''Corylopsis reedae'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the family

Hamamelidaceae Hamamelidaceae, commonly referred to as the witch-hazel family, is a family of flowering plants in the order Saxifragales. The clade consists of shrubs and small trees positioned within the woody clade of the core Saxifragales. An earlier system ...

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 preserve ...

leaves found in the early

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

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington (state), Washington state. The formation is composed of volcanic rocks in the upper unit and volcanic plus lacu ...

deposits of northern

Washington state Washington, officially the State of Washington, is a state in the Pacific Northwest region of the United States. It is often referred to as Washington State to distinguish it from the national capital, both named after George Washington ...

. ''C. readae'' is one of the oldest occurrences of the winter-hazel genus '' Corylopsis'', which includes between seven and thirty species, all found in Asia. Fossils from two other occurrences are of similar age to ''C. readae'', with Paleocene specimens from Greenland being placed in the form taxon ''Corylopsiphyllum'' and an Eocene Alaskan fossil being included in ''Corylopsis'' without species placement.

History and classification

''Corylopsis reedae'' is represented by a single counterpart

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 f ...

specimen from the

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 ...

-aged

that outcrops in

Republic A republic, based on the Latin phrase ''res publica'' ('public affair' or 'people's affair'), is a State (polity), state in which Power (social and political), political power rests with the public (people), typically through their Representat ...

Ferry County, Washington Ferry County is a county located on the northern border of the U.S. state of Washington. As of the 2020 census, the population was 7,178, making it the fourth-least populous county in Washington. The county seat and largest city is Republic. ...

. The age of the formation is based on

Argon–argon dating Argon–argon (or 40Ar/39Ar) dating is a radiometric dating method invented to supersede Potassium-argon dating, potassiumargon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measur ...

, which has returned a date of 49.4 ±0.5 million years old. The fossil was recovered from the "Corner lot",

University of Washington The University of Washington (UW and informally U-Dub or U Dub) is a public research university in Seattle, Washington, United States. Founded in 1861, the University of Washington is one of the oldest universities on the West Coast of the Uni ...

site UWBM A0307, located within the city limits of Republic. The

holotype specimen A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was Species description, formally described. It is either the single such physical example (or illus ...

for ''Corylopsis reedae'' is numbered UWBM 71085 and currently preserved in the paleobotanical collections of

Seattle, Washington Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...

. The specimen was studied by

paleobotanist Paleobotany or palaeobotany, also known as paleophytology, is the branch of botany dealing with the recovery and identification of plant fossils from geological contexts, and their use for the biological reconstruction of past environments (pale ...

s Meghan G. Radtke and Kathleen B. Pigg of the School of Life Sciences,

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

, and Wesley C. Wehr of the

Burke Museum of Natural History and Culture The Burke Museum of Natural History and Culture (commonly as Burke Museum) is a natural history museum on the campus of the University of Washington, in Seattle, Washington, United States. It is administered by the UW College of Arts and Scien ...

in Seattle. Radtke, Pigg and Wehr published their 2005

type description A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

for ''C. readae'' in the ''

International Journal of Plant Sciences The ''International Journal of Plant Sciences'' covers botanical research including genetics and genomics, developmental and cell biology, biochemistry and physiology, morphology and structure, systematics, plant-microbe interactions, paleobotany, ...

''. The

etymology Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

of the

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 ...

''readae'' was derived from Katherine ("Kitty") M. Reed in honor of her contributions to the Tertiary stratigraphy and paleontology of the Pacific northwest.

Description

The specimen used for the description of ''C. readae'' is an incomplete simple, elliptical leaf. The preserved section of leaf is long with the overall length estimated to have been approximately and is at the widest point. The base of the specimen is slightly asymmetric with a 102° angle, also slightly obtuse. The pinnate secondary veins diverge from the primary vein at an angles ranging from 18° near the base to 13°-14° nearing the center area of the leaf. They form a craspedodromous pattern with the secondaries alternating along the primary vein. The basal most secondary veins produce numerous compound agrophic veins. The preserved teeth on the fossil show simple teeth with straight bases and concave apexes, though due to the lack of full teeth the overall length of the teeth is not known.

References

{{Taxonbar, from=Q21396536 Corylopsis readae Flora of Washington (state) Fossil taxa described in 2005 Plants described in 2005 Ypresian plants of North America Extinct flora of North America Klondike Mountain Formation