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Species Eubaculites vagina Forbes 1846 | ||||||
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Diagnosis / Definition: | ||||||
Kennedy & Henderson (1992): DESCRIPTION.- The whorls expand quite rapidly, and the shell is slightly curved. The whorl section is compressed, the whorl breadth to height ratio varying between 0.6 and 0.73. The dorsum is broad and flattened, the venter narrow and tabulate, with sharp or narrowly rounded edges. In feebly ornamented variants the whorl section is more compressed, dorsal flanks are divergent, the mid-flank region rounded, and the outer flanks convergent. In strongly nodate variants the whorl section is less compressed, the inner flanks flattened and divergent, with maximum breadth at the mid-lateral tubercle and with flattened to feebly concave ventral flanks in costal section. The venter is distinctly tabulate from as little as 9 mm whorl height, the only smaller specimens seen being poorly preserved, but with a narrowly rounded venter at a whorl height of 8 mm. A wide range of variation in ornament is attreibuted to the species. At one extreme (Pl. 5, figs. 10-13; Pl. 7, figs. 4-9, 10-12; Pl. 8, figs. 10-12) are variants ornamented by growth lines only. These are sharp on the shell surface (e.g. Pl. 5, fig. 10), but subdued on the mould (Pl. 5, fig. 12). They are broadly convex over dorsum, sweep back across the dorsolateral region, are markedly concave on the dorsal half of the flank, but projected strongly forwards on the ventral half, to intersect the line of the venter at an acute angle. They flex back and are convex over the juncture of flank and venter, passing straight across the venter. Stronger ornament takes the form of broad, ill-defined ribs on the dorsal half of the flanks that strengthens into a feeble mid-lateral node, as in BMNH C2582 and C 73567. In specimens such as BMNH C77594 (Pl. 7, fig. 13-15), ornament is better differentiated, with a rib index of 2-3.5. The ribs are distant, low and transverse on the dorsal half of the flank, and strengthen into a crescentic mid-lateral tubercle, but decline on the outer flank. As ornament strengthens, a second, dorsolateral tubercle develops, a condition well illustrated by the lectotype (Pl. 7, fig. 16-18), with a rib index of 3. As well as this variation between individuals, ornament changes, generally strengthening, as size increases (Pl. 7, figs. 1-3, 13-18; Pl. 8, figs. 1-9). A notching of the tabulate venter may develop (Pl. 7, fig. 16; Pl. 8, fig. 3), producing an undulose profile to the shell margin but is of variable development within and between individuals. In coarsly ornamented individuals, the dorsolateral tubercle is markedly elongated parallel to the margin of the shell (e.g. BMNH C26300), and the dorsolateral margin undulose in profile (Pl. 9, fig. 13); a broad rib links to the lateral tubercle, which varies from crescentic and oblique (BMNH C7759; Pl. 9, fig. 1-2) to elongated parallel to the length of the shell (BMNH C51141; Pl. 8, fig. 5). The largest specimen seen (BMNH C51140; Pl. 10, figs. 1-3) has a whorl height of 49.5 mm, a whorl breadth to height ratio of 0.6, and a rib index of 5. A marked concavity occupies the ventral part of the flanks, and strengthened growth lines - or riblets - link dorsolateral and mid-lateral tubercles, and extend to the ventrolateral margin. One fragment, BMNH C51146 (Pl. 9, figs. 9-10), shows the aperture, with short dorsal and long ventral rostrum. Suture (Text-fig. 1C, F) with very broad E with very broad shallow medium saddle; E/L narrower, bifid, L broader than E/L and bifid, L/U, much broader than other saddles, U of intermediate width. All saddles are broad-based, and lobes E, L and U have wide necks. |
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Discussion / Comments: | ||||||
Kennedy & Henderson (1992): TYPES.- Lectotype, here designated, is BMNH C49726, the original of Forbes (1846, pl. 10, fig. 4), GSC R10488; paralectotypes are BMNH C51140-51150, from the Valudavur Formation of Pondicherry, south India. There are also the following topotypes: BMNH C2582, C77593-77598 (ex Kaye Collection); C2583, C73567-73569, C73590 (ex Marsham Collection); C2597 (ex Forbes Collection); C26299-26300 (ex Spath Collection); C77599-77600. DIMENSIONS.- Wb Wh Wb:Wh Dorsum Venter Rib index BMNH C51144 7.8 11.8 0.66 4.8(61.5) 1.0(12.8) Smooth BMNH C51151 11.0 15.7 0.70 6.3(57.3) 2.0(18.2) Smooth BMNH C51145 — 21.5 — 9.1(—) 4.1(—) 3 BMNH C51149 15.0 23.6 0.64 10.4(69.0) 3.0(12.7) 3 BMNH C77594 16.5 23.7 0.69 11.8(71.5) 4.0(24.2) Smooth BMNH C51142 16.0 23.8 0.67 11.0(68.8) 4.4(27.5) Smooth BMNH C51150 16.6 25.9 0.64 10.4(62.6) 3.2(19.2) 2 BMNH C51148 19.3 26.7 0.72 16.3(84.4) 5.1(19.1) 2.5 BMNH C51143 19.3 28.2 0.68 13.2(68.3) 3.2(16.6) 2 BMNH C51147 19.0 29.2 0.65 17.0(89.5) 3.0(15.8) 2 BMNH C26300 21.4 30.0 0.71 17.0(79.4) 3.8(17.8) 2 BMNH C51441 21.1 30.6 0.69 14.9(70.6) 3.6(17.1) 2 BMNH C49762 21.5 32.0 0.67 16.0(74.4) 5.4(16.9) 3 BMNH C51146 — 36.0 — 19.1(—) 9.2(—) — BMNH C77953 26.5 38.8 0.69 19.0(71.7) 5.5(20.8) 2 BMNH C51140 32.0 50.0 0.64 24.5(76.6) 8.7(27.2) 3 (measurements were taken at the larger end of the specimen; width of dorsum and venter, expressed as a percentage of whorl breadth are shown in parentheses) DISCUSSION.- The diagnostic features of the type assemblage of E. vagina are the presence of a tabulate venter from an early stage, and binodose ornament on the flanks of a shell that is slightly curved, with a moderately high expansion rate. When compared with other species, these differ as follows; Eubaculites carinatus (Morton, 1834, p. 4, pl. 13, fig. 1; holotype is no 72866 in the collections of the Academy of Natural Sciences, Philadelphia; Text-fig. 5A-C), originally described from the Maastrichtian Prairie Bluff Chalk of Wilcox County, Alabama, has the tabulate venter of the present species, but a flank ornament of concave of concave ribs only, without tubercles. The name carinatus has priority over Baculites tippaensis Conrad, 1858 (p. 334, pl. 35, fig. 27) and B. spillmani Conrad, 1858 (p. 335, pl. 35, fig. 24), originally described from the Owl Creek Formation of Tippah County, Mississippi; and Baculites lyelli d’Orbigny 1847a (pl. 1, figs. 3-7), originally described from Quiriquina Island, Chile among others (see Kennedy 1987, p. 195 for an extensive synonymy). Eubaculites labyrinthicus (Morton, 1834, p. 44, pl. 13, fig. 10, syntypes are nos 72868-72869 in the collection of the Academy of Natural Sciences, Philadelphia; Text-fig. 5D-K) originally described from the Maastrichtian Prairie Bluff Chalk of Alabama, is known in that region as fragments with whorl heights of up to 17.5 mm. The dorsum is flattened, with a dorsolateral node elongated parallel to the length of the shell, linked by a low broad rib to a similarly elongated but obliquely placed mid-lateral tubercle that gives rise to delicate prorsiradiate riblets and striae, which also intercalate. The rib index is 2. This is similar to the ornament of E. vagina, but the venter of E. labyrinthicus is fastigiate rather than broadly tabulate, immediately differentiating the two species. Eubaculites ootacodensis (Stoliczka, 1866) (= Baculites vagina Forbes var. Ootacodensis Stoliczka, 1866, p. 199, pl. 90, figs. 14, ?15) (lectotypes, designated by Kennedy 1987, p. 195 in the original of Stoliczka, 1866, pl. 90, fig. 14, shown here as Text-fig. 5L-P), originally described from Ootacod, south India, has a binodose lectotype with fastigiate venter, which separates it from E. vagina (see Kennedy 1987, p. 194 for a synonymy). E. simplex (Kossmat, 1895) (=Baculites vagina Forbes var. nov. simplex Kossmat, p. 156 (60), pl. 19 (5), figs. 13a-b, non 14a-b (= E. carinatus)) (lectotype, designated by Kennedy 1987, p. 195, is the original of Kossmat 1896, pl. 19 (5), fig. 13; Text-fig. 6D-F), from Ariyalur, south India, has a completely smooth lectotype, with a narrowly rounded, fastigiate venter, immediatlely separating it from E. vagina. Kennedy 1987, p. 194) thought simplex to be a synonym of E. ootacodensis, but study of large collections from Western Australia show, rather, that it is the senior synonym of Eubaculiceras compressum Brunnschweiler, 1966 (p. 36, pl. 4, figs. 15-17; pl. 5, figs. 1-3; text-fig. 21), E. fastigiatum Brunnschweiler, 1966 (p. 37, pl. 5, figs. 7-9; text-fig. 22), Cardabites tabulatus Brunnschweiler, 1966 (p. 38, pl. 5, figs. 12-15; text-fig. 23), and Cardabites scimitar Brunnschweiler, 1966 (p. 38, pl. 5, figs. 16-21; text-fig. 24). The Australian material has both fastigiate and narrowly tabulate venters, and feeble undulations on the flank of some specimens. The venter of tabulate variants is always much narrower than in smooth variants of E. vagina. Eubaculites latecarinatus (Brunnschweiler, 1966, p. 33, pl. 3, figs. 13-14; pl. 4, figs. 1-5; text-figs. 17-18), of which Giralites quadrisulcatus Brunnschweiler, 1966 (p. 35, pl. 4, figs. 11-14; text-fig. 20) and Eubaculites ambindensis Collignon, 1971 (p. 18, pl. 646, fig. 2393) are synonyms (see revision in Klinger (1976), and Klinger and Kennedy (in Klinger et al. 1980, p. 296, text-figs. 2-4, 5d)), is characterized by a lack of flank ornament and a broad tabulate venter. Lack of ornament alone distinguishes it from ribbed and tuberculate specimens of E. vagina, and large collections of latecarinatus from Zululand never show significant flank ornament, although the venter may become notched, so that the species and populations seem distinct enough. More difficult is the distinction between E. latecarinatus and the smooth Eubaculites in the Pondicherry fauna (Pl. 5, figs. 10-13; Pl. 7, figs. 4-9, 10-12; Pl. 8, figs. 10-12; Pl. 9, figs. 9-10; see also Stoliczka 1866, pl. 91, fig. 1 (Text-fig. 6A-C, G-I), and pl. 91, fig. 2 (Text-fig. 6J-L; the latter feebly binodose at the larger end), and the question as to whether or not these smooth individuals should be segregated as E. latecarinatus rather than being referred to E. vagina. Some E. latecarinatus at least have a much more compressed whorl section than the smooth Pondicherry forms, which also lack the pronounced corrugated venter of South African specimens (e.g. Klinger and Kennedy in Klinger et al. 1980, fig. 4) and their dorsal grooves and median ridge (Klinger and Kennedy in Klinger et al. 1980, fig. 30). On balance, given the apparent transition from smooth to ribbed and tuberculate individuals in the Pondicherry assemblages (not seen in South African and Australian E. latecarinatus), we treat them as a single species, admitting however, that some smooth individuals of E. vagina are morphologically inseparable from some E. latecarinatus. OCCURRENCE.- Maastrichtian of Pondicherry, south India, and Madagascar. Zululand representatives (Klinger 1976) may be better referred to E. labyrinthicus (Morton, 1834). |
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Systematics: | ||||||
41 Subordo Ancyloceratina Superfamilia Turrilitaceae Familia Baculitidae Genus Eubaculites Species Eubaculites vagina |
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Synonym list: | ||||||
Kennedy & Henderson (1992): 1846 Baculites vagina Forbes. - Forbes : p.114 pl. 10; fig. 4
non 1846 Baculites vagina Forbes. - Darwin : p.216 [E. carinatus (Morton, 1834)]
1847 Baculites ornatus d'Orbigny. - d'Orbigny : pl. 3, fig. 3-6
1850 Baculites vagina Forbes. - d'Orbigny : p.215
p 1866 Baculites vagina Forbes. - Stoliczka : p.198 pl. 91; fig. 1-6 [non var. ootacodensis, p. 199, pl. 90,
fig. 14-15]
1895 Baculites vagina Forbes. - Kossmat : 155(59) pl. 19(5); fig. 17 [(a) Typische Form]
non 1897 Baculites vagina Forbes. - Kossmat : pl. 6; fig. 4 [= E. carinatus (Morton, 1834)]
1898 Baculites vagina Forbes. - Crick : p.78 pl. 17; fig. 5
non 1906 Baculites vagina var. cazadorana Paulcke. - Paulcke : p.11 pl. 16; fig. 5a-c
non 1906 Baculites vagina Forbes. - BOULE et al. : 45(65) pl. 8 (15); fig. 3
non 1923 Baculites vagina Forbes. - Spengler : p.54 pl. 4; fig. 9
non 1924 Baculites cf. vagina var. otacodensis Stoliczka. - Crick : p.140 pl. 9; fig. 4-5 [? E. carinatus (Morton, 1834)]
non 1924 Baculites cf. vagina var. simplex Kossmat. - Crick : p.140 pl. 9; fig. 6-7 [? = E. carinatus (Morton, 1834)]
non 1924 Baculites cf. vagina Forbes. - Crick : p.130 pl. 9; fig. 1-3 [= E. carinatus (Morton, 1934) and E.
latecarinatus (Brunnschweiler, 1966)]
p 1925 Baculites vagina Forbes. - Diener : p.63
non 1926 Eubaculites vagina Forbes. - Spath : p.80
non 1930 Baculites vagina Forbes. - Wetzel : p.90 pl. 10; fig. 3-4 [= E. carinatus (Morton, 1834)]
non 1931 Baculites vagina Forbes. - Basse : p.20 pl. 2; fig. 6-10
non 1936 Baculites vagina var. vanhoepeni Venzo. - Venzo : 116(58) pl. 10 (6); fig. 11-12 [= Baculites vanhoepeni]
non 1940 Eubaculites vagina Forbes. - Spath : text-fig. 1a [= E. carinatus (Morton, 1834)]
non 1966 Eubaculites vagina Forbes. - BRUNNSCHWEILER : p.29 pl. 1, fig. 7;
pl. 2, fig. 1-14;
text-fig. 12-14
1971 Eubaculites vagina Forbes. - COLLIGNON : p.15 pl. 645; fig. 2391
1976 Eubaculites vagina Forbes. - KLINGER : p.87 pl. 35, fig. 1-4;
pl. 36, fig. 1-4;
pl. 37, fig. 1-5;
pl. 38, fig. 1-3, ?4;
pl. 39, fig. 2;
pl. 42, fig. 1 [non fig. 4, 7, 9, 11; pl. 43, fig. 5-12]
1977 Baculites vagina Forbes. - Kennedy : text-fig. 31.1-3
1980 Eubaculites vagina Forbes. - KLINGER & Kennedy : p.299 text-fig. 5a-c
1987 Eubaculites vagina Forbes. - Kennedy : p.194
1989 Eubaculites Spath. - Kennedy : text-fig. 17i-j
1992 Eubaculites vagina Forbes. - Kennedy & Henderson : p. 715, 721, 723, 72 pl. 5, fig. 10-13;
pl. 7, fig. 1-18;
pl. 8, fig. 1-12;
pl. 9, fig. 1-13;
pl. 10, fig. 1-3;
text-fig. 1C, F
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Stratigraphy - relative ages: | ||||||
Maastrichtian: Kennedy & Henderson (1992) |
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References: | ||||||
Forbes,E.. (1846): Darwin,C.. (1846): d'Orbigny,A. (1847): d'Orbigny,A. (1850): Stoliczka,F.. (1866): Kossmat,F.. (1895): Kossmat,F.. (1897): Crick,C.G.. (1898): Paulcke,W.. (1906): BOULE,M..; LEMOINE,P.. and THÉVENIN,A.. (1906): Spengler,E.. (1923): Crick,G.C.. (1924): Diener,C.. (1925): Spath,L.F.. (1926): Wetzel,W.. (1930): Basse,E.. (1931): Venzo,S.. (1936): Spath,L.F.. (1940): BRUNNSCHWEILER,R.o.. (1966): COLLIGNON,M.. (1971): KLINGER,H.C.. (1976): Kennedy,W.J.. (1977): KLINGER,H.C.. and Kennedy,W.J.. (1980): Kennedy,W.J.. (1987): Kennedy,W.J.. (1989): Kennedy,W.J.. and Henderson,R.A.. (1992): |
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Anonymous: Unedited TaxonConcept data | ||||||
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