Mathilda monilis Semper, 1865

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 : 52-53

publication ID	https://doi.org/ 10.11646/zootaxa.5370.1.1
publication LSID	lsid:zoobank.org:pub:48903495-7C6C-46E4-9B1B-D6A2F2781873
DOI	https://doi.org/10.5281/zenodo.10580824
persistent identifier	https://treatment.plazi.org/id/03BEE17B-FFF2-C050-FF0E-FF657CE237C0
treatment provided by	Plazi
scientific name	Mathilda monilis Semper, 1865
status

Treatment

Mathilda monilis Semper, 1865 View in CoL

Figs 26A–D View FIGURE 26

* Mathilda monilis O. Semper — Semper 1865: 344, pl. 13, fig. 6.

Mathilda monilis O. Semper View in CoL — de Boury 1883: 118.

Mathilda monilis O. Semp. View in CoL — Boettger 1902: 155.

non Mathilda monilis Semper, 1865 View in CoL — Bałuk 2006: 196: pl. 7, fig. 3 [= Mathilda margaritula Semper, 1865 ].

Type material. Lectotype (designated herein): NHMW 1858 View Materials /0047/0039, SL: 4.7 mm, MD: 2.2 mm, Sedlec (= Porzteich) ( Czech Republic), Fig. 26C View FIGURE 26 . Paralectotypes: NHMW 2023 View Materials /0270/0001, SL: 4.5 mm, MD: 2.0 mm, Sedlec (= Porzteich) ( Czech Republic), Figs 26B View FIGURE 26 1 –B View FIGURE 1 2 View FIGURE 2 . NHMW 2023 View Materials /0270/0002, SL: 3.6 mm, MD: 1.7 mm, Sedlec (= Porzteich) ( Czech Republic), Fig. 26D View FIGURE 26 .

Illustrated material. NHMW 1869/0013/0020, SL: 3.0 mm, MD: 1.6 mm, Coşteiu de Sus ( Romania), Fig. 26A View FIGURE 26 .

Additional material. 2 spec., NHMW 1876 View Materials /9911/0097, Lăpugiu des Sus ( Romania) .

Revised description. Small, robust, stout, conical, shell; apical angle ~31–33°. Protoconch multispiral, of about 2.5 smooth whorls, heterostrophic, nucleus not exposed, tilted at angle of about 115°. Teleoconch of at least six straight sided whorls with narrowly incised suture. Sculpture of three primary spiral cords of roughly equal strength separated by narrower interspaces; S1 slightly recessed; interspace between S1 and S2 slightly wider; S3 forming periphery. Axial sculpture of about 25 weak, slightly prosocline axial ribs with prominent rounded tubercles formed at intersections almost touching. Last whorl damaged in all available specimens.

Discussion. This species is characterized by its broad conical shape and straight-sided whorls with densely tuberculate sculpture. It is also unusual in having the whorl periphery at S3 rather than S2. Mathilda margaritula Semper, 1865 is much slenderer and differs in its cancellate sculpture. A paratype of Mathilda peyroti Cossmann & Peyrot, 1922 (MNHN.F.J05877), from the Aquitanian of France, is similar to M. monilis in its sculpture but is finer and has a more prominent mid-whorl cord (see https://science.mnhn.fr/institution/mnhn/collection/f/item/j05877?li stIndex=9&listCount=26). Among the extant Mediterraean fauna, Mathilda retusa Brugnone, 1873 is most similar to M. monilis but S1 is more recessed in M. retusa and its suture is more deeply incised.

Paleoecology. Unknown; probably middle to outer neritic.

Distribution. Only known from the Langhian equivalent of the Badenian in the Sea.

Central Paratethys Sea. Middle Miocene (Badenian): North Alpine Carpathian Foreland Basin: Sedlec (= Porzteich) ( Czech Republic) (hoc opus); Făget Basin: Coşteiu de Sus, Lăpugiu de Sus (Semper 1865; Boettger 1902).