''Sequoiadendron chaneyi'' 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 ...

of tree in the

Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdio ...

genus ''

Sequoiadendron ''Sequoiadendron'' is a genus of evergreen trees, with two species, only one of which survives to the present: * ''Sequoiadendron giganteum'', extant, commonly known as wellingtonia, giant redwood and giant sequoia, growing naturally in the Sie ...

''. Known from

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

fossils found in Nevada and California, ''S. chaneyi'' is the oldest species of ''Sequoiadendron''. The common use of the name "sequoia" generally refers to ''

Sequoiadendron giganteum ''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, California big tree, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiade ...

,'' which occurs naturally only in the various groves that exist on the western slopes of the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

of California.National Park Service Giant Sequoia Page
accessed 1 April 2011 ''S. chaneyi'' is considered the probable direct ancestor to the extant ''Sequoiadendron giganteum''.

Description

This species was found fossilized northeast to the current ''S. giganteum'' groves in the Sierra Nevada and near

Reno Reno ( ) is a city in the northwest section of the U.S. state of Nevada, along the Nevada-California border, about north from Lake Tahoe, known as "The Biggest Little City in the World". Known for its casino and tourism industry, Reno is the ...

. It was very similar to the modern species, even having the same plants associated with its fossils as the modern Sequoia.

Occurrences

Fossils of ''Sequoiadendron chaneyi'' have been described from the Middle Miocene floras found in the area of Middlegate Basin in

Churchill County, Nevada Churchill County is a county in the western U.S. state of Nevada. As of the 2020 census, the population was 25,516. Its county seat is Fallon. Named for Mexican–American War hero brevet Brigadier General Sylvester Churchill, the county was f ...

. The area of the Middlegate basin is preserved as the Middlegate and Eastgate Formations, which grew along the shores of an ancient lake. While ''S. chaneyi'' is found in both formations, it is much rarer in the Middlegate formation, which was a south-facing scrubland-type ecosystem, being represented by only a few twiglets with foliage. In contrast, ''S. chaneyi'' is abundant in the Eastgate formation, which was a north-facing forested setting of hills and valleys, being represented by abundant foliage and several cones. Specimens figured as ''

Glyptostrobus ''Glyptostrobus'' is a small genus of conifers in the family Cupressaceae (formerly in the family Taxodiaceae). The sole living species, '' Glyptostrobus pensilis'', is native to subtropical southeastern China, from Fujian west to southeast Yu ...

'' by Jack Wolfe in 1964 from the Middlegate basin were re-identified by Daniel Axelrod in 1985 as ''S. chaneyi'', based on morphology and the presence of cones in the same deposits. Fossils of ''S. chaneyi'' have been found in the late Miocene Relief Peak Formation of

Alpine County, California , other_name = , settlement_type = County , image_skyline = , image_flag = Flag of Alpine County, California.svg , flag_size = , image_seal = Seal of Alpine Co ...

. The fossils are found in the topmost section of the Relief Peak Formation at the contact of the formation and the Mount Reba Conglomerate. The stratigraphy and composition of formations indicate that the fossils of the Mount Reba flora were deposited in a low, broad valley environment that drained southwesterly and was exposed to the storm track. While present in the flora, ''S. chaneyi'' was a very rare component of it, being known from only three foliage specimens. The specimens were most likely transported downstream from the site where the trees were growing. ''S. chaneyi'' is known from the Middle Miocene Chloropagus Formation deposits of Storey County, Nevada, west of Fernley. While the fossils are locally abundant at several of the Purple Mountain flora sites, it is found as a component at most of the sites. The higher concentrations seem to be associated with those deposits which were formed in mesic bottomlands.

References

{{Taxonbar, from=Q7452558 †chaneyi Miocene plants Fossil taxa described in 1956 Flora of North America Extinct flora of North America Prehistoric trees