| Eosalmo Temporal range:
[1]
| |
|---|---|
| |
| Eosalmo driftwoodensis, Klondike Mountain Formation, Washington, USA | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Salmoniformes |
| Family: | Salmonidae |
| Subfamily: | Salmoninae |
| Genus: | †
Eosalmo Wilson, 1977 |
| Species: | †E. driftwoodensis
|
| Binomial name | |
| †Eosalmo driftwoodensis
Wilson, 1977
| |
Eosalmo is an extinct genus of ancient salmonid that lived during the Eocene epoch. [1]
The genus was first described in 1977 from fossils found in lacustrine deposits in Driftwood Canyon Provincial Park, near Smithers, British Columbia, Canada, leading to the specific epithet E. driftwoodensis. [2] Fossils from this genus have also been found at sites in Princeton, British Columbia, the McAbee Fossil Beds in B.C., and Republic, Washington, United States. [3]
When first described the genus was thought to be intermediate in form to the extant salmonid subfamilies Salmoninae ( trout and salmon) and Thymallinae ( graylings). More recent review of the genus has placed Eosalmo as the most primitive member of the Salmoninae subfamily. [3] Fossils found in Driftwood Canyon Provincial Park display a full range of individuals from young juveniles through adults. This range indicates that the genus was completely freshwater dwelling and did not spend time in saltwater. [4]
Morphology
Several unique characters found in Eosalmo separate the genus from extant salmonids. The subopercle exhibits an anetrodorsal process which meets the edge of the subopercle at approximately a 60° angle. [3] Also unique is the basihyal tooth plate, which is broad, flat, thin, and lacking any teeth along the edges. Modern salmonids possess stout teeth along the edge of the basihyal. [3] The morphology suggests Eosalmo represents an intermediate between the modern Salmoninae and Thymallinae subfamilies and evolved from a grayling like ancestor. [5]
See also
References
- ^ a b Sepkoski, J (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Archived from the original on 2011-07-23. Retrieved 2009-02-27.
- ^ Wilson, MVH (1977). "Middle Eocene freshwater fishes from British Columbia". Life Sciences Contributions, Royal Ontario Museum. 113: 1–66.
- ^ a b c d Wilson, MVH; Li, Guo-Qing (1999). "Osteology and systematic position of the Eocene salmonid †Eosalmo driftwoodensis Wilson from western North America" (PDF). Zoological Journal of the Linnean Society. 99 (125): 279–311. doi: 10.1111/j.1096-3642.1999.tb00594.x. Retrieved 2010-01-01.
- ^ "Burke Museum Eosalmo page". Archived from the original on 2011-06-04. Retrieved 2010-01-13.
- ^ "Geological Survey of Canada". nrcan.gc.ca. Archived from the original on 21 December 2009. Retrieved 11 April 2018.
 | This article about a prehistoric ray-finned fish is a stub. You can help Wikipedia by expanding it. |
 | This Salmonidae article is a stub. You can help Wikipedia by expanding it. |