Pyrunculus frequens

Abstract

Pyrunculus frequens (Boettger, 1902) Figs 19F, 20A–C * Coelophysis frequens n. sp. — Boettger 1902: 51. Coelophysis frequens Bttgr.—Boettger 1907: 207. Retusa frequens Boettger— Zilch 1934: 277, pl. 22, fig. 17. Retusa (Cylichnina) subangiostoma [sic] (Orbigny)— Berger 1953: 100, pl. 17, fig. 91 [non Retusa subangystoma (d’Orbigny, 1852)]. Retusa (Retusa) frequens Boettger — Csepreghy-Meznerics 1956: 123. R [etusa]. (C [ylichnina]). subangistoma [sic] (Orb.)— Sieber 1958: 163 [non Retusa subangystoma (d’Orbigny, 1852)]. non Retusa (Retusa) frequens Boettg.—Rado & Muţui 1970: 148, pl. 6, fig. 37 [= Pyrunculus sp.]. Type material. Lectotype (designated by Zilch 1934: 277), SMF 363160 - 12.2553a (glass plate 398), SL: 6.0 mm, MD: 1.8 mm, Coşteiu de Sus (Romania), illustrated in Zilch (1934: pl. 22, fig. 17). The specimen was destroyed during WW II, Fig 20C. Illustrated material. NHMW 1865/0015/0155, SL: 6.2 mm, MD: 3.3 mm, Lysice (Czech Republic), Figs 19F, 20A 1 –A 2. NHMW-ZOO-MO-75000-E-47049, SL: 8.0 mm, MD: 4.0 mm, Lysice (Czech Republic), Figs 20B 1 –B 2. Revised description. Shell medium sized, solid, moderately broad (SL/MD = 1.9), only last whorl visible. Periphery placed below mid-whorl (SL/ PH = 2.2), almost straight to faintly concave sides above periphery, forming angle of about 23°. Rounded at moderately contracting base. Apex moderately broad (MD/ApD = 2.3–2.5), truncated, apical plane slightly oblique (AP = 6°), deeply and narrowly umbilicate, delimited by sharply edged, trigonal crest. Surface smooth, slightly glossy. Growth lines delicate. Aperture only slightly longer than shell, very narrow down to mid-whorl (MD/AW = 11.2–11.3), distinctly widening anteriorly (MD/MAW = 2.0–2.4), resulting in high expansion rate (ER = 4.6–5.5). Outer lip thin, extending slightly above apex. Basal lip abapically slightly widening. Columella short, with narrow but prominent columellar callus bearing prominent central columellar fold. Columellar callus delimiting narrow umbilical chink. Parietal callus not developed. Discussion. This rare species is characterized by its relatively large size, solid shell for the genus, broad-conical outline, trigonal apical crest, and prominent columellar fold. Pyrunculus frequens (Boettger, 1902) might be related to the Pliocene to recent Mediterranean Pyrunculus ovatus (Jeffreys, 1871), which may form very similar shapes and has a trigonal crest (see Tringali & Oliverio 2001: figs 1–14). Pyrunculus ovatus, however, is much thinner-shelled, has a narrower, less truncated apex and lacks a columellar fold (see Landau et al. 2023: pl. 32). Pyrunculus frequens is superficially reminiscent of the extant Mediterranean Pyrunculus hoernesi (Weinkauff, 1866), which differs in its prominent apical sculpture and the lack of a columellar fold. The Late Miocene to Early Pleistocene Mediterranean Cylichna brocchii (Michelotti, 1847) lacks the truncated apex of Pyrunculus frequens and is weakly convex above the periphery (see Landau et al. 2023: pl. 40, figs 1–2). Paleoenvironment. Probably middle to outer neritic based on the occurrence at Lysice (own data, M.H.). Distribution in Central Paratethys. Badenian (Middle Miocene): Carpathian Foredeep: Lysice (Czech Republic) (hoc opus); Făget Basin: Coşteiu de Sus (Romania) (Boettger 1907).

Authors 3

1. Mathias Harzhauser

   Natural History Museum Vienna

   Affiliation as printed

   Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria mathias. harzhauser @ nhm. at; https: // orcid. org / 0000 - 0002 - 4471 - 6655

2. Bernard Landau Aachen

   University of Lisbon · Instituto Dom Luiz · Naturalis Biodiversity Center

   Affiliation as printed

   Naturalis Biodiversity Center, P. O. Box 9517, 2300 RA Leiden, Netherlands; Instituto Dom Luiz da Universidade de Lisboa, Campo Grande, 1749 - 016 Lisboa, Portugal; and International Health Centres, Av. Infante de Henrique 7, Areias São João, P- 8200 Albufeira, Portugal bernardmlandau @ gmail. com; https: // orcid. org / 0000 - 0002 - 7768 - 8494

3. Manuel António E. Malaquias

   University of Bergen · Natural History Museum Vienna

   Affiliation as printed

   Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria mathias. harzhauser @ nhm. at; https: // orcid. org / 0000 - 0002 - 4471 - 6655 & Department of Natural History, University Museum of Bergen, University of Bergen, PB 7800, 5020 - Bergen, Norway manuel. malaquias @ uib. no; http: // orcid. org / 0000 - 0002 - 9668 - 945 X & Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria mathias. harzhauser @ nhm. at; https: // orcid. org / 0000 - 0002 - 4471 - 6655