Pinus matthewsii

Pinus matthewsii; Temporal range: Pliocene PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Pinaceae
Genus:	Pinus
Section:	P. sect. Trifoliae
Subsection:	P. subsect. Contortae
Species:	P. matthewsii
Binomial name
	Pinus matthewsii; McKown, Stockey, & Schweger, 2002

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.^[1]

Type locality

Pinus matthewsii was described from the three

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.^[1]

History and classification

Pinus matthewsii is known from only three fossils, the

paleobotanists Athena D. McKown and Ruth A. Stockey of the University of Alberta 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.^[1] 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.^[1]

The ovulate cones of Pinus matthewsii range from 3.4–4.4 centimetres (1.3–1.7 in) in length and 2.8–3.4 centimetres (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.[1]

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 with long detachable wings. The combination of characters would support a large wind dispersal range.^[1]

References

^
S2CID 86234947. Archived from the original
(PDF) on 2008-02-21. Retrieved 2011-05-16.

[McKown2002-1] 
S2CID 86234947. Archived from the original
(PDF) on 2008-02-21. Retrieved 2011-05-16.

[1]