Conus (Lithoconus) sauridens |
(Conrad, 1833) |
(Conrad, 1865) |
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(Isaac Lea, 1833) |
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(Hoerle, 1976) |
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(De Gregorio, 1890) |
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(Gardner, 1945) |
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(Sowerby I, 1850) |
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(Garvie, 1996) |
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(Gardner, 1945) |
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(Brown & Pilsbry, 1911) |
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(Harris, 1895) |
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Conus jacksonensis |
(Meyer, 1885) |
About Palmer (11), “After an examination of a large number of specimens of the stock of Conus sauridens from the lower Claiborne, Gosport sand, Jackson and Vicksburg localities with a tabulation of the characters of the shell, a consistent character is not found which can be limited to a group of the specimens which have different names. From the lower Claiborne, Conrad named C. subsauridens but the difference in form is not constant enough to warrant separation by name.”
Conus (Lithoconus) sauridens (Conrad, 1833)
Descrizione e caratteristiche:
Conchiglia liscia ad eccezione della base, che è striata obliquamente; la superficie delle spire è appiattita e rigata; l'apice è appuntito, l'apertura è sottile e la spalla è angolata.
Il guscio è sottile e fragile, liscio con striature spirali impresse alla base; il profilo dell'ultimo giro è lineare, la spira è corta, leggermente concava, con 5/6 strie spirali e linee di accrescimento che formato un reticolo; la sutura è carenata; la spalla è angolata; la columella è piegata alla base (2).
E’ interessante il confronto del Conus sauridens con il Conus chiraensis del Perù.
v. Conus mutilatus (Alabama)
CONFRONTO: TEXAS - PANAMA – SANTO DOMINGO
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FORMA GIOVANILE
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Diagnosis: Shell large, thin, tapering, low spire and angulated shoulder. Adult specimens consisting of ten teleoconch whorls, plus three slender, nuclear whorls. Tubercles and spiral threading beginning simultaneously on first post-nuclear whorl, tubercles continuing for about seven whorls, spiral lineation constant and moderately strong. Close-set arcuate growth lines cutting, at times roughening, the spiral lineation. Sutures distinct, lightly ad pressed. Anal fasciole concave; anal notch deep; outer lip arched forward. Widely spaced incised lines encircling medial portion of last whorl, ornament gradually changing to crowded, wavy, unevenly-spaced, flattened cords around base. Aperture narrow with a slight flare anteriorly; no siphonal notch (13). Dimensions of holotype: height 37.8 mm, diameter 20.0 mm. Type locality (13): TU 655, Ten Mile Cree.k, about 0.1 mile downstream from bridge of Flonda Highway 73 (NW ~ Sec. 29, T1N, R9W), Calhoun County, Florida. Occurrence: Chipola Formation, Florida; late lower Miocene. Figured specimens (13): Fig. 1, USNM. 220109 (holotype). Fig. 3, USNM 220111; height 19.4 mm, diameter 10.5 mm; locality TU 546. Fig. 2, USNM 220110; height 52.1 mm, diameter 28.3 mm; Locality TU 830. Other occurrences: TU locality nos. 70, 196, 456, 457, 459, 554, 787, 817a, 820b, 82 5, 826,9 51 , 999, 1050, 1098. Discussion (13): C. cracens, although not common at any one locality, is well represented throughout the Chipola Formation and attains a greater size ( 60 to 7 0 mm) than other members of the group. One specimen in the Tulane University collection (TU 4 58) measures 87.8 mm in height and 52.5 mm in diameter. In this gerontic stage the rim disappears and the shoulder becomes rounded, the base is less constricted and the entire appearance is one of massiveness. C. cracens appears to be a descendant of the widespread (Alabama, Mississippi, Texas) middle Eocene to Oligocene species, C. sauridens Conrad. The development of the early post-nuclear whorls is identical in the the two species, as is also true of the anal fasciole, the forward arch of the outer lip and the rimmed shoulder. Although the two species have a number of characteristics in common, there are consistent differences, justifying the new specific name for the Chipola form. The nodes on the spire whorls persist for a greater number of turns on C. cracens, also it is larger, more slender, with stronger and more opisthocyrt growth lines and more pronounced basal ornament. C. stenostoma Sowerby reported from the (?) middle Miocene of Santo Domingo and Costa Rica and the ( ?) upper Miocene of Bowden, Jamaica and Springvale, Trinidad, possibly is derived from the Chipola species C. cracens. The affinity is shown by the three-whorled nucleus, the tuberculation of the first three to five post-nuclear whorls, the spiral lineation, the concave fasciole, the rimmed shoulders and arched outer lip. However, the sutures of C. stenostoma are more closely adpressed and the shell is consistently more attenuated anteriorly with less crowded basal ornament. Under ultraviolet light this species displays a different color pattern (broken spiral lines plus two solid spiral bands) in contrast to only broken spiral lines observed on C. cracens. Cracens, Latin for "slender "," grace ful ", was selected as an appropriate description of this species.
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Shell small or medium-size; in porportions the height approximately twice the diameter; the spire is flat to slightly elevated or conic; shells with a flat spire, have a higher, projecting tip, formed of the nuclear and early post-nuclear whorls; in the higher spired forms, the outline of the spire is low, conic with a higher, projecting nuclear tip; sides of last whorl straight; shoulder of the body-whorl is sharply angled, below which the upper face of the whorl is usually feebly rounded or beveled; post-nuclear whorls about 8, with concave spire faces, lying between the high, ridge-like, peripheral edge of the whorl and the inner sutures; this concave zone sculptured with about 4 low, broad spirals and finer transverse (radial) lines; surface of the whorl below the shoulder is smooth, polished except for growth lines and feeble, irregular spirals on the anterior canal, the growth lines are straight below, curving above to the right and deeply retracted at the shoulder; anterior canal with 12 or more feeble, irregular spiral threads; aperture long, narrow.
Remarks.
The distinguishing characteristics of this Cone
are
the straight smooth sides, feebly sculptured with revolving
spirals about the anterior canal; the spirally-sculptured spire
whorls; and strong'y retracted growth lines at the sharp shoulder
angle. The
flat spired shells illustrated by figure 2 is selected as the
typical form.
This
is the dominant form in the older beds
first
appearing in the basal Talara of Yasila and Cunas de Jaquey near
Paita. The
higher spired form illustrated by figure 1 is the common
Oligocene
variety,
but all gradations occur between it and the flat-spired
form.
Locality and Geological Occurrence. Talara formation, Yasila and Jaquey de Cunas. Saman formation, Lagunitas, Casa Saman. Chira formation, near Casa Saman, Quercotilla. Mancora formation, Que. Charanal. |
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In molti esemplari la carena è arrotondata e conferisce al profilo dell’ultimo giro un andamento sinusoidale(4). Nell’olotipo, sulle rampe non sono molto marcate(4). Nel gruppo del Conus sauridens possono essere distinte altre tre specie, oltre al Conus nocens(4): C. alveatus, C. cracens, C. tortilis. Appartengono al gruppo del Conus sauridens anche il Conus postalveatus, il Conus santander e il Conus haighti.
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Conus (Lithoconus) subsauridens (Conrad, 1865)
Descrizione
e caratteristiche:
Conchiglia allungata e conica in modo acuto, ha fianchi rettilinei, leggermente incurvati verso la sommità dell’ultimo giro; la sommità e le spire sono carenate con un angolo acuto. Differisce dal Conus alveatus per la forma; la parte inferiore ha linee più fini, più uguali e più numerose Pl. 11 fig. 9 (3).
Il Conus subsauridens non sembra essere differente dal Conus sauridens (1).
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Conus (Lithoconus) claibornensis (Isaac Lea, 1833)
Description. A small cone, for which I had proposed this name, was found in the sand, and by accident was mislaid, before the description and figure were made. It was about one quarter of an inch long, flattened on the sides, carinate above, and canaliculate on the superior part of the whorls; the spire was rather low and pointed. It is to be regretted that any accident should have happened to it, as it is the only specimen of a cone found at this locality, to my knowledge (6).
Il Conus claibornensis è un sinonimo del C. sauridens: l’esemplare ANSP 5931 è andato perso prima di essere raffigurato e descritto dettagliatamente. Conrad l’ha rapportato al Conus sauridens.
Conus (Leptoconus) smithvillensis (Harris, 1895)
Specific
characterization. —General form as figured; whorls about 12;
smaller spiral whorls costate or crenulate; penultimate whorl smooth;
body whorl smooth, except about 12 revolving lines at base.
This species bears much resemblance to the figure given in Proce. Ac.
Nat. Sci’ Phila., 1879, pl. 13, fig. 8, of “ Conus”
pulcherrimus Heilp.,
but upon examining the type of this species now in the Amer. Mus.
Nat. Hist., N. Y. City, it was found to be, as already stated by
Meyer, a Pleurotomoid shell. C.
parvus
of
H. C. Lea is evidently the young of C.
sauridens
(7)n.
1895. Conus smithvillensis HARRIS, Acad. Nat. Sci. Philadelphia, Proc., p. 55, pl. 4, fig. 2.
1937. Conus (Lithoconus) smithvillensis Harris. PALMER, Bull. Am. Paleontology, vol. 7, no. 32, p. 464, pl. 73, figs. 17, 21.
"General form as figured; whorls about 12; smaller spiral whorls costate or crenulate; penultimate whorl smooth; body whorl smooth, except about 12 revolving lines at base... (7)
"Locality. Smithville, Bastrop Co., Тех (7).
"Type. Texas State Museum." Harris, 1895 (7).
Conus smithvillensis differs from C. santander in the notably higher spire and more slender and more attenuated body. A peripheral noding is evident on the early whorls, and there is in addition a noding of the 3 or 4 moderately strong lirations on the shoulder. In our collections, none of the examples of C. smithvillensis exceed 40 millimeters in height, and the species occupies consistently a slightly lower horizon in the lower Claiborne than that in which Conus santander is found (7).
A smallish, high-spired species in the lower Laredo at U.S.G.S. sta. 13596 (H-15) near China, Carlos Cantú, Nuevo León, is commonly represented, but none of the material is well preserved. How-ever, the small size, high spire, and the few remnants of a noded sculpture pattern indicate the Smithville form. Nothing of the sort has been found in the higher horizons (7).
Distribuzione: Mississippi, Texas, Messico (7).
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Conus (Leptoconus) haighti (Gardner, 1945)
Shell rather large and heavy for the subgenus, probably as many as 15 whorls in the fully adult. Early whorls coiled in a plane that is nearly horizontal, the later whorls terraced so that in the holotype the aperture is about four fifths of the length of the shell. Sides of body converging at an angle between 35° and 40°. Protoconch not preserved in any of the available material. Earliest conchal turns high, increasing slowly in diameter and forming with the protoconch a small knob in the middle of the adolescent whorls, which are coiled in nearly a single plane. Change in the plane of coiling rather abrupt, the suture dropping in front of the narrow shoulder and giving to the spire a turreted contour. Spiral sculpture confined to a few rather feeble and irregular lirations on the shoulder, least feeble directly behind the slightly raised outer rim. Aperture oblique to the axis, narrow; the margins parallel as far as the anterior fasciole. Growth lines strongly retractive on the shoulder, bending sharply directly behind the periphery; in front of the periphery, strongly protractive. Outer lip thin, sharp, widely flaring. Inner wall apparently free from wash. Characters of anterior extremity obscured by the matrix. Anterior fasciole bulging slightly and corrugated by the heavy growth lines. No visible inner pad of callus, such as that developed in Conus santander; possibly concealed by matrix.
DIMENSIONS OF HOLOTYPE: Height, 60 millimeters; greatest diameter, 31.5 millimeters.
HOLOTYPE: U. S. Nat. Mus. 495182; incomplete paratype, U. S. Nat. Mus. 495183; figured specimen, U. S. Nat. Mus. 496037. Middle part of the Laredo formation.
TYPE LOCALITIES: Holotype, U.S.G.S. sta. 13168, Arroyo Veleño, below highway bridge on Zapata-Roma road, Zapata County, Texas; incomplete paratype, U.S.G.S. sta. 13984 (H-6); figured specimen, U.S.G.S. sta. 13565 (H-12).
Conus haighti when adult and fairly well preserved is readily separable from the earlier Conus santander. The spire is higher and more unevenly coiled. In the adolescent, the suture follows the almost horizontal shoulder so that the visible portion forms a disk with a central knob of the nuclear and earliest postnuclear whorls, and together they top the later turreted whorls like a coolie hat. The greater number of the individuals are known only from the worn posterior half of the shell, and the characters of the anterior extremity are to a certain degree conjectural. The paratype is typical of the common state of preservation. Conus haighti seems to occupy a horizon slightly higher than that in which Conus santander is abundant.
The species is named in honor of Harold W. Haight to whom we owe many of our most valuable collections.
DISTRIBUTION: Laredo formation: middle Laredo, U.S.G.S. sta. 13984 (H-6); U.S.G.S. sta. 13800 (H-9); U.S.G.S. sta. 13685 (H-9); ?U.S.G.S. sta. 13567 (H-11); U.S.G.S. sta. 13565 (H-12); U.S.G.S. sta. 13569 (H-12); U.S.G.S. sta. 13570 (H-12); U.S.G.S. sta. 13590 (I-13); U.S.G.S. sta. 13594 (H-13); U.S.G.S. sta. 13591 (H-13); U.S.G.S. sta. 13555 (H-14); U.S.G.S. sta. 13547 (I-14); U.S.G.S. sta. 13554 (I-14); U.S.G.S. sta. 13553 (H-15); U.S.G.S. sta. 13551 (H-15); U.S.G.S. sta. 13643 (M-25).
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Conus (Leptoconus) santander (Gardner, 1945)
1931. Conus sauridens Conrad. RENICK AND STENZEL, Univ. Texas Bull. 3101, p. 100, pl. 6, fig. 6. Not Conus sauridens CONRAD, Fossil shells of the Tertiary formations of North America, p. 33, 1833.
1937. Conus (Lithoconus) sauridens Conrad (part). PALMER, Bull. Am. Paleontology, vol. 7, no. 32, pp. 458-459.
Shell rather heavy, porcellaneous, the spire low and the sides converging at an angle of 45° or less. Nuclear turns small, high, smooth, and polished, 3 or 2 and a fraction in number. The 4 or 5 succeed-ing turns closely noded, the nodes on the earliest postnuclear turns medial but pushed forward with the development of the shoulder and gradually dying out. Suture following close on the shoulder on the adolescent whorls but inclined to drop farther and farther forward in the adult and gerontic forms. Spiral sculpture restricted to half a dozen or fewer not very regular spirals on the shoulder and a faint irregular lineation toward the base of the body. Aperture as wide as the shoulder, oblique to the axis of the shell, the margins parallel as far as the anterior fasciole. Anal fasciolar notch shallow as indicated by the feebly arcuate growth lines. Outer lip thin, sharp, flaring widely,
Le pareti sono nettamente più diritte rispetto al Conus sauridens.
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Conus concavitectum (Brown & Pilsbry, 1911)
A cone about twice as long as wide. Spire very concavely conic or mucronate, the inner whorls forming a very steep, acute cone, its whorls carinate below the middle of each, sloping and usually marked with a faint impressed spiral line or two above the carina, or having several striæ on the lower part of the slope, where the carina lies in the suture. The last 3 or 4 whorls revolve nearly in a plane, are markedly concave, with the outer edge raised in an erect flange or keel, the concavity marked with one or several spiral threads and distinct, arched growth-striæ. Last whorl slightly convex below the shoulder-angle, straight and slender below, marked below the middle with unequal, low spirals, most of them beaded.
Length 37.5, diam. 19 mm. Incomplete adult shells are much larger, diam. 28 mm., with about 15 whorls (5).
This species differs from C. domingensis Gabb by having the outer edge of the later whorls raised in a flange and by the smooth, not tuberculate early whorls. None of the larger specimens is complete (5).
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Conus jacksonensis (Meyer, 1885)
Per Meyer, il Conus jacksonensis è simile al Conus protractus, ma le spire presentano rigature spiraliformi(8).
Meyer named a new cone from the Jackson, C. jacksonensis, without adequately describing or figuring it. Dr. Charles Berry, formerly of the Geology Department, the Johns Hopkins University, kindly loaned the type of C. jacksonoisis, and it is figured herein. The specimen, as it exists today, consists of the apical whorls. They appear to be the characteristic type of the C. sauridens stock and probably are therefore the apical whorls of C. tortilis (9).
Jackson, Alabama
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Bibliografia
Consultata
(2) - Conrad (1835), “FOSSIL SHELLS OF THE TERTIARY FORMATION OF NORTH AMERICA
(3) - Conrad (1865), American Journal of Conchology Vol. 1 Part 2
(5) - Brown & Pilsbry (1911) – “Fauna of the Gatun Formation”
(7) - NEW AND OTHERWISE INTERESTING TERTIARY MOLLUSCA FROM TEXAS. BY GILBERT D. HARRIS,
(10) - Hendricks, Portell (2008) “ Late Eocene Conus (Neogastropoda: Conidae) from Florida, USA“
