Monteiroconus boeckhi (Halaváts, 1884), Halavats, 1884

Harzhauser, Mathias & Landau, Bernard, 2016, A revision of the Neogene Conidae and Conorbidae (Gastropoda) of the Paratethys Sea, Zootaxa 4210 (1), pp. 1-178 : 104-105

Monteiroconus boeckhi (Halaváts, 1884)

Figs 17 O, 24D1–D6, 24E1–E3, 24F1–F3

Conus (Lithoconus) Aldrovandi Brocc. — Hoernes & Auinger 1879: 25, pl. 4, fig. 2 [non Conus aldrovandi Brocchi, 1814 ].

Conus (Chelyconus) Böckhi nov. form.—Halaváts 1884: 174, pl. 4, figs 1a–c.

[ Conus (Lithoconus) ] pseudaldrovandi Sacc. — Sacco 1893a: 17 [nov. nom. pro Conus aldrovandi in Hoernes & Auinger 1879 , pl. 4, fig. 2].

Conus (Chelyconus) vindobonensis boeckhi Halaváts, 1884 — Strausz 1966: 458, pl. 69, figs 1–2.

Type material. The holotype was stored in the collection of the Geological and Geophysical Institute of Hungary in Budapest but seems to be lost (pers. comm. Klára Palotás); middle Miocene , Badenian (Langhian). The type locality of Conus pseudaldrovandi Sacco, 1893 , considered to be a junior synonym of M. boeckhi , is the middle Miocene (Badenian) locality Ritzing in Austria .

Studied material. 1 spec. NHMW 1870/0037/00021, 1 spec. NHMW 1870/0037/0002, 6 spec. NHMW 1930 / 0006/0037, Ritzing ( Austria).

Illustrated material. Figs 24 D1–D6, 17O: Ritzing ( Austria): SL: 72.6 mm, MD: 45.5 mm, NHMW 1930/0006/ 0037; Figs 24 E1–E3: Ritzing ( Austria): SL: 81.5 mm, MD: 51.2 mm, NHMW 1870/0037/0002, illustrated in Hoernes & Auinger (1879, pl. 4, fig. 2), holotype of Conus pseudaldrovandi Sacco, 1893 ; Figs 24 F1–F3: Ritzing ( Austria), SL: 54.5 mm, MD: 31.8 mm, NHMW 1930/0006/0037.

Revised description. Moderately large shells, up to 81 mm in height; about 10 teleoconch whorls; early spire conical with nearly flat, weakly striate to nearly smooth spire whorls; late spire strongly depressed with slightly concave, faintly striate whorls and somewhat irregular, deeply impressed, irregular suture; subsutural flexure deep, strongly curved, strongly asymmetrical. Last whorl conical with distinct shoulder, position of maximum diameter directly below angulation; very weak and somewhat irregular constriction below shoulder within the adapical third and distinct constriction at base. Fasciole short, strongly raised; siphonal canal short, recurved, thickened; inner lip broad, twisted. Colour pattern in UV light comprising axially elongated blotches parallel to the subsutural flexure on spire, slightly narrower than the interspaces; blotches continue via shoulder on last whorl. Last whorl covered by 3–4 broad bands and small dashes and blotches in the interspaces; position of bands variable but typically in some distance from shoulder, at mid-whorl and in lower third of last whorl.

Shell measurements and ratios. Only four adult shells are available: largest specimen: SL: 81.5 mm, MD: 51.2 mm, mean SL: 73.5 mm (σ = 5.7), mean MD: 45.5 mm (σ = 4.2), spire angle (without high conical initial part): µ = 142, 3° (σ = 9.5), last whorl angle: µ = 38.8° (σ = 0.96), LW: µ = 1.6 (σ = 0.07), RD: µ = 0.70 (σ = 0.03), PMD: µ = 0.95 (σ = 0.02), RSH: µ = 0.11 (σ = 0.02); the holotype is a subadult specimen: SL: 47 mm, MD: 28 mm (according to Halaváts 1884).

Discussion. The illustration of the holotype of Monteiroconus boeckhi from Hidas shows the characteristic colour pattern, which is also preserved in the specimens from Ritzing. Therefore, Conus pseudaldrovandi Sacco, 1893 , which was established by Sacco (1893a) for the specimen from Ritzing illustrated in Hoernes & Auinger (1879, pl. 4, fig. 2), is a subjective junior synonym of C. boeckhi . In their discussion of Conus aldrovandi, Hoernes & Auinger (1979) also referred to the specimen from Grund discussed by Hörnes (1851, pl. 1, fig. 2). Doderlein (1863) proposed Conus hornesi as new name for this shell from Grund in Austria, which is not conspecific with either M. boeckhi or M. aldrovandi . Despite some similarities, the Italian Pliocene C. aldrovandi differs from both Paratethyan species in its convex spire whorls and the position of the aperture distinctly below the shoulder of the preceding whorl. The lack of spiral striae on the spire allows a clear separation from M. mojsvari . Moreover, the ice cream cone shaped last whorl, the conspicuous, swollen fasciole and the colour pattern of broad bands allow a separation from all other Paratethyan species.

Paleoenvironment. The mollusc assemblage and geological situation of Ritzing suggests sandy fore shore settings in an embayment of the Pannonian Basin (Harzhauser et al. 2014 and references therein).

Distribution in Paratethys. Badenian (middle Miocene): Pannonian Basin: Hidas ( Hungary) (Halaváts 1884); Oberpullendorf Basin: Ritzing ( Austria) ( Hoernes & Auinger 1879).

Figures

FIGURE 24 A 1 – A 3. Monteiroconus antiquus (Lamarck, 1810), Gainfarn (Austria), NHMW 2016 / 0048 / 0001. 24 B 1 – B 3. Monteiroconus antiquus (Lamarck, 1810), Gainfarn (Austria), NHMW 1970 / 1396 / 1486. 24 C 1 – C 3. Monteiroconus antiquus (Lamarck, 1810), Gainfarn (Austria), NHMW 1856 / 0050 / 0112. 24 D 1 – D 6. Monteiroconus boeckhi (Halaváts, 1884), Ritzing (Austria), NHMW 1930 / 0006 / 0037. 24 E 1 – E 3. Monteiroconus boeckhi (Halaváts, 1884), Ritzing (Austria), NHMW 1870 / 0037 / 0 0 0 2. 24 F 1 – F 3. Monteiroconus boeckhi (Halaváts, 1884), Ritzing (Austria), NHMW 1930 / 0006 / 0037. 24 G 1 – G 3. Monteiroconus conicomaculatus (Sacco, 1893), Mikulov-Kienberk (Czech Republic), NHMW 1860 / 0001 / 00054.