''Corylus johnsonii'' is an
extinct species
In biology, a species is the basic unit of Taxonomy (biology), 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 ...
of
hazel
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999 ...
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 ...
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...
s found in the
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 Washingto ...
, dated to 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'', " ...
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 i ...
stage (). Based on described features, ''C. johnsonii'' is the oldest definite species in the genus ''Corylus''.
Distribution and paleoenvironment
The description of this 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 ...
s Kathleen Pigg, Steven Manchester, and Wesley Wehr was based on the study of thirty-four
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 ...
specimens found at the
UWBM sites B4131 and A0307, the latter being designated the
type locality
Type locality may refer to:
* Type locality (biology)
* Type locality (geology)
See also
* Local (disambiguation)
* Locality (disambiguation)
{{disambiguation ...
. The specimens are twelve
infructescence Infructescence (fruiting head) is defined as the ensemble of fruits derived from the ovaries of an inflorescence. It usually retains the size and structure of the inflorescence.
In some cases, infructescences are similar in appearance to simple fr ...
s with attached
involucres containing
nuts
Nut often refers to:
* Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds
* Nut (hardware), fastener used with a bolt
Nut or Nuts may also refer to:
Arts, entertainment, and media Com ...
or nut casts, fourteen involucres, and eight isolated paired or single nuts. 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 seve ...
specimen is number "SR 98-01-02 A&B", an infructescence with involucre, and is housed in the
Stonerose Interpretive Center
The Stonerose Interpretive center & Eocene Fossil Site is a 501c(3) non-profit public museum and fossil dig located in Republic, Washington. The center was established in 1989 and houses fossils that have been featured in ''National Geographic ...
in
Republic, Washington
Republic is a city in Ferry County, Washington, United States. The population was 1,073 at the 2010 census, a 12.5% increase over the 2000 census. It is the county seat of Ferry County. It was the largest mining camp in the Republic Mining Di ...
.
[ The species epithet ''johnsonii'' was coined in honor of Kirk R. Johnson for his continuing work on, and recognition of the importance of, the Republic Flora.]
Taxonomy
Though described as a single species, Pigg ''et al'' noted the wide grade of variation in the involucre morphology, ranging from simple to ones with extensive spines. The involucres also show a spectrum from thin, leafy lobes that display distinct veins to thick lobes with no distinct venation. As specimens of ''C johnsonii'' have a full morphology range between the three involucre types, the possibility of multiple species is hard to prove or disprove. However the authors chose to name a single species because of the continuous gradation present between the distinct morphologies.[
Of the two sections into which the genus ''Corylus'' is divided, section ''Corylus'' and section ''Acanthochlamys'', ''C. johnsonii'' is most similar to three species in the latter. Section ''Acanthochlamys'' is considered basal within the genus and the three species, '' Corylus ferox'', '' C.wangii'', and '' C. heterophylla'' are all native to southeast Asia. Infructescences of ''Corylus wangii'', like those of ''C. johnsonii'', possess narrow lobes with many unbranched and branched spines, while ''C. ferox''-like infructescences have a highly spiny, prickly surface. Specimens within the simple end of the infructescence morphologic range are most similar to ''C. heterophylla''. As ''C. johnsonii'' encompasses a wide morphology range within its features, it is possible it may have diverged out into the modern species. The modern areas of distribution for ''C.ferox'' and ''C. heterophylla'' overlap in the ]Sichuan province
Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of th ...
of China, while ''C. wangii'' has a distinct and separate range in southwest China.[
Isolated nuts from ]Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...
sediments in Greenland, England, and Montana have been attributed to the genus ''Corylus''. However all lack the surrounding infructescence that is needed to confirm placement of the nuts in a specific coryloid genus.[
]
Description
The infructescences bear between 2 and 3 nuts at the end of a stout stalk
Stalk or stalking may refer to:
Behaviour
* Stalk, the stealthy approach (phase) of a predator towards its prey
* Stalking, an act of intrusive behaviour or unwanted attention towards a person
* Deer stalking, the pursuit of deer for sport
Biol ...
. The nuts, in diameter, are ovoid
An oval () is a closed curve in a plane which resembles the outline of an egg. The term is not very specific, but in some areas (projective geometry, technical drawing, etc.) it is given a more precise definition, which may include either one o ...
to almost circular in outline and enclosed in an involucre composed of 2 bracts. While most specimens consist of paired involucres with ovoid nuts or nut casts, several paired or isolated nuts are known. On the nuts themselves basal attachment scars cover a small area of nut; distal scars and style
Style is a manner of doing or presenting things and may refer to:
* Architectural style, the features that make a building or structure historically identifiable
* Design, the process of creating something
* Fashion, a prevailing mode of clothing ...
remains are preserved in several specimens. A predominant number of the fruits possess more dissected involucres, some having simple spines, while others have both simple and branched spines.[
]
References
{{Taxonbar, from=Q5173725
†johnsonii
Prehistoric angiosperms
Plants described in 2003
Ypresian plants of North America
Extinct flora of North America
Klondike Mountain Formation