Colubraria subobscura (Hoernes & Auinger, 1884)

Harzhauser, Mathias & Landau, Bernard M., 2024, The Colubrariidae, Eosiphonidae, Melongenidae, Pisaniidae, Prodotiidae and Tudiclidae (Gastropoda, Buccinoidea) of the Miocene Paratethys Sea, Zootaxa 5427 (1), pp. 1-110 : 7-11

Colubraria subobscura (Hoernes & Auinger, 1884)

Figs 2A–F , 3A , 4A–D

* Triton (Epidromus) subobscurum nov. form.—Hoernes & Auinger 1884: 181, pl. 22, figs 4–7.

Triton (Epidromus) Karreri nov. form.—Hoernes & Auinger 1884: 182, pl. 22, figs 8–10.

Triton (Epidromus) subobscurus Hö. Au. — Boettger 1902: 25.

Ranella kostejana n. sp. — Boettger 1902: 27.

Eutritonium (Epidromus) karreri (Hö Au.) — Boettger 1906: 39.

Charonia (Colubraria) karreri (Hoernes & Auinger) — Zilch 1934: 250, pl. 14, fig. 74.

Colubraria (Colubraria) subobscura (Hoernes et Auinger 1884) —Kojumdgieva in Kojumdgieva & Strachimirov 1960: 139, pl. 38, figs 3a–b.

Colubraria (Colubraria) karreri (Hoernes et Auinger 1884) —Kojumdgieva in Kojumdgieva & Strachimirov 1960: 139, pl. 38, figs 6a–b.

Colubraria subobscura (Hoernes et Auinger) — Vicián et al. 2017: 271, pl. 3, figs 6–7.

Colubraria karreri (Hoernes et Auinger, 1884) — Kovács 2022: 67, figs 2–5.

Colubraria subobscura (Hoernes et Auinger, 1884) — Kovács 2022: 67, figs 6–9.

Colubraria subobscura (Hoernes et Auinger, 1884) — Kovács & Vicián 2023: 224, figs 3A–B.

Type material. Lectotype (designated herein): NHMW 1874 /0025/0021, SL: 20.2 mm, MD: 8.6 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 4), Figs 2E 1 –E 3 . Paralectotypes: NHMW 1865 /0001/0183, SL: 25.0 mm , MD: 11.2 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 5), Figs 2C 1 –C 3 . NHMW 1854 /0035/0170, SL: 25.9 mm , MD: 10.8 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 6), Figs 2A 1 –A 3 . NHMW 2023 /0338/0001, SL: 29.1 mm , MD: 13.7 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 7), Figs 2F 1 –F 2 .

Illustrated material. NHMW 1859 /0037/0018a, SL: 40.6 mm , MD: 16.7 mm, Lăpugiu de Sus ( Romania), Figs 2B 1 –B 2 . NHMW 1859 /0037/0018b, SL: 32.4 mm , MD: 13.5 mm, Lăpugiu de Sus ( Romania), Figs 2D 1 –D 2 . NHMW 2023 /0338/0002, Lăpugiu de Sus ( Romania), Fig. 3A . NHMW 1856 /0007/0031, SL: 28.8 mm , MD: 11.3 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 8) as Colubraria karreri , Figs 4A 1 –A 3 . NHMW 1866 /0040/0272, SL: 19.1 mm , MD: 9.7 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 9) as Colubraria karreri , Figs 4B 1 –B 2 . NHMW 1866 /0040/0272a, SL: 21.9 mm , MD: 11.3 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 10) as Colubraria karreri , Figs 4C 1 –C 2 . SMF 373155 (old number XII 2565 a), holotype of Ranella kostejana Boettger, 1902 , CoŞteiu de Sus ( Romania), Figs 4D 1 –D 2 .

Additional material. 5 spec., NHMW 2023 /0338/0003, Lăpugiu de Sus ( Romania) ; 15 spec., NHMW 1859 /0037/0018, Lăpugiu de Sus ( Romania) ; 11 spec., NHMW 1855 /0043/0033, Lăpugiu de Sus ( Romania) . 10 spec., NHMW 1866 /0040/0272, Lăpugiu de Sus ( Romania) .

Revised description. Medium-sized, solid, moderately slender fusiform shell; apical angle 40–45°. Protoconch of about 2.5 whorls (nucleus not preserved), diameter ~900μm, height> 800μm. Teleoconch of up to nine whorls. Early teleoconch whorls convex with deeply incised suture. Sculpture of four spiral cords on first teleoconch whorl overriding narrow axial ribs bearing rounded beads at intersections, number of cords increasing to about eight on penultimate whorl by intercalation of secondary cords that rapidly become equal in strength. Starting from aperture, penultimate varix just under 360 degrees behind terminal varix; next varix about 270–300° behind penultimate. Earlier whorls with usually two varices per whorl, irregularly placed or aligned axially in some specimens. Last whorl attaining 52–56% of total height, regularly convex, base moderately constricted, bearing about 28–33 axial rows of spirally arranged beads, single secondary cord intercalated between primaries at periphery; fasciole weak, covered in prominent spiral cords. Aperture elongate, moderately narrow. Columella excavated in adapical half. Columellar callus forming thick, broad shield-like callus bearing several irregular denticles and granules in abapical half and two denticles at anal canal. Anal canal deeply incised, accentuated by parietal denticle. Outer lip weakly thickened with about 11 prominent, elongated denticles place close behind peristome. Prominent terminal varix. Siphonal canal moderately long, moderately narrow, slightly deflected to the left, shallowly notched.

Paratethyan synonyms. Colubraria karreri (Hoernes & Auinger, 1884) is based on subadult specimens, which lack the characteristic shield-like columellar callus. This synonymy is supported by the fact that both ‘species’ co-occur. As first revisers we give Colubraria subobscura (Hoernes & Auinger, 1884) precedence over Colubraria karreri (Hoernes &Auinger, 1884) . Ranella kostejana Boettger, 1902 , from CoŞteiu de Sus ( Romania), is a subjective junior synonym of Colubraria subobscura (Hoernes & Auinger, 1884) . It is based on a juvenile specimen.

Discussion. The growth rate of Colubraria subobscura is fairly constant, whereas in other colubrariids the growth rate is often irregular causing the whorl profile to be cyrtoconoid or the whorls tilted in relation to each other. Few Colubraria species have been described from the Miocene of the Circum-Mediterranean region. Colubraria miocaenica ( Michelotti, 1847) , from the Langhian of the Colli Torinesi, is a slenderer species with high whorls and sculpture of delicate beads (see Bellardi 1873: pl. 14, fig. 14). The specimen illustrated by Bellardi (1873) lacks the apex and is highly reminiscent of Caducifer Dall, 1904 [type species Triton truncatus Hinds, 1844 ; present-day, Indo-West Pacific]. In any case it is clearly unrelated to the Paratethyan species. Colubraria miocaenica sensu Cossmann, 1903 [non Michelotti, 1847], from the Early Miocene of France, is more similar to Colubraria subobscura and differs mainly in its slightly coarser sculpture and the subobsolete parietal denticle (see Cossmann 1903: pl. 4, figs 4–5). Lozouet (2021) proposed a placement of Colubraria miocaenica sensu Lozouet, 2021 [non Michelotti, 1847], from the Early Miocene of France, in Cumia Bivona, 1838 [type species Cumia decussata Bivona e Bernardi, 1838 = Cumia intertexta ( Helbling, 1779) , by monotypy, present-day, Mediterranean Sea]. According to Watters (2009: 272), Cumia species differ from Colubraria species in the character of their protoconch. Cumia has a small, papillate paucispiral protoconch suggestive of direct development, whereas Colubraria has a tall mammillate or conical multispiral protoconch suggesting at least a lecithotrophic larval phase. However, the importance of protoconch type in generic separation is questionable in the absence of other teleoconch characters, as planktotrophy is lost in so many gastropod genera. We await molecular data to confirm the separation of these two genera. In any case, the protoconchs of Colubraria subobscura and Colubraria miocaenica correspond to the larger, conical type typical for Colubraria .

The extant, cosmopolitan Colubraria obscura ( Reeve, 1844) differs in the less incised suture, slightly higher whorls, lacks the prominent granulae on the columellar callus and has less pointed beads.

Paleoenvironment. Unknown, probably derived from shallow marine environments corresponding to extant congeners ( Modica et al. 2015; Oliverio & Modica 2010).

Distribution in Central Paratethys. Badenian (Middle Miocene): Pannonian Basin: Letkés ( Hungary) ( Vicián et al. 2017); Făget Basin: CoŞteiu de Sus, Lăpugiu de Sus ( Romania) (Hoernes & Auinger 1884; Zilch 1934; Kovács 2022); Dacian Basin: Târnene, Urovene ( Bulgaria) (Kojumdgieva in Kojumdgieva & Strachimirov 1960).

Genus Metula H. Adams & A. Adams, 1853

Type species. Buccinum clathratum A. Adams & Reeve, 1850 [= Metula amosi Vanatta, 1913 ], subsequent designation by Kobelt (1876: 39). Present-day, Eastern Pacific.

Revised diagnosis. “ Shell medium-sized, moderately slender to very slender, whorls not or only slightly constricted at suture, body whorls very long. Nucleus stout, consisting of almost two smooth whorls. Aperture very long, narrow, elliptical, tapering to an acute angle at the posterior end, constricted at anterior end to form a short wide slightly recurved moderately emarginate canal. Siphonal fasciole low. Edge of inner lip forming a definite edge along pillar and parietal wall. Outer lip varicose, its inner edge bearing broad denticles that may be extended into short lirations.” ( Woodring 1928: 285; see also Cernohorsky 1971: 151 for Acamptochetus ).

Discussion. MolluscaBase Eds. (2023b) lists the following genera as synonyms of Metula : Acamptochetus Cossmann, 1901 , Agassitula Olsson & Bayer, 1972 , Antemetula Rehder, 1943 , Antimitra Iredale, 1917 , Colubrarina Kuroda & Habe in Kuroda et al. 1971 and Floritula Olsson & Bayer, 1972 . Of these, Acamptochetus [type species Murex mitraeformis Brocchi, 1814 , original designation by Cossmann (1901: 123), Pliocene, Mediterranean Sea] has frequently been used for Paratethyan and Mediterranean species. Protoconch features are important for the identification of extant Metula species ( Bouchet 1988). Recently, Lozouet (2021) documented that protoconchs were also important to distinguish Oligocene and Miocene species of this genus, which is also confirmed herein. Metula species occur in deep water environments ( Houbrick 1984; Bozzetti 1993).

Figures

FIGURE 1. Measurements for shell morphology; AA: apical angle, SL: shell length, MD: maximum diameter, LWH: last whorl height, AH: aperture height, AL: aperture length, AW: aperture width.

FIGURE 2. Colubraria subobscura (Hoernes & Auinger, 1884). A1–A3. NHMW 1854/0035/0170, paralectotype, Lăpugiu de Sus (Romania). B1–B2. NHMW 1859/0037/0018a, paralectotype, Lăpugiu de Sus (Romania). C1–C3. NHMW 1865/0001/0183, paralectotype, Lăpugiu de Sus (Romania). D1–D2. NHMW 1859/0037/0018b, paralectotype, Lăpugiu de Sus (Romania). E1–E3. NHMW 1874/0025/0021, lectotype, Lăpugiu de Sus (Romania). F1–F2. NHMW 2023/0338/0001, paralectotype, Lăpugiu de Sus (Romania).

FIGURE 3. A. Colubraria subobscura (Hoernes & Auinger, 1884), NHMW 2023/0338/0002, Lăpugiu de Sus (Romania). B. Metula kovacsi nov. sp., NHMW 1867/0019/0078, holotype, CoŞteiu de Sus (Romania). C1–C2. Metula aliceae nov. sp. NHMW 1846/0037/0277a, paratype, Baden (Austria).

FIGURE 4. Colubraria subobscura (Hoernes & Auinger, 1884). A1–A3. NHMW 1856/0007/0031, Lăpugiu de Sus (Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 8) as Colubraria karreri. B1–B2. NHMW 1866/0040/0272, Lăpugiu de Sus (Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 9) as Colubraria karreri. C1–C2. NHMW 1866/0040/0272a, Lăpugiu de Sus (Romania), illustrated in Hoernes & Auinger (1884: pl. 22, fig. 10) as Colubraria karreri. D1–D2. SMF 373155, holotype of Ranella kostejana Boettger, 1902, CoŞteiu de Sus (Romania).