''Carpinus perryae'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

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 ...

hornbeam Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. Origin of names The common English name ''hornbeam' ...

known 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 ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

s found in the

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation, named for the type location designated in 1962, Klondike Mountain north of Republic, Wash ...

deposits of northern

Washington state Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...

, dated to the early

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

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

stage. Based on described features, ''C. perryae'' is the oldest definite species in the genus ''Carpinus''.

History and classification

''Carpinus perryae'' was described from two

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

s, 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 ...

and

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 ...

fertile bracts, numbered UWBM 71171, specimen A and B respectively. Both

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason fo ...

specimens are preserved together on a single rock slab that is part of the

Burke Museum The Burke Museum of Natural History and Culture (Burke Museum) is a natural history museum in Seattle, Washington, in the United States. Established in 1899 as the Washington State Museum, it traces its origins to a high school naturalist club fo ...

paleobotanical collections. Found at the

s UWBM site B2737, which is designated the type locality, the fossils were described 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 Pigg, Manchester, and

Wehr Wehr may refer to: * WEHR, a former radio station owned by Penn State University * Wehr, Baden-Württemberg, Germany * Wehr, Rhineland-Palatinate, Germany * Wehr, a village in Selfkant, North Rhine-Westphalia, Germany People with the surname * D ...

(2003) along with ''

Corylus johnsonii ''Corylus johnsonii'' is an extinct species of hazel known from fossil fruits found in the Klondike Mountain Formation deposits of northern Washington state, dated to the early Eocene Ypresian stage (). Based on described features, ''C. johnsonii ...

'' and '' Palaeocarpinus barksdaleae''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''perryae'' was coined as a

matronym A matronymic is a personal name based on the given name of one's mother, grandmother, or any female ancestor. It is the female equivalent of a patronymic. Around the world, matronymic surnames are far less common than patronymic surnames. In s ...

recognizing Madilane Perry for her work founding the

Stonerose Interpretive Center The Stonerose Interpretive center & Eocene Fossil Site is a 501c(3) non-profit public museum and fossil dig located in Republic, Washington. The center was established in 1989 and houses fossils that have been featured in ''National Geographic M ...

Republic, 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. It was the largest mining camp in the Republic Mining Distr ...

. Pigg, Manchester, and Wehr (2003) noted at the time of description that ''Carpinus perryae'' was the oldest confirmed

fossil placed in ''

Carpinus Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. Origin of names The common English name ''hornbea ...

'', a status affirmed by Forest ''et al'' (2005) who used ''C perryae'' as a fossil calibration point for phylogenetic analysis of

Betulaceae Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the t ...

. Based on six morphological character states that are present in the fossils ranging from nutlet and bract shape to serration of the bract, ''C. perryae'' was determined to be most similar to species in ''Carpinus'' subgenus ''Carpinus'', such as ''

Carpinus monbeigiana Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. Origin of names The common English name ''hornbeam' ...

''. A noted distinction between the modern species and the fossils is the overall bract shape, ovate in modern species, but obovate in ''C. perryae''.

Distribution and paleoecology

''Carpinus perryae'' is known from a single location in the

Eocene Okanagan Highlands The Eocene Okanagan Highlands or Eocene Okanogan Highlands are a series of Early Eocene geological formations which span a transect of British Columbia, Canada, and Washington state, United States. Known for a highly diverse and detailed Paleoflo ...

, an outcrop of the

Republic A republic () is a "state in which power rests with the people or their representatives; specifically a state without a monarchy" and also a "government, or system of government, of such a state." Previously, especially in the 17th and 18th c ...

. The formation preserves an upland lake system surrounded by a mixed conifer–broadleaf forest with nearby volcanism. The pollen flora has notable elements of

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...

and

golden larch ''Pseudolarix amabilis'' is a species of coniferous tree in the pine family Pinaceae. The species is commonly known as golden larch, but being more closely related to ''Keteleeria'', ''Abies'' and ''Cedrus'', is not a true larch (''Larix''). ' ...

, and distinct trace amounts of fir,

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 (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

cypress Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the ...

, and

palm Palm most commonly refers to: * Palm of the hand, the central region of the front of the hand * Palm plants, of family Arecaceae **List of Arecaceae genera * Several other plants known as "palm" Palm or Palms may also refer to: Music * Palm (ba ...

. Wolfe and Tanai (1987) interpreted the forest climate to have been

microthermal In climatology, the term microthermal is used to denote the continental climates of Eurasia and North America. Etymology The word ''microthermal'' is derived from two Greek words meaning "small" and "heat". This is misleading, however, since the t ...

, having distinct seasonal temperature swings which dipped below freezing in the winters. However, further study has shown the lake system was surrounded by a warm temperate ecosystem that likely had a mesic upper microthermal to lower mesothermal climate, in which winter temperatures rarely dropped low enough for snow, and which were seasonably equitable. The Okanagan Highlands paleoforest surrounding the lakes have been described as precursors to the modern

temperate broadleaf and mixed forests Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These fo ...

of Eastern North America and Eastern Asia. Based on the fossil biotas, the lakes were higher and cooler then the

coeval {{Short pages monitor