Lyropecten vaughani (Arnold, 1906)
ARNOLD, R. 1906. The Tertiary and Quaternary pectens of California. United States Geological Survey Professional Paper, 47: 1-264, pls. 1-53. [p. 81, pl. 23, figs. 3, 3a, 3b]
1906 Pecten (Lyropecten) vaughani Arnold, 1906
R. Arnold, 1906, plate 23.
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«Description.— Shell averaging about 40 millimeters in altitude, slightly longer than high, inequivalve, equilateral, convex, and showing constrictions with consequent undulations on the right valve and nodose ribs on the left; base regularly rounded; sides nearly straight above; margins smooth. Right valve with 12 prominent convex ribs separated by concave-bottomed interspaces somewhat narrower than the ribs; surface of ribs and interspaces sculptured by numerous fine, imbricated, thread-like, radial lines, between which are fine imbricating concentric lirae, the lines multiplying by intercalation toward the periphery of the disk; hinge line about five-eighths length of disk; ears unequal, the anterior much elongated, rather narrow, and ornamented by 4 very prominent, rounded, sharply imbricated radials and numerous fine imbricating incremental lirae; byssal notch deep; posterior ear about one-half length of anterior, somewhat concave behind, and ornamented by about 6 radial and numerous fine incremental lirae. Left valve similar to right, but with narrower, sharper ribs and correspondingly broader interspaces; the second, fourth, seventh, tenth, and twelfth ribs from the posterior end are more prominent than the others, and are subnodose at the lines of undulation of the disk; anterior ear similar to that of the right valve but with 2 or 3 more radials, which are less prominent; posterior ear like that of right.
Dimensions.— Alt. 37 mm.; long. 10 mm.: hinge line about 2.5 mm.; diameter 15 mm. This beautiful little Pecten though allied to P. magnolia, P. crassicardo, etc.. is distinguishable by its small size, obviously unequal ears, long and strongly radially sculptured right anterior ear, deep byssal notch, undulating disk, and finely striated, concave-bottomed interspaces. This form seems to combine the number of ribs of P. magnolia (P. magnolia generally has one to three less), with the sculpture of P. crassicardo var. hamiltoni, the undulations of P. crassicardo, and the long, strongly sculptured, right anterior ear of the typical Chlamys. It appears to be a connecting link between the typical Chlamys and Lyropecten. The range of this species is not definitely known. It is found in the Miocene, probably lower, of the Ojai Valley. Ventura County. The type, which was collected at the above locality by Dr. Stephen Bowers, is now in the collection of Delos Arnold. The species is named in honor of Dr. T. Wayland Vaughan, of the United States Geological Survey. RANGE
Miocene (lower). Ojai Valley, Ventura County (Bowers).»
RALPH ARNOLD, 1906
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«Description. — The type specimen has equally convex valves, a single constriction or incipient ledge, and beaks that project equally, slightly, above the hinge line. Auricles unequal, costate, lirate. Byssal notch deep. Hinge length greater than half the shell length. Right valve has 11 ribs, left valve 11 ribs with incipient nodes on every third rib. Rib scheme is N 2r Nc 2r N. Fine macrosculpture not preserved.
Phylogenetic affinities. — The holotype belongs with the L. crassicardo-L. magnificus stock on the basis of leftvalve key-rib scheme. It is possibly the same as L. pretiosus (= L. submiguelensis authors), which it resembles in growth form and ribbing.» SMITH, J. T. 1991. Cenozoic Giant Pectinids from California and the Tertiary Caribbean Province: Lyropecten, "Macrochlamis", Vertipecten, and Nodipecten species. United States Geological Survey Professional Paper, 1391: v + 1-155, figs. 1-18, pls. 1-38. [p. 69]
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Lyropecten vaughani (Arnold, 1906); J. T. Smith, 1991, Cenozoic Giant Pectinids from California and the Tertiary Caribbean Province, plate 26, figures 10, 11.
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«The "few-ribbed Ojai form" can be separated morphologically and stratigraphically from "M." magnolia, s.s. Pecten emigdioensis Wagner and Schilling, based on a juvenile left valve from the San Emigdio Range, is possibly a juvenile of this taxon, although the name is rejected because it is not certain that the single immature specimen is the same species as the abundant adult "machrochlamids" in the Ojai Valley.»
SMITH, J. T. 1991. Cenozoic Giant Pectinids from California and the Tertiary Caribbean Province: Lyropecten, "Macrochlamis", Vertipecten, and Nodipecten species. United States Geological Survey Professional Paper, 1391: v + 1-155, figs. 1-18, pls. 1-38. [p. 74]
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«Pecten vaughani Arnold has not been found positively outside the type vicinity in Ojai Valley on the pass to upper Ojai Valley, Ventura County. It is there associated with P. magnolia and P. sespeensis, Vaqueros Lower Miocene. Poorly preserved specimens not definitely determinable were collected in the Bryson-Bradley region.
After consideration of the one left valve of Pecten (Lyrpecten) vaughani var. emigdioensis Wagner and Schilling it is here referred to P. vaughani Arnold. The fauna, with which it is associated is Vaqueros, Lower Miocene.» LOEL, W. & W. H. COREY. 1932. The Vaqueros formation, lower Miocene of California I. Paleontology. University of California Publications, Bulletin of the Department of Geological Sciences, 22 (3): 31-410, pls. 4-65. [p. 201, 202]
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Pecten (Lyropecten) vaughani Arnold; W. Loel & W. H. Corey, 1932, The Vaqueros formation, lower Miocene of California I. Paleontology, plate 21, figure 9.
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