Pinus matthewsii
Encyclopedia
Pinus matthewsii is an extinct
species
of conifer in the Pine
family. The species is solely known from the Pliocene
sediments exposed at Ch’ijee’s Bluff on the Porcupine River
near Old Crow, Yukon
, Canada.
specimens all found at the Ch’ijee’s Bluff locality, number HH228. This locality is in the Bluefish Basin and considered part of one of the most complete records of the Pliocene and Early Pleistocene in northwestern North America. The Bluefish and neighboring Old Crow basins were part of the unglaciated Beringian refugium of North America, which harbored the ancestors of the modern pine
subsection
Contortae. The subsection is though to have radiated out from the refugium into the species P. contorta and P. banksiana. All the cones were preserved in the basal "unit 1" section of the Ch’ijee’s Bluff outcrop. Unit 1 is composed of sands, gravels and clays, thought to have been forest floor which was rapidly covered by alluvial sediments.
, number "UAPC-ALTA P610", and the paratype
s number "UAPC-ALTA 609" and "UAPC-ALTA 611". All three specimens, plus thin section
slides are preserved in the paleobotanical
collections housed in the University of Alberta
in Edmonton, Alberta, Canada. The specimens were studied by paleobotanists Athena D. McKown and Ruth A. Stockey of the University of Albert Department of Biological Sciences, and Charles E. Schweger of the Department of Anthropology. Athena McKown and coauthors published the 2002 type description for P. matthewsii in the International Journal of Plant Sciences
. In describing the species Athena McKown and coauthors chose the specific name
matthewsii, in honor of John V. Matthews, Jr. of the Geological Survey of Canada in recognition of his work on Tertiary
and Quaternary
paleoenvironmental reconstructions, through palynology
and paleobotany
, of Alaska
and Yukon locations.
The ovulate cones of Pinus matthewsii range from 3.4–4.4 cm (1.3–1.7 in) in length and 2.8–3.4 cm (1.1–1.3 in). While the overall morphology and structure of P. matthewsii cones compare to cones of the living species Pinus banksiana, notable differences occur. The elongated cones of P. banksiana have an asymmetrically reflexed cone base, while P. matthewsii are symmetrical and oval. Cones of P. matthewsii and P. contorta are also similar in structuring, however the combination of characters that are present in P. matthewsii are not found in any one of the subspecies of P. contorta.
Similar to the modern habits of P. contorta, it is suggested that P. matthewsii may have been a shade intolerant tree which acted as a colonizer. This is supported by the seeds preserved within the cones, the seeds being small and detachable from wings
that are long. The combination of characters would support a large wind dispersal range.
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally 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 recover may have been lost before this point...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of conifer in the Pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
family. The species is solely known from the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
sediments exposed at Ch’ijee’s Bluff on the Porcupine River
Porcupine River
The Porcupine River is a river that runs through Alaska and the Yukon. Having its source in the Ogilvie Mountains north of Dawson City, Yukon, it flows north, veers to the southwest, goes through the community of Old Crow, Yukon, flowing into the Yukon River at Fort Yukon, Alaska...
near Old Crow, Yukon
Old Crow, Yukon
-Population data:-External links:******, a National Film Board of Canada documentary...
, Canada.
Type locality
Pinus matthewsii was described from the three ovulate coneConifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
specimens all found at the Ch’ijee’s Bluff locality, number HH228. This locality is in the Bluefish Basin and considered part of one of the most complete records of the Pliocene and Early Pleistocene in northwestern North America. The Bluefish and neighboring Old Crow basins were part of the unglaciated Beringian refugium of North America, which harbored the ancestors of the modern pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
subsection
Section (botany)
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections are typically used to help organise very large genera, which may have hundreds of species...
Contortae. The subsection is though to have radiated out from the refugium into the species P. contorta and P. banksiana. All the cones were preserved in the basal "unit 1" section of the Ch’ijee’s Bluff outcrop. Unit 1 is composed of sands, gravels and clays, thought to have been forest floor which was rapidly covered by alluvial sediments.
History and classification
Pinus matthewsii is known from only three fossils, the holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, number "UAPC-ALTA P610", and the paratype
Paratype
Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...
s number "UAPC-ALTA 609" and "UAPC-ALTA 611". All three specimens, plus thin section
Thin section
In optical mineralogy and petrography, a thin section is a laboratory preparation of a rock, mineral, soil, pottery, bones, or even metal sample for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a...
slides are preserved in the paleobotanical
Paleobotany
Paleobotany, also spelled as palaeobotany , is the branch of paleontology or paleobiology dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments , and both the evolutionary history of plants, with a...
collections housed in the University of Alberta
University of Alberta
The University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...
in Edmonton, Alberta, Canada. The specimens were studied by paleobotanists Athena D. McKown and Ruth A. Stockey of the University of Albert Department of Biological Sciences, and Charles E. Schweger of the Department of Anthropology. Athena McKown and coauthors published the 2002 type description for P. matthewsii in the International Journal of Plant Sciences
International Journal of Plant Sciences
The International Journal of Plant Sciences covers botanical research including genetics and genomics, developmental and cell biology, biochemistry and physiology, morphology and structure, systematics, plant-microbe interactions, paleobotany, evolution, and ecology. The journal also regularly...
. In describing the species Athena McKown and coauthors chose the specific name
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
matthewsii, in honor of John V. Matthews, Jr. of the Geological Survey of Canada in recognition of his work on Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
and Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
paleoenvironmental reconstructions, through palynology
Palynology
Palynology is the science that studies contemporary and fossil palynomorphs, including pollen, spores, orbicules, dinoflagellate cysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter and kerogen found in sedimentary rocks and sediments...
and paleobotany
Paleobotany
Paleobotany, also spelled as palaeobotany , is the branch of paleontology or paleobiology dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments , and both the evolutionary history of plants, with a...
, of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and Yukon locations.
The ovulate cones of Pinus matthewsii range from 3.4–4.4 cm (1.3–1.7 in) in length and 2.8–3.4 cm (1.1–1.3 in). While the overall morphology and structure of P. matthewsii cones compare to cones of the living species Pinus banksiana, notable differences occur. The elongated cones of P. banksiana have an asymmetrically reflexed cone base, while P. matthewsii are symmetrical and oval. Cones of P. matthewsii and P. contorta are also similar in structuring, however the combination of characters that are present in P. matthewsii are not found in any one of the subspecies of P. contorta.
Similar to the modern habits of P. contorta, it is suggested that P. matthewsii may have been a shade intolerant tree which acted as a colonizer. This is supported by the seeds preserved within the cones, the seeds being small and detachable from wings
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
that are long. The combination of characters would support a large wind dispersal range.