Heliacus miser
Creators: name: Harzhauser, Mathias
name: Landau, Bernard
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Heterostropha
Architectonicidae
Heliacus
Heliacus miser

description: Heliacus miser (Dujardin, 1837)
Figs 4M, 15A–D
* Solarium miserum Duj. — Dujardin 1837: 284, pl. 19 fig. 11.
Solarium (Torinia) albertinae Sacco —Boettger 1907: 137 [non Heliacus albertinae (Sacco, 1892)].
Solarium (Pseudotorinia) miserum Dujardin, 1837 — Glibert 1949: 124, pl. 7, fugs 7a–c.
Pseudotorinia obtusa Bronn —Strausz 1954: 15, pl. 6, fig. 141 [non Pseudotorinia obtusa (Bronn, 1831)].
Solarium (Pseudotorinia) obtusa Bronn —Strausz 1966: 119, pl. 51, figs 2–4 [non Pseudotorinia obtusa (Bronn, 1831)].
Solarium berthae Bttgr. — Csepreghy-Meznerics 1969a: 69, pl. 1, figs 11, 14 [non Pseudotorinia berthae (Boettger, 1902))].
Solarium berthae Boettger — Csepreghy-Meznerics 1969b: 20, pl. 2, figs 16, 20, 24 [non Pseudotorinia berthae (Boettger, 1902))].
Architectonica (Pseudotorinia) misera berthae (Boettger, 1901) — Bałuk 1975: 118, pl. 13, figs 7–8 [non Pseudotorinia berthae (Boettger, 1902)].
Architectonica (Pseudotorinia) misera (Dujardin, 1837) — Bałuk 2006: 195: pl. 7, fig. 5.
? Heliacus bisulcatus (d’Orbigny, 1842) — Katona et al. 2011: 15 [non d’Orbigny, 1842].
Heliacus (Torinista) miser (Dujardin, 1837) — Ceulemans et al. 2018: 115, pl. 6, fig. 12.
non Solarium (Pseudotorinia) miserum Dujardin — Cossmann & Peyrot 1919: 472, pl. 15, figs 62–64.
Type material. The whereabouts of the material published by Dujardin (1837) is unclear and most probably lost. Félix Dujardin (1801–1860) had been working in Rennes, but no collection is preserved at the University of Rennes (pers. comm. Damien Gendry, Université de Rennes, France). Dujardin frequently visited the Natural History Museum in Tours and in 1830, he deposited material there (“ Les débris de végétaux et de coquilles seront déposés au cabinet de minéralogie de la ville ” Ribellerie 1830: 93). It is possible that the material on which his 1837 publication was based was given to Tours as well, as Dujardin was curator at the museum for a short period. During World War II, the museum in Tours and its collections were completely destroyed (Didier Lastu, Muséum de Tours, pers. comm. 12. 7. 2023). Material from the Touraine was sent by Dujardin also to various colleagues (e.g., de Roys et al. 1839: 321). Lyell (1839: 205) explicitly stated that he had received material from Dujardin’s 1837 -monograph. This material could not be traced either. [For biographic data on Dujardin see Rideau (2010)].
Illustrated material. NHMW 2023 /0267/0001, SL: 3.3 mm, MD: 7.3 mm, Steinebrunn (Austria), Figs 4M, 15A 1 –A 3. NHMW 2023 /0267/0002, SL: 3.3 mm, MD: 5.6 m, Steinebrunn (Austria), Figs 15B 1 –B 3. NHMW 2023 /0267/0003, SL: 3.6 mm, MD: 7.8 mm, Steinebrunn (Austria), Figs 15C 1 –C 3. NHMW 2023 /0267/0004, SL: 4.8 mm, MD: 6.2 mm, Steinebrunn (Austria), Figs 15D 1 –D 3.
Additional material. NHMW 2023 /0267/0005, SL: 3.5 mm, MD: 7.5 mm, Steinebrunn (Austria); 4 spec., NHMW 2023 /0267/0006, Steinebrunn (Austria); 8 spec., NHMW 1866 /0001/0926, Niederleis (Austria).
Revised description. Small, solid shell with moderately elevated conical spire and angulated periphery. Protoconch heterostrophic, medium-sized of 1.2 visible whorls (diameter 1.0 mm). Teleoconch of 3.5 weakly convex whorls. First teleoconch whorl with SSC, UPC and LPC with coarse, axially arranged beads. One weaker, beaded MC intercalated on second whorl, bifurcating on subsequent whorl. Additional narrow, beaded cord intercalated between UPC and LPC on last whorl (cord may be subobsolete in some specimens). Periphery with rounded keel formed by LPC; second, slightly weaker keel formed by IPC just below. Delicate, beaded spiral thread intercalated between keels. Base faintly concave below IPC, weakly convex below. Basal field with three flat spiral cords with subquadratic beads, widening towards umbilicus. Two narrow spiral threads intercalated between IPC and two adperipheral cords. PUC slightly wider with prominent subquadratic beads, separated from UC by narrow groove. UC prominent, tubercular, overhanging umbilicus. Umbilicus cylindrical, wide (~26–32% of total diameter). Umbilical wall with prominent, weakly prosocline growth lines and central spiral cord. Aperture subcircular with weak CG. PG not developed.
Discussion. This species was placed in Pseudotorinia by several authors, but the morphology with two keels suggests a placement in Heliacus, which was also proposed by Mollusca Base eds. (2021). Although the Middle Miocene faunas of the Northeastern Atlantic and the Central Paratethys Sea have few species in common, Heliacus miser seems to represent one of these rare cases. Specimens from the Middle Miocene and Pliocene of the Loire Basin (France) differ only in the slightly more delicate spiral cords on the basal field and tend to form a broader spiral cord next to the PUC with more and axially elongated beads, whereas these beads are subquadratic in Paratethyan specimens. We refrain from separating these morphs based on such vague features. Heliacus miser sensu Cossmann & Peyrot, 1919 from the Serravallian of the Northeastern Atlantic, differs in its much more delicate and regular spiral cords of small beads and the comparatively less angulated lower periphery (Cossmann & Peyrot 1919: 472, pl. 15, figs 62–64; https://science.mnhn.fr/institution/mnhn/collection/f/item/j12380?lang=en_ US).
The extant to Miocene Heliacus fallaciosus (Tiberi, 1872) [= Heliacus subvariegatus (d’Orbigny, 1852)] differs in its larger size and much more delicate sculpture on both spire and base (e.g., Bogi et al. 2002; figs 14–15; Chirli 2013: pl. 5, figs 7–12;). Heliacus faustae (Sacco, 1892), from the Burdigalian of the Colli Torinesi (Italy), develops large beads on the basal field and a weaker IPC (Sacco 1892: pl. 2, fig. 56; Ferrero Mortara et al. 1984: pl. 15, figs 5a–c). Heliacus albertinae (Sacco, 1892), from the Burdigalian and Langhian of the Colli Torinesi (Italy), is much larger and has more delicate sculpture (see Sacco 1892: pl. 2, figs 60–64; Ferrero Mortara et al. 1984: pl. 15, figs 3a–c).
Paleoenvironment. The occurrence at Steinebrunn (Austria) is indicative for inner neritic environments with sea grass (own data M.H.).
Distribution. Known from the Langhian equivalent of the Badenian in the Central Paratethys Sea and from the Middle Miocene to Early Pliocene in the Northeastern Atlantic.
Northeastern Atlantic. Middle Miocene: Aquitaine Basin (France) (Cossmann & Peyrot 1919), Loire Basin (France) (Glibert 1949). Lower Pliocene: Loire Basin (France) (Ceulemans et al. 2018).
Central Paratethys Sea. Badenian (Middle Miocene): Korytnica Basin: Korytnica (Poland) (Bałuk 2006); Vienna Basin: Steinebrunn (Austria); B̧kk Mountains: Sámsonháza (Hungary) (Csepreghy-Meznerics 1969a, 1969b), Várpalota (Hungary) (Strausz 1954); Făget Basin: Coşteiu de Sus (Romania) (Boettger 1907).
description: Published as part of Harzhauser, Mathias & Landau, Bernard, 2023, The Architectonicidae and Mathildidae (Gastropoda, Heterobranchia) of the Miocene Paratethys Sea-victims of the Miocene Climatic Transition, pp. 1-74 in Zootaxa 5370 (1) on pages 30-31, DOI: 10.11646/zootaxa.5370.1.1, http://zenodo.org/record/10147814