticulum of veins which is found on A. toradense and not A. washingtonense. The samaras of A. stonebergae are distinguishable from both A. toradense and A.washingtonense by their notably larger overall size.