Vertipecten grunskyi (Hertlein, 1929)
HERTLEIN, L. G. 1929. Three New Specific Names for West American Fossil Mollusca. Journal of Paleontology, 3 (3): 295-297. [p.
1929 Pecten (Chamys) grunskyi Hertlein, 1929
Pecten branneri Arnold, a young individual; R. E. Dickerson, 1917, Climate and its influence upon the Oligocene faunas of the Pacific Coast, with descriptions of some new species from the Molopophorus lincolnensis Zone, plate 29, figure 2.
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«1917. Pecten branneri ARNOLD, DICKERSON, Proc. Calif. Acad. Sci.; Fourth Series, vol. 7, no. 6, July 30, 1917, p. 160, pl. 28, fig. 2. "On the east bank of the Cowlitz River just back of the Greeco ranch house, about four miles east of Vader, Washington", Lower Oligocene according to Dickerson. Not Pecten (Chlamys) branneri ARNOLD, U. S. Geol. Survey, Prof. Paper 47, 1906, p. 55, pl. 3, figs. 9, 10 and 11, "Tuff Hill, near Stanford University", Lower Miocene.
Shell rather small, higher than long, equilateral, thin flattish; sides straight, base rounded; surface ornamented by 35 to 40 fine, low, rounded ribs, separated from each other by slightly wider interspaces, some of the ribs occur in pairs which on the umbo form a single rib; a few fine midribs are present but these disappear in the earlier part of the shell; a fine tessalate sculpture is present on unweathered portions of the interspaces and ribs, otherwise the surface of the shell is ornamented only by very fine imbricating lines of growth. Anterior ear large with a deep byssal notch, ctenolium present on margin of shell near ear, about 6 to 8 radial ribs crossed by imbricating lines of growth ornament the anterior ear; posterior ear ornamented by about 6 to 8 subequal radial ribs which are crossed by concentric lines of growth. Altitude of right valve 24 mm.; longitude (approximately) 22 mm.; thickness (approximately) 1 mm.; apical angle about 90?.
Holotype.— Right valve, No. 424, Calif. Acad. Sci. Coll., from Loc. 181 (C. A. S.), on the east bank of the Cowlitz River just back of the Greeco ranch house, about four miles east of Vader, Washington; Frank M. Anderson and Bruce Martin, collectors; "Lower Oligocene", possibly upper Eocene. This species is smaller, and possesses more numerous, low, rounded ribs which lack the spiny sculpture found on Pecten (Chlamys) branneri Arnold. Pecten (Chlamys) landesi Arnold⁴ is more circular in outline, more ventricose, and the apical angle is much greater than is the case in the present species. In a report dealing with the fossil Mollusca found at Loc. 181 (C. A. S.) on the Cowlitz River, Washington, Dickerson listed and figured a species as Pecten branneri Arnold. A study of that specimen indicates that it cannot be referred to Arnold's species and it is accordingly described as Pecten (Chlamys) grunskyi in honor of Dr. C. E. Grunsky, President of the California Academy of Sciences.» ⁴ U. S. Geol, Survey, Prof. Paper 47, 1906, p. 51, pl. 2, figs. 3, 4 and 5. "Vicinity of Little Falls, Lewis County, Wash." Eocene.
LEO GEORGE HERTLEIN, 1929
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«Chlamys grunskyi (Hertlein) (new name for Pecten branneri, Dickerson, 1917, pl. 28, fig. 2), from the Gries Ranch Formation (early Oligocene), near Vader, Wash., is closely related to Vertipecten and may actually be a Vertipecten. Only the right valve of this species has been found. C. grunskyi is one of the closest known relatives of V. lachenbruchi here described, from middle Oligocene beds of Alaska.»
MACNEIL, F. S. 1967. Cenozoic pectinids of Alaska, Iceland, and other nothern regions. United States Geological Survey Professional Paper, 553: iv + 1-57, pls. 1-25. [p. 38]
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«This species has been confused with Pecten branneri Arnold; the status of the latter has been discussed by Loel and Corey (1932, pp. 196, 197), who believe it synonymous with P. sespeensis Arnold. P. grunskyi rather closely resembles P. cowlitzensis Weaver (1912, pp. 30, 31, pl. 5, fig. 46), from the Cowlitz formation near Vader, Wash.; however, comparative material was not available. The figure would suggest that P. cowlitzensis is more rounded in outline and possesses fewer ribs. Several poorly preserved specimens of Pecten are represented in the Hannibal collection from the lower Oligocene coarse sandstones of the northern Olympic Peninsula. Although the material is largely fragmentary or in the form of casts, the shape and ribbing closely resemble those of P. grunskyi.»
EFFINGER, W. L. 1938. The Gries Ranch Fauna (Oligocene) of Western Washington. Journal of Paleontology, 12 (4): 355-390, pl. 45-47. [p. 368]
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