Nodipecten veatchii (Gabb, 1866)
GABB, W. M. 1866-1869. Paleontology of California. Vol II. Cretaceous and Tertiary fossils. Geological Survey of California, 299 p., pls. 1-36. [p. 32, pl. 10, fig. 56]
1866 Pecten veatchii Gabb, 1866
W. M. Gabb, 1866, plate 10.
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«SHELL large, equivalve, a very little broader than long; base regularly rounded; sides sloping above, with a slight concavity; ears unequal; sinus in the right ear of the lower valve moderately deep; surface of ears covered by small radiating ribs and fine imbricating lines of growth; surface of valves ornamented by about eight broad, flat, subnodose ribs, arranged in pairs, and a few small linear ribs on the side; besides the ribs, the whole surface is covered by small radiating lines, and crossed by very irregular lines of growth, and very fine imbricating concentric lines.
Figure, natural size. Locality: With the preceding [Cerros Island, off the coast of Lower California: probably Miocene. Collected by Dr. J. A. Veatch].» WILLIAM MORE GABB, 1866
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«Description. — Valves equally convex, length slightly greater than height; almost always with four or five ledges. Beaks project equally above hinge line. Auricles subequal, with seven or eight costae; byssal notch moderately deep. Hinge line equal to half shell length. Umbonal angle 96-100°. Right valves with six ribs, four strongly paired and one or two marginal riblets arranged on either side of a very wide central space. Four to five ledges common in individuals as much as 6 cm high, zero to several more in later growth stages. Ledges are rounded in right valves, angular and steplike in left valves. Left valves with 6-7 unpaired ribs that alternate between narrow and wide, the broadest rib in the central position. Wider left-valve ribs with prominent hollow nodes in the pattern r N r Nc r N r. Adults range as large as 13.5 cm high, 14.5 cm long, and 8 cm in hinge length.
Variability. — Rib counts vary with prominence of incipient marginal ribs. Development of nodes and ledges vary as in Holocene specimens of N. nodosus, N. arthriticus, and N. subnodosus. Comparative notes.— Nodipecten veatchii has the same fine lirate striate macrosculpture but a lower rib count than N. subnodosus; the latter lives today in western Baja California and in the Gulf of California. Flat, rectangular ribs and spaces are very wide in N. veatchii; right-valve ribs are strongly paired. Its characteristic Nodipecten leftvalve scheme, .. N r Nc r N.., low rib count and presence of hollow nodes distinguish it from Lyropecten gallegosi and L. modulatus which are found with it. Phylogenetic affinities.-- Nodipecten veatchii is a cognate of N. peedeensis from the Carolina coastal plain. It is morphologically closest to Nodipectens from the Gulf of Mexico and Florida, forms referred here to N. fragosus. It may represent a relict of the Tertiary Caribbean Province, although it is unknown from Panama and the Caribbean islands. Geographic distribution and stratigraphic occurrence.— Restricted to Cedros Island and the Vizcaino Peninsula, Baja California Sur, from the Almejas Formation and younger reworked deposits on Cedros Island. Not from the Saugus Formation (Kew, 1924; Woodring, 1930). Cedros Island, east coast. Northern section: from small canyon south of Arroyo Choyal, about 9 mi north of the town of Cedros (CAS 946) where it is found with Lyropecten gallegosi and L. modulatus in coarse pebble to cobble conglomerate. Southern section: abundant in conglomerate exposed in canyon south of main part of town of Cedros ("Arroyo de los Puercos," LSJU 806, CAS 928, FK-53). It occurs with Swiftopecten parmeelei, a Pliocene index species that is also in the Jacalitos Hills, Fresno County, Calif. (Stanton and Dodd, 1976). Also in Pecten-algal beds (UCMP D-795) and in the "Laqueus zone" cropping out at mouth of "Brachiopod Canyon" (Frank Kilmer, oral commun., 1973). Tertiary marine strata at Cedros Island have not been assigned a formal name, but the conglomeratic facies is probably a turbidite or channel deposit; it has many of the pectinids found in the Almejas Formation at Turtle Bay. The fossils are oriented randomly in the very coarse, loosely consolidated matrix (fig. 16). On the basis of mollusks, the northern section is considered slightly older than the southern section. Turtle Bay, Vizcaino Peninsula. North of town (CAS 27258; UCMP B-3014). The Pliocene rocks of Jordan and Hertlein (1926) are now considered to be the upper Miocene Almejas Formation (Smith, 1984). Also from Asuncion, in coarse-grained yellowish sandstones with Turritella, barnacles, and pectinid fragments (Smith field check, 1979). Geologic age.— Late Miocene to earliest Pliocene (probably reworked in the Pliocene). Biostratigraphy.— Equivalent to the upper "Margaritan" and "Jacalitos" Stages of California; age is based upon contemporaneous Lyropectens. 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. 100]
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Nodipecten veatchii (Gabb, 1866); J. T. Smith, 1991, Cenozoic Giant Pectinids from California and the Tertiary Caribbean Province, pl. 14, fig. 8; pl. 15, figs. 5, 6.
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