Mathilda brusinai de Boury, 1883

Harzhauser, Mathias & Landau, Bernard, 2023, The Architectonicidae and Mathildidae (Gastropoda, Heterobranchia) of the Miocene Paratethys Sea-victims of the Miocene Climatic Transition, Zootaxa 5370 (1), pp. 1-74 : 47-48

Mathilda brusinai de Boury, 1883

Figs 23A 1 –A 3

M [athilda]. Semperi Brusina — Brusina 1877; 17, 385 [non Mathilda semperi Tournouër, 1874 ].

* Mathilda brusinai de Boury 1883: 114 .

Mathilda (M [athilda].) brusinai Boury —Sieber 1958: 139.

Mathilda (Fimbriatella) brusinai Boury —Sieber 1960: 265, pl. 1, figs 28, 30.

Type material. Syntypes: NHMW 1869 /0001/0211, SL: 14 mm, MD: 7 mm, Sedlec (= Porzteich) ( Czech Republic), illustrated in Sieber (1960: pl. 1, figs 28, 30); the specimens seem to be misplaced .

Illustrated material. NHMW 1864/0001/0376, SL: 7.0 mm, MD: 2.4 mm, Jaroměřice ( Czech Republic), Figs 23A 1 –A 3 .

Revised description. Slender turritelliform shell; apical angle ~23–25°. Protoconch

Protoconch multispiral, of about 2.5 smooth whorls, heterostrophic, nucleus fully exposed, tilted at angle of about 140°. Teleoconch of up to ten angled whorls (according to Sieber 1960) with deeply incised, canaliculate suture. First teleoconch whorl S1 weak, S2 strongest forming periphery, S3 slightly weaker placed just above suture, secondary intercalated between S1 and S2 rapidly becoming equal in strength to S1. Second whorl, further secondary cord intercalated between suture and S1. Third whorl secondary intercalated between S2 and S3. All cords overrun by delicate orthocline lamellar ribs forming cancellate surface sculpture with small tubercles developed at intersections. Axial sculpture of numerous delicate axial lamellae forming cancellate surface pattern, with small tubercles developed at intersections. Base with two prominent peribasal cords. Aperture subcircular (based on illustration in Sieber 1960).

Discussion. Brusina (1877) mentioned several specimens in the NHMW collection and Sieber (1960) illustrated one of these syntypes (erroneously labelled as holotype). None of the specimens could be traced in the collection and they seem to have been misplaced. Therefore, the description is based on the sole available specimen from Jaroměřice and partly on the rather poor illustration in Sieber (1960). Mathilda brusinai is reminiscent of M. quadricarinata ( Brocchi, 1814) and both have a prominent secondary cord of the subsutural ramp. Both species differ in that M. brusinae has a less strongly tilted protoconch, a deeper suture, and the secondary cords are intercalated earlier in ontogeny. Mathilda brocchii Semper, 1865 , from the Pliocene Mediterranean, as illustrated by Tabanelli et al. (2021), differs in its broader outline and the much more prominent mid-whorl keel. Mathilda granosa ( Borson, 1821) lacks the fourth spiral cord (see Pavia 1976: pl. 1, figs 2a–2b; Landau et al. 2013: 303, pl. 52, fig. 4).

Paleoecology. Unknown

Distribution. Middle Miocene of the Central Paratethys Sea.

Central Paratethys Sea. Badenian (Middle Miocene): North Alpine-Carpathian Foredeep: Jaroměřice ( Czech Republic) (hoc opus); Vienna Basin: Sedlec (= Porzteich) ( Czech Republic) (Sieber 1960).

Figures

FIGURE 1. Descriptive terms used in descriptions of Architectonicidae (modified from Bieler 1993).

FIGURE 3. Descriptive terms used in descriptions of Mathildidae.

FIGURE 23 A1–A3. Mathilda brusinai de Boury, 1883, NHMW 1864/0001/0376, Jaroměřice (Czech Republic).