Argopecten deserti (Conrad, 1855)
CONRAD, T. A. 1855. Report of Mr. T. A. Conrad on the fossil shells collected in California by W.P. Blake, geologist of the expedition, under the command of Lieutenant R.S. Williamson, United States Topographical Engeneers, 1853. In William P. Blake (1855): Description of the fossils and shells collected in California by William P. Blake. Appendix to the preliminary geological report. Washington, 1855: 5-21. [p. 15]
1855 Pecten deserti Conrad, 1855
Pecten deserti Con.; T. A. Conrad, 1856, Appendix of Geological Report by William P. Blake, Descriptions of the Fossil Shells, plate 5, figure 41.
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«Suborbicular, both valves convex; ribs about 23, rounded, somewhat flattened toward the base, about as wide as the interstices; in the lower valve much wider than the interstices, and the valve more convex than the opposite one; ears equal in the upper valve; left ear of lower valve extended downwards and very obliquely striated; cartilage pit profound; a submarginal channel parallel with the upper margin.
Locality. — Carrizo creek, Colorado desert. Miocene.» TIMOTHY ABBOT CONRAD, 1855
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«Argopecten invalidus is similar to A. deserti (Conrad, 1855) and the extant A. ventricosus (G.B. Sowerby II, 1842). Argopecten invalidus differs from A. deserti by having larger size, right-valve interspaces narrower than the ribs, left-valve ribs narrower than those on the right valve, left-valve interspaces wider than the ribs, more ribs on the right-valve anterior auricle, and a shorter hinge line.»
SQUIRES, R. L. 2012. Late Pliocene Megafossils of the Pico Formation, Newhall area, Los Angeles County, Southern California. Los Angeles County Museum Contributions in Science, 520: 73-93, figs. 1-108. [p. 81]
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«This species was originally described from specimens collected in the region by Blake and, being common, is very well known. The various collections studied have contained a great many specimens of it. The species is most common in the hard "oyster reefs" of the uppermost beds exposed. Some places these beds are consolidated into firm rock; again they have disintegrated and the desert floor then becomes carpeted with the shells of Pecten deserti, Ostrea vespertina and Anomia subcostata. They thus become scattered far and wide.»
HANNA, G. D. 1926. Paleontology of Coyote Mountain, Imperial County, California. Proceedings of the California Academy of Sciences [4th Series], 14 (18): 427-503, text fig. 1, pls. 20-29. [p. 470, 471]
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Pecten deserti Conrad; G. D. Hanna, 1926, Paleontology of Coyote Mountain, plate 25, figures 1-3.
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«Notes.— Some of the specimens of this species from the Kettleman Hills (locality 4715) are indistinguishable from individuals from the type locality on Carrizo Creek, San Diego County. The Kettleman Hill specimens vary in size considerably, the largest one in hand attaining an altitude of over 50 millimeters. A prominent characteristic which is developed in some of the Carrizo Creek shells, but is more common in the Kettleman Hills individuals, is the occurrence of one to three radiating lines or riblets in the bottom of each interspace or on the lower portions of the ribs in the later stages of growth. There is also a noticeable tendency for the disks to become contracted or show lines of interrupted growth from a diameter of about 25 millimeters upward.
Figured specimens.— Catalogue No. 165518, U.S.N.M., from locality 4715. Localities.— In the Etchegoin formation, upper Miocene, Coalinga district, at United States Geological Survey locality 4712, east of Zapato Creek, three-fourths mile south-southwest of A. Kreyenhagen's house, SW. ¼ SE. ¼ sec. 8, T. 22 S., R. 16 E. (Fresno County); locality 4715, south end of Kettleman Hills, sec. 10, T. 25 S., R. 19 E. (Kings County). In the Carrizo Creek beds, upper Miocene, San Diego County, at east end of Carrizo Mountain, and at Ulsa oil well, north of the Mexican boundary (Conrad; H. W. Fairbanks; S. Bowers; W. C. Mendenhall). Horizon.— Upper Miocene.» ARNOLD, R. 1910. Paleontology of Coalinga district, Fresno and Kings Counties, California. United States Geological Survey Bulletin, 396: 1-173, pls. 1-30. [p. 76, 77]
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Pecten (Plagioctenium) deserti Conrad; R. Arnold, 1910, Paleontology of Coalinga district, Fresno and Kings Counties, California, plate 26, figures 3, 4.
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