''Corylopsis reedae'' is an extinct species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

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 syste ...

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 ...

leaves found in the early

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

Klondike Mountain Formation 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 ...

. ''C. readae'' is one of the oldest occurrences of the winter-hazel genus ''

Corylopsis ''Corylopsis'' is a genus of nearly 30 species of shrubs in the witch hazel family, Hamamelidaceae, native to eastern Asia with the majority of species endemic to China but with some also in Japan, Korea, and the Himalayas. This genus is also ...

'', 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 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 ...

-aged Klondike Mountain Formation that outcrops in Republic,

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. T ...

. 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 potassiumargon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measurements, while the newer ...

, 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, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattl ...

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

holotype specimen 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 ...

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

Seattle, Washington Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region ...

. The specimen was 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 ...

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

Wesley C. Wehr Wesley Conrad Wehr (April 17, 1929 – April 12, 2004) was an American paleontology, paleontologist and artist best known for his studies of Cenozoic paleobotany, fossil floras in western North America, the Stonerose Interpretive Center, and as ...

of the

Burke Museum of Natural History and Culture 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 ...

in Seattle. Radtke, Pigg and Wehr published their 2005

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 ''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 ()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 specific name ''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