Isara hoernesi
Creators: name: Harzhauser, Mathias
name: Landau, Bernard
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Mitridae
Isara
Isara hoernesi

description: Isara hoernesi (Mayer, 1864)
Figs 12A 1 –A 2, B 1 –B 2, C 1 –C 2, D 1 –D 2, E 1 –E 2, F 1 –F 2, G 1 –G 2, H 1 –H 2
Mitra aperta Bell. — Hörnes 1852b: 97, pl. 10, figs 1–3 [non Mitra aperta Bellardi, 1850].
* Mitra Hoernesi Mayer — Mayer 1864: 82. [nov. nom for Mitra aperta Hörnes 1852b non Bellardi, 1850].
Mitra aperta Bell. — Auinger 1871: 8 [non Mitra aperta Bellardi, 1850].
Mitra fusiformis Brocc. — Hoernes & Auinger 1880: 75, pl. 8, fig. 26 [non Episcomitra fusiformis (Brocchi, 1814)].
Mitra Hörnesi Mayer — Fontannes 1880: 84.
Mitra multistriata May.-Eym.— Mayer-Eymar 1890: 299 [non Bellardi, 1887].
Mitra multistriata Mayer-Eymar — Mayer-Eymar 1891: 339, pl. 10, fig. 7 [non Bellardi, 1887].
? Mitra (Mitra) multistriata Bell. — Boettger 1906: 7.
? Mitra (Mitra) aff. graviuscula Bell. — Boettger 1906: 8.
Mitra ambigua var. Hoernesi Mayer— Friedberg 1911: 13, text-fig. 3.
Mitra ambigua hörnesi Mayer — Csepreghy-Meznerics 1954: 48, pl. 6, fig. 18.
? Mitra fusiformis Br. —Strausz 1954: 75, pl. 4, fig. 83 [non Brocchi, 1814].
Mitra aperta Bellardi — Pavlovsky 1957: 53, pl. 1, figs 10a–b.
M [itraria]. (M [itraria].) ambigua hörnesi (May.)— Sieber 1958a: 153.
Mitraria (M.) ambigua hörnesi (May.) — Sieber 1958b: 149.
Mitra (Mitraria) friedbergi var. hoernesi (Mayer, 1864) —Kojumdgieva in Kojumdgieva & Strachimirov 1960: 159, pl. 42, fig. 6.
? Mitra hoernesi Mayer, 1864 — Strausz 1966: 362, pl. 41, figs 15–18.
Mitra (Mitra) multistriata Mayer-Eymar — Cernohorsky 1976: 377, pl. 323G, fig. 6 [non Bellardi, 1887].
Mitra hoernesi Mayer, 1864 — Cernohorsky 1976: 378.
Mitraria (Mitraria) friedbergi (Cossmann, 1912) — Popa et al. 2014: 15, pl. 4, fig. 6 [non Cossmann, 1912].
non Mitra (Mitraria) friedbergi hoernesi Mayer — Kókay 1966: 62, pl. 9, fig. 7 [= Fraudiziba mathiasi (Bałuk, 1997)].
Type material. Lectotype (designated herein): NHMW 1846 /0037/0097c, SL: 23.7 mm, MD: 10.1 mm, Steinebrunn (Austria), illustrated in Hörnes 1852b: 97, pl. 10, fig. 2, figs 12A 1 –A 2. Paralectotype: NHMW 1860 /0001/0116, SL: 25.3 mm, MD: 10.5 mm, Mikulov (Czech Republic), illustrated in Hörnes 1852b: 97, pl. 10, fig. 3, figs 12B 1 –B 2.
Additional material. Inv. Nr. t3350, SL: 25.1 mm, MD: 10.0 mm, Lăpugiu de Sus (Romania), holotype of Mitra multistriata Mayer-Eymar, 1890 [non Bellardi, 1887], illustrated in Mayer-Eymar (1891, pl. 10, fig. 7), stored in the collection of the Naturhistorisches Museum Basel (Switzerland), figs 12C 1 –C 2; NHMW 1855/0045/0383, SL: 25.3 mm, MD: 10.3 mm, Mikulov (Czech Republic), figs 12F 1 –F 2; NHMW 1868/0001/0397a, Lăpugiu de Sus (Romania), illustrated in Hoernes & Auinger (1880, pl. 8, figs 26a–b); NHMW 1860/0040/0045, SL: 34.7 mm, MD: 13.2 mm, Lăpugiu de Sus (Romania), figs 12E 1 –E 2; NHMW 1851/0002/0014, SL: 30.3 mm, MD: 11.7 mm, Grund (Austria), illustrated in Hörnes 1852b: 97, pl. 10, fig. 1, figs 12G 1 –G 2; NHMW 1865/0001/0170a, SL: 38.4 mm, MD: 14.3 mm, Lăpugiu de Sus (Romania), figs 12D 1 –D 2; NHMW 1865/0001/0170b, SL: 39.6 mm, MD: 14.4 mm, Lăpugiu de Sus (Romania), figs 12H 1 –H 2.
Revised description. Shell medium sized, broad to moderately broad ovoid, with impressed suture. Protoconch unknown. Teleoconch of eight whorls. Early teleoconch whorls moderately convex; convexity distinctly increasing on last two spire whorls. Sculpture on early spire whorls consisting of five broad, flattened spiral cords separated by narrow grooves (very weak in some specimens); abapical spiral cord partly covered by following whorl; adapical two spiral cords partly bifurcated by weak secondary grooves. Spiral sculpture becoming obsolete on fourth to fifth teleoconch whorls. Penultimate and last whorls smooth, aside from about 15 spiral cords on base and fasciole, increasing in strength abapically. Last whorl broad ovoid moderately constricted with distinct basal concavity. Aperture ovoid, moderately wide to wide; posterior sinus indistinct. Columellar callus broad, extending from adapical columellar fold to tip of siphonal canal. Columella with four prominent columellar folds, weakening abapically. Outer lip thin. Siphonal canal short to moderately short, moderately wide to wide, straight, with shallow anterior notch.
Shell measurements and ratios. SL = 25.2–39.63 mm, MD: 10.0– 14.4 mm, AA = 44–46°, SL/ MD: 2.4–2.6, AL/AW: 3.6–4.5, AH/S: 2.7–3.1.
Discussion. This species is morphologically extremely similar to the extant Isara cornea (Lamarck, 1811) from the western Mediterranean and the Azores. Isara hoernesi (Mayer, 1864) agrees with I. cornea in size and shell variability and differs only in the coarser spiral sculpture on early teleoconch whorls. We therefore assume that both species are closely related and place it in the genus Isara H. Adams & A. Adams, 1853.
Already Bellardi (1887a: 43) doubted that the Viennese shells described by Hörnes (1852b) as Mitra aperta were conspecific with the Pliocene Italian species. Indeed, Episcomitra aperta (Bellardi, 1887) differs from the Paratethyan species clearly in its more slender outline (see syntype in Ferrero-Mortara et al. 1981: 153, pl. 35, figs 14a–b; Chirli 2002, pl. 16, figs 1–6). Consequently, Mayer (1864) introduced Mitra hoernesi as new name for the three specimens described and illustrated by Hörnes (1852b: pl. 10, figs 1–3).
Mayer-Eymar (1890, 1891) described this species as Mitra multistriata. This name, however, was already preoccupied for an early Miocene species from Italy by Bellardi (1887a: 40). As we consider Mitra multistriata MayerEymar, 1890 to be a subjective junior synonym Mitra hoernesi Mayer, 1864, no replacement name is necessary.
Mitra brevis Bellardi, 1887, from the late Miocene of Stazzano (Italy), might be a subjective junior synonym of Isara hoernesi (Mayer, 1864) differing only in the less convex spire whorls (see Ferrero-Mortara et al. 1981: 147, pl. 40, figs 7a–b). Similarly, Episcomitra brevis as described by Landau et al. (2013, pl. 33, fig. 1) from the Serravallian of Turkey, is comparable in shape, but differs in its smaller size (SL: 13.6 mm) and lower and broader spire. The early Miocene Italian Mitra turbinata Bellardi, 1887 is another stout ovoid species, but differs in its lower spire (see syntype in Ferrero-Mortara et al. 1981, pl. 45, figs 3a–b).
The Pliocene Mitra obesa Foresti, 1868 is a comparably stout ovoid species, but differs in its lower spire, the even stockier last whorl and is slightly smaller (SL: 18 mm) (see Foresti 1868: 505, pl. 2, figs 14–16; Chirli 2002: 36, pl. 18, figs 4–5).
Palaeoenvironment. The specimens from Steinebrunn and Mikulov derive from shallow marine, inner neritic environments (own data).
Distribution in Central Paratethys. Badenian (middle Miocene): Voronyaky Hills: Jasionów (Yaseniv) (Ukraine) (Friedberg, 1911); Vienna Basin: Steinebrunn (Austria), Mikulov (Czech Republic); Pannonian Basin: Zapresic-Brijeg (Croatia) (Pavlovsky 1957), Sámsonháza (Hungary) (Csepreghy-Meznerics 1954); Făget Basin: Lăpugiu de Sus (Romania) (Hoernes & Auinger 1880; Popa et al. 2014); Dacian Basin: Opanec, Târnene (Bulgaria) (Kojumdgieva in Kojumdgieva & Strachimirov 1960).
description: Published as part of Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, pp. 1-72 in Zootaxa 4983 (3) on pages 44-46, DOI: 10.11646/zootaxa.4983.1.1, http://zenodo.org/record/4921887