Acer ivanofense
| Acer ivanofense Temporal range:
| |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Sapindales |
| Family: | Sapindaceae |
| Genus: | Acer |
| Section: | Acer sect. Glabra |
| Species: | †A. ivanofense
|
| Binomial name | |
| †Acer ivanofense Wolfe & Tanai
| |
Acer ivanofense is an extinct
United States of America. It is one of several extinct species placed in the living section Glabra.[2]
History and classification
Acer ivanofense is represented by a group of fossil specimens recovered from late Eocene to early Oligocenepaleobotanists Jack A. Wolfe of the United States Geological Survey, Denver office and Toshimasa Tanai of Hokkaido University. Wolfe and Tanai published their 1987 type description for A. ivanofense in the Journal of the Faculty of Science, Hokkaido University. The etymology of the chosen specific name ivanofense is in recognition of the type location for the species in Ivanof Bay, Alaska.[2]
Description
Leaves of A. ivanofense are simple in structure with a perfectly
actinodromous vein structure in which the primary veins originate at the base of the lamina and run out towards the margin. The three-lobed leaves widely oval in shape with the lateral lobes being about one-half the width of the middle lobe. The leaves have three primary veins and an estimated size range of 4.5–7.8 centimetres (1.8–3.1 in) long by 4.0–7.5 centimetres (1.6–3.0 in).[2] Between four and seven secondary veins branch from the basal side of each lobal primary vein which then branch to form a bracing structure for the lobe. The leaves host compound teeth with each major tooth having two to three small teeth on the bottom edge and one tooth on the tip edge. The morphology of A. ivanofense suggests placement into the Acer section Glabra and the series Arguta. This is based on the overall vein structure in the lobes and the structuring of the veins forming the areolae.[2]
References
- ^ a b c d Detterman, R.L.; Case, J.E.; Miller, J.W.; Wilson, F.H.; Yount, M.E. (1996). "Stratigraphic Framework of the Alaska Peninsula" (PDF). United States Geological Survey Bulletin. 1969-A: 46–48. Archived from the original (PDF) on 2012-04-15. Retrieved 2012-12-17.
- ^ a b c d e Wolfe, J.A.; Tanai, T. (1987). "Systematics, Phylogeny, and Distribution of Acer (maples) in the Cenozoic of Western North America". Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and Mineralogy. 22 (1): 23, 74, 75, 240, & plate 4.