''Pinus latahensis'' 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
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
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 sin ...
in the
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae.
''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...
family
Pinaceae
The Pinaceae (), or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, Pinyon_pine, piñons,
larches, pines and spruces. The family is incl ...
. 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 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 ...
deposits of northern Washington state, United States, and southern British Columbia, Canada.
Age
''Pinus latahensis'' was first described by
Edward W. Berry in 1929 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 f ...
recovered from shale outcrops in the
Republic, Washington area.
When published the holotype specimen's
type locality at Republic was misidentified as being an extension of the younger
Latah Formation, located around the
Spokane region, which was then considered to be of
Late Miocene
The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
age.
Roland W. Brown identified that the Republic floras is of an older age and not part of the Latah formation in 1937.
The Oligocene age was followed by
Herman Becker (1961) while discussing the Oligocene
Ruby Flora of Montana
and
Jack Wolfe (1965) in discussing the Miocene Fingerrock Wash Flora of Nevada.
In a written communication , Brown again revised the age still older, stating fossils found in the area of Mount Elizabeth, northeast of Republic indicated an
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
age. This age was used by R.L. Parker and J. A. Calkins (1964) on their assessment of the Curlew Quadrangle of Ferry County.
Since then the fossil-bearing strata of the
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 ...
have been
radiometrically dated, to give a current estimate of 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 ...
, the mid stage of the early Eocene,.
Distribution and paleoenvironment
In his 1955 review of conifer fossils found in the
Princeton coal fields of
British Columbia
British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...
,
Chester A. Arnold noted the marked similarities between the Klondike Mountain and Allenby Formations and interpreted the shared taxa of the formations to indicated that the Klondike Mountain Formation was of Oligocene age like the Allenby Formation was thought to be at the time.
This similarity was also noted and commented on by
Charles Miller (1975) who agreed the Republic and Princeton floras were coeval, and of Eocene age.
Both sites represent upland lake systems that were surrounded by a warm temperate ecosystem with nearby volcanism.
The highlands 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 ...
of Eastern North America and Eastern Asia. Based on the fossil
biotas the lakes were higher and cooler then the