''Sassafras hesperia'' 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 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

Lauraceae Lauraceae, or the laurels, is a plant family that includes the true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genera worldwide (Christenhusz & Byng 2016 ). They are dicotyledons, and occur ma ...

Distribution

The species is 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 (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,

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 ...

, United States and similar aged formations in

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, Canada, including the

Allenby Formation The Allenby formation is a sedimentary rock formation in British Columbia which was deposited during the Ypresian stage of the Early Eocene. It consists of conglomerates, sandstones with interbedded shales and coal. The shales contain an abun ...

near

Princeton Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nine ...

, the

McAbee Fossil Beds The McAbee Fossil Beds is a Heritage Site that protects an Eocene Epoch fossil locality east of Cache Creek, British Columbia, Canada, just north of and visible from Provincial Highway 97 / the Trans-Canada Highway ( Highway 1). The McAbee Fos ...

near

Kamloops Kamloops ( ) is a city in south-central British Columbia, Canada, at the confluence of the South flowing North Thompson River and the West flowing Thompson River, east of Kamloops Lake. It is located in the Thompson-Nicola Regional District, w ...

and

Driftwood Canyon Provincial Park Driftwood Canyon Provincial Park is a provincial park in British Columbia, Canada. Driftwood Canyon Provincial Park covers 23 ha of the Bulkley River Valley, on the east side of Driftwood Creek, a tributary of the Bulkley River, 10 km nort ...

near

Smithers Smithers is a surname of English origin. It derives from the Middle English term "smyther", referring to a metalsmith, and is thus related to the common occupational surname Smith. The name Smither is related. People *Alan Smithers (born 1938), ...

.Archibald, S.B., Greenwood, D.R., Smith, R.Y., Mathewes, R.W., and Basinger, J.F. 2012. Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)
Geoscience Canada, v. 38(4), p. 155–164
''S. hesperia'' is related to three modern species, '' S. albidum'', which is native to the eastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, '' S. tzumu'' native to central

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, and '' S. randaiense'' native to

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

. The modern species form a noted

disjunct distribution In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...

History

The original

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 ...

of the new species 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 ...

Edward W. Berry Edward Wilber Berry (February 10, 1875 – September 20, 1945) was an American paleontologist and botanist; the principal focus of his research was paleobotany. Early life Berry was born February 10, 1875, in Newark, New Jersey, and finished hig ...

, based on a

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 ...

leaf specimen, was published in 1929. When first published the holotype specimen's type locality was misidentified as being part of the

Latah Formation The Latah Formation is a series of late Miocene lacustrine sedimentary deposits which outcrop in eastern Washington and northwestern Idaho. The lake beds are interbedded with igneous rock of the Columbia River Basalt Group. The formation was ...

of Spokane. Roland W. Brown (1937) corrected the type locality to the older Republic area strata, but occasional confusion as to the species age still occurred: notably

Daniel I. Axelrod Daniel Isaac Axelrod (July 16, 1910 – June 2, 1998) was an American paleoecologist specializing in Tertiary Cordilleran floras, in particular correlating fossil evidence of specific floras with climate change indicators. Biography He received ...

(1966) in his paper on the Copper Basin flora of Nevada considered the age of ''S. hesperia'' as Oligocene. Working from specimens collected in the Republic, Washington area in the early 1980s, the species was redescribed in 1987 by

Jack A. Wolfe Jack Albert Wolfe (1936–2005) was a United States Geological Survey paleobotanist and paleoclimatologist best known for his studies of Tertiary climate in western North America through analysis of fossil A fossil (from Classical Latin ...

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 ...

. Wolfe and Wehr noted ''S. hesperia'' to be one of the most common dicots in the Klondike Mountain Formation, that it occurs in the related

and Joseph Creek floras, and in the

Thunder Mountain flora Thunder is the sound caused by lightning. Depending upon the distance from and nature of the lightning, it can range from a long, low rumble to a sudden, loud crack. The sudden increase in temperature and hence pressure caused by the lightning pr ...

of Idaho, of similar age. However they reject the assignment to ''S. hesperia'' of the single known ''Sassafras'' species leaf from the Eocene

Florissant formation The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and ...

. Wolf and Wehr also note that the early Oligocene '' S. ashleyi'' is closely related and may have evolved from ''S. hesperia''.

Description

''Sassafras hesperia'' leaves are large, with fossils over known. the species appears to have been possibly

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

, based on the notably thick leaf remains, thicker than the younger ''S. ashleyi'' and '' S. columbiana''. This contrasts with modern ''Sassafras'' species, which are

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

, suggesting that an evergreen state is ancestral in ''Sassafras''.

References

{{Taxonbar, from=Q7425747 Lauraceae Prehistoric angiosperms Ypresian plants of North America Eocene life of North America Extinct flora of North America Fossil taxa described in 1987 Plants described in 1987 Klondike Mountain Formation Chu Chua Formation