Allmonia inaequiplicata ( Cossmann & Peyrot, 1922 ) Harzhauser & Landau, 2019

Harzhauser, Mathias & Landau, Bernard, 2019, Turritellidae (Gastropoda) of the Miocene Paratethys Sea with considerations about turritellid genera, Zootaxa 4681 (1), pp. 1-136 : 94-96

Allmonia inaequiplicata ( Cossmann & Peyrot, 1922) new comb.

Figs 6 Ac, 27A 1 –A 2, 27B 1 –B 2, 27C 1 –C 2,

* Protoma quadriplicata mut. inaequiplicata nov. mut. — Cossmann & Peyrot, 1922: 59, nr. 440, pl. 1 fig. 26.

Protoma inaequiplicata Cossm. et Peyr. — Strausz, 1954: 40, pl. 1, fig. 18.

Protoma aff. quadriplicata (Bast.) — Csepreghy-Meznerics, 1954: 18, pl. 2, fig. 5.

Protoma cathedralis quadricincta Schaffer — Pavlovsky, 1957: 53, pl.1, figs 2a–b.

Protoma (Protoma) cathedralis telleri Hilber — Sieber, 1960: 264, pl. 2, fig. 4, pl. 3, fig. 8/23 [non Allmonia telleri ( Hilber, 1893) ].

Protoma cathedralis (Brongniart) — Kecskemétiné Körmendy, 1962: 86, pl. 9, fig. 25 [non Allmonia cathedralis ( Brongniart, 1823) ].

Protoma cathedralis (Brongniart) var. quadricincta Schaffer — Kecskemétiné Körmendy, 1962: 87, pl. 10, fig. 1.

Protoma proto quadriplicata Basterot, 1825 — Strausz, 1966: 112, pl. 4, figs 1–3 [non Turritella quadriplicata de Basterot, 1825 = Allmonia cathedralis ( Brongniart, 1823) ].

Protoma cathedralis Brongniart, 1823 — Strausz, 1966: 110, text-fig. 56, pl. 78, fig. 5 [non Allmonia cathedralis ( Brongniart, 1823) ].

Protoma cathedralis paucicincta Sacco — Kókay, 1967: 86.

Protoma proto (Basterot) 1825 — Bohn-Havas, 1973: 1042, pl. 3, figs 15–16 [non Turritella proto de Basterot, 1825 = Allmonia cathedralis ( Brongniart, 1823) ].

Protoma inaequiplicata Cossmann et Peyrot, 1922 — Dulai, 2015: 211, fig. 7.

Type material. Holotype illustrated in Cossmann & Peyrot (1922, pl. 1, fig. 26), Langhian (middle Miocene ), Saubrigues ( France). The specimen derives from the collection of Armand Degrange-Touzin , which is stored in the Muséum National d’histoire Naturelle Paris but the specimen could currently not be located (Jean-Michel Pacaud pers. comm., 2019).

Studied material. 4 spec. NHMW 1997z01278/2033, 1 spec. NHMW 2018/0297/0002, 1 spec. NHMW 2018/0297/0003, 1 spec. NHMW 2018/0297/0004, 1 spec. NHMW 2018/0297/0005, 36 spec. NHMW 2018/0297/0006; all Várpalota ( Hungary) .

Illustrated material. Figs 27A 1 –A 2 : NHMW 2018/0297/0002, SL: 46.5 mm, MD: 14.8 mm; Figs 27B 1 –B 2 : NHMW 2018/0297/0003, SL: 47.1 mm, MD: 13.7 mm; Figs 27C 1 –C 2 : NHMW 2018/0297/0004, SL: 48.7 mm, MD: 13.0 mm; all Várpalota ( Hungary).

Revised description. Shell s mall to medium sized, moderately slender, robust, consisting of about 16 teleoconch whorls. Protoconch unknown; earliest preserved teleoconch whorl bicarinate with small keels formed by sharp B and C spiral cord separated by narrow, weakly concave interspace; sutural ramp broad, flat to weakly convex. B cord slightly below mid-whorl. Two weaker spiral cords appear on sutural ramp on neanic whorls, which soon rival the B and C spirals in strengths; delicate s spiral cord may be intercalated; d spiral cord present but usu- ally largely covered by subsequent whorl. Spiral cords with convex tops on post-neanic whorls faintly scalloped by densely spaced growth lines. Spirals often forming two pairs separated by a slightly wider mid-whorl interspace. Spiral sculpture weakening in many specimens on last whorl. Delicate spiral threads may appear in interspaces and rarely also on primary cords. Whorl profile flat sided, somewhat telescoped on latest teleoconch whorls. Last whorl with marked basal angulation coinciding with spiral cord d. Base moderately low, markedly concave between angulation and fasciole. Very broad fasciole often with scalloping growth increments. Inner lip forming thick glossy sheet in parietal area, bordering fasciole. Outer lip missing. Lateral sinus with moderately steep angle; shallow, in adapical position. Basal sinus deeply incised, occasionally forming short, slightly deflected canal.

Shell measurements and ratios. 5 near complete specimens (n = 5) SL = 48.2 mm (σ = 1.7), MD = 13.9 mm (σ = 0.6); largest fragments suggest a maximum SL of ~ 60 mm; n = 10: AA: μ = 21.9° (σ = 1.6°), PA: μ = 13.4° (σ = 2.0°). Lateral sinus (n = 6): LS angle = 17.8° (σ = 1.3°), LS p = 0.8 (σ = 0.1), LS d = 7.4 (σ = 1.4). Discussion. We tentatively identify the Paratethyan specimens with the French Langhian Allmonia inaequipli- cata, following previous identifications by Strausz (1954) and Dulai (2015), based on the similarity in size, profile, and sculpture and the identical stratigraphic occurrence. This assignment remains preliminary as we have not seen the type of Allmonia inaequiplicata and have no information on the sculpture of its neanic whorls.

This small Allmonia species differs from A. paucicincta in its much smaller size and the constant sculpture of four main spiral cords, usually separated into two pairs, which is contrast to the three prominent spiral cords in A. paucicincta . It is distinctly less telescoped and lacks a subsutural collar on late teleoconch whorls. Overall, it appears like a dwarf morph of the early Miocene Allmonia cathedralis . Allmonia turoniensis ( Glibert, 1949) , from the Langhian of the Loire Basin, develops very similar sculpture on adult whorls. A comparison with topotypic specimens ( NHMW 1852/0028/0106) reveals major differences of the neanic whorls, which are almost smooth, covered only by delicate spiral threads and weakly convex instead of bicarinate.

Paleoenvironment. See generic discussion.

Distribution. Central Paratethys. Badenian (middle Miocene): Styrian Basin: Klockerberg at Wetzelsdorf ( Austria); Pannonian Basin: Várpalota, Pécsszabolcs, Ófalu ( Hungary) ( Kecskemétiné Körmendy 1962; Bohn-Havas 1973); Cserhát Mountains: Bán, Mátraszölös, Mátraverebély ( Hungary) (Csepreghy Meznerics 1969; Bohn-Havas 1973); Samobor hills: Samobor near Zagreb ( Croatia) ( Pavlovsky 1957).

Figures

FIGURE 1. Paleogeography of the Paratethys during the early Miocene (Burdigalian, Eggenburgian, Sakaraulian) and the middle Miocene (Langhian, Badenian, Tarkhanian) (modified after Popov et al. 2004 and Neubauer et al. 2015).

FIGURE 2. Miocene chronostratigraphy after Gradstein et al. (2012) with regional Paratethys stages after Popov et al. (2004) and Piller et al. (2007).

FIGURE 6. Growth line traces of Turritellidae species based on own data; bold: type species of genera; black: Paratethyan species; asterisk: non-Paratethyan species (unknown basal sinuses are left blank).

FIGURE 27.A–C.Allmonia inaequiplicata (Cossmann & Peyrot, 1922), Várpalota (Hungary). A1–A2. NHMW 2018/0297/0002. B1–B2. NHMW 2018/0297/0003. C1–C2. NHMW 2018/0297/0004.