''Torreya clarnensis'' 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 ...

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

in the

yew Yew is a common name given to various species of trees. It is most prominently given to any of various coniferous trees and shrubs in the genus ''Taxus'': * European yew or common yew (''Taxus baccata'') * Pacific yew or western yew (''Taxus br ...

family

Taxaceae Taxaceae (), commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species. Description They are many-bran ...

solely known from the

middle 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'', "dawn ...

sediments exposed in north central

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

. The species was first described from a series of isolated

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 ...

seeds in

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

History and classification

''Torreya clarnensis'' has been identified from a single location in the

Clarno Formation Clarno may refer to: Locations * Clarno, Oregon * Clarno, Wisconsin ** Clarno (community), Wisconsin *Clarno Township, Lake County, South Dakota Lake County is a county in the U.S. state of South Dakota. As of the 2020 United States Census, t ...

, the Clarno nut beds, type locality for both the formation and the species. The nut beds are approximately east of the unincorporated community of

Clarno, Oregon Clarno is an unincorporated community in Wasco County, Oregon, United States. It is located along Oregon Route 218 near the John Day River. History The community was named after Andrew Clarno, an early settler. The Clarno post office was estab ...

and currently considered to be middle Eocene in age, based on averaging zircon fission track

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

which yielded an age of 43.6 and 43.7 ± 10

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

and

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 yielded a 36.38 ± 1.31 to 46.8 ± 3.36 mya date. The average of the dates resulted in an age range of 45 to 43 mya. The beds are composed of silica and calcium carbonate cemented

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

aceous sandstones, siltstones, and conglomerates which preserve either a lake delta environment, or alternatively periodic floods and volcanic mudflows preserved with hot spring activity. The species was described from a series of

type specimens In biology, a type is a particular 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 anchor or centralizes t ...

, 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 ...

specimen UF6510, which is currently preserved in the

paleobotanical 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 ...

collections of the

University of Florida The University of Florida (Florida or UF) is a public land-grant research university in Gainesville, Florida. It is a senior member of the State University System of Florida, traces its origins to 1853, and has operated continuously on its ...

and two

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 ...

specimens, both of which are part of the

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. It has free admission and is open 364 days a year. In 2021, with 7 ...

collections in

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

The fossils were part of approximately 20,000 specimens collected from 1942 to 1989 by Thomas Bones, A. W. Hancock, R. A. Scott, Steven R. Manchester, and a number of high school students. The ''Torreya clarnensis'' specimens were 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 ...

Steven R. Manchester of the University of Florida. He published his 1994

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 ''T. masonii'' in the Journal ''

Palaeontographica Americana The Paleontological Research Institution, or PRI, is a paleontological organization in Ithaca, New York, with a mission including both research and education. PRI is affiliated with Cornell University, houses one of the largest fossil collecti ...

''. 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 ...

''clarnensis'' was chosen in recognition of the type locality, the Clarno Formation.

Description

The seeds of ''Torreya clarnensis'' are

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a b ...

and bilaterally symmetrical with a pointed tip and base. The seeds have an overall length raging between and a width between . The seeds are identified as from a ''Torreya'' species by several features of the exterior morphology. The overall cross section shape is

obovate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

, with an acutely rounded base where an

aril An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ...

would have attached, a keeled apex, and a pair of vascular scars near the tip. The seeds have a pair of vascular pores positioned on the upper and lower surfaces approximately one third of the way below the apex. The apical area of the seed is defined by a keel created by the edges of the upper and lower faces.

References

{{Taxonbar, from=Q16759536 clarnensis Eocene plants Eocene life of North America Flora of Oregon Paleogene geology of Oregon Plants described in 1994 Fossil taxa described in 1994 John Day Fossil Beds National Monument Extinct flora of North America Prehistoric trees Clarno Formation