Spondylus bostrychites Guppy, 1867
GUPPY, R. J. L. 1867. On the Tertiary fossils of the West-Indies, with especial reference to the classification of the Kainozoic rocks of Trinidad. Scientific Association of Trinidad, Proceedings, 1 (3): 145-176 [reprinted 1921, Bulletins of American Paleontology, 35: 14-55] [p. 176]
1850 Spondylus bifrons G. B. Sowerby I, 1850
1867 Spondylus bostrychites Guppy, 1867
1887 Spondylus pinguisculus White, 1887
1867 Spondylus bostrychites Guppy, 1867
1887 Spondylus pinguisculus White, 1887
Spondylus bostrychites Guppy; H. E. Vokes & E. H. Vokes, 1992, Neogene paleontology in the northern Dominican Republic, plate 1, figures 1-3.
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«S. bifrons Sow. (non Goldfuss) Quart. Journ. Geol. Soc., vol. vi., p. 53.
A species found in Haiti and Anguilla. As the name bifrons had been already given by Goldfuss to a species of the same genus it is necessary to change the name.» ROBERT JOHN LECHMERE GUPPY, 1867
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«Description.— Shell rounded, pectiniform, subequivalved with the lower (right) valve slightly more inflated than the upper (left) one; attachment area on lower valve small or absent, marked occasionally by smalI area of raised concentric lamellae; remainder of surface of right valve and all of the left with radial ribbing consisting, on welI-preserved valves, of ribs of four different strengths: the strongest, primary ribs most prominent and bearing large, elongate flattened or fluted spines, the ribs of secondary strength with distantly spaced, nodose spinules; the tertiary riblets occurring in groups of two to four. commonly three, separating the primary and secondaries, and often relatively smooth; quaternary riblets visible only on exceptionally well-preserved valves, submicroscopic and exceedingly numerous, often being present on the sides and upper surfaces of the primary, secondary, and tertiary ribs. WelI-preserved valves also with ribbing crossed by fine raised growth lines that form small raised spinose flutings on the rib tops. Commonly seven primary ribs on the lower (right) valve and six on the upper (left) one. Cardinal area of the lower valve somewhat broader than that ofthe narrow, often linear, upper one; both coarsely striated. Auricles moderately large, with radial ribbing that may be obscured by strong, raised growth lamellae. Adductor scar gently arched to almost straight dorsally, broadly rounded on lateral and ventral sides; ventral internal valve margins crenulated by termination ofexternal radial ornament.
Lectotype.— BMNH LL 9946 (selected by Palmer, 1938). Type locality.— Locality TU 1219 (here restricted), Gurabo Formation, Rio Amina, bluffs on east side of river immediately upstream from ford that is 2 km west of Potrero and about 3 km downstream from "La Represa" (= locality USGS 8516; see Saunders, lung, and Biju-Duval, 1986, text-fig. 34). Material.— Over 100 valves, many paired; plus numerous immature and/or fragmentary specimens, from many localities, mostly in the shalIow-water facies of the Gurabo Formation. Measurements (in mm).-- Remarks.— Although there are rare specimens of S. bostrychites Guppy, 1867, from the Cercado Formation (one pair from loc. TV 1222, near Moncion) and from the Mao Adentro Member of the Mao Formation on the Rio Gurabo (Iocs. TV 1440, NMB 15822; see Saunders, lung, and Biju-Duval, 1986, text-figs. 4,5), the vast majority of the specimens have been taken in the shallow-water facies of the Gurabo Formation. In our colIections and those of the Naturhistorisches Museum, the species is most abundant along the Rio Gurabo above the ford, in beds that Maury (1917, p. 437) referred to her Zones D (Ioc. TV 1215 = NMB 1584215858; see Saunders, lung, and Biju-Duval, 1986, textfigs. 4, 5) and F (Iocs. TV 1277, 1296 = locs. NMB 15864-15875; see Saunders, lung, and Biju-Duval, 1986, text-figs. 4, 5), at "Bluff I" (of Maury, 1917, p. 426, where she noted it was "common") on the Rio Mao (Iocs. TU 1293. NMB 16910; see Saunders, lung, and Biju-Duval, 1986, text-fig. 29), and at the ford on the Río Amina (Iocs. TV 1219. NMB 16807; see Saunders, Jung, and Biju-Duval, 1986. text-fig. 34). Although the NMB team was not able to collect the latter locality to any great degree, in the TU collections from locality TU 1219 alone we have 20 adult valves (three paired) and 40 immature valves. Inasmuch as this is certainly one of the localities where the original Heneken ColIection³ was made, locality TU 1219 is here offered as a restriction of the type locality, which was
only "San Domingo". The species of Spondylus are alI discouragingly similar and one species may be distinguished from another only with great difficulty. One of the most striking characteristics exhibited by Spondylus bostrychites is the lack of an attachment area. Most species are marked by a relatively large area of concentric foliations in the umbonal area of the right valve. As may be seen from the various specimens figured, this is not usualIy developed in S. bostrychites. Of al of the specimens in the TU collections only three show any trace of this attachment area. The significance of the lack of attachment area would seem to be that, unlike the majority of spondylid species, which attach to some hard substrate - corals, rocks, etc., S. bostrychites did not affix itself to any hard surface but "floated" on a silty bottom. Waller (written communication. April 2, 1990) has suggested that the species may be an opportunistic cementer, with settling spat cementing themselves to tiny hard objects on the silty bottom when such objects may be found. The same life-style has been documented for the large oyster Hyotissa haitensis (Sowerby, 1850), which occurs together with S. bostrychites at many localities (see Meeder, 1987, p. 11). Specimens from several other formations throughout the western Atlantic have been cited as S. bostrychites. In our opinion, all of these, with the possible exception of the Puerto Rican specimens listed but not figured by Maury (1920, p. 22) and Hubbard (1920, p. 97), both of which were based on incomplete molds, prove to be other species. In particular, the examples from the Bowden Formation, Jamaica, which have been figured by Woodring (1925, pl. 9, figs. 5-7) and Palmer (1938, pl. 16, fig. 1), show the attachment area (see PI. 1. fig. 4). They are here assigned to the Recent species S. americanus Hermann, 1781.» ³ The Heneken Colleclion was sent to the Geological Society of London in 1848 and was Ihe basis for Ihe molluscan descriplions of Sowerby (1850) and Guppy (1876).
VOKES, H. E. & E. H. VOKES. 1992. Neogene paleontology in the northern Dominican Republic. 12. The genus Spondylus (Bivalvia:Spondylidae). Bulletins of American Paleontology, 102: 5-13, pls. 1-3. [p. 9, 10]
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Spondylus bostrychites Guppy; H. E. Vokes & E. H. Vokes, 1992, Neogene paleontology in the northern Dominican Republic. 12. The genus Spondylus, plate 1, figures 1-3; plates 2, figure 1.
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