Strioterebrum Sacco, 1891

Harzhauser, Mathias & Landau, Bernard M., 2023, The auger snails (Gastropoda, Conoidea, Terebridae) of the Miocene Paratethys Sea, Zootaxa 5385 (1), pp. 1-70 : 32-33

Genus Strioterebrum Sacco, 1891

Type species. Terebra basterotii Nyst, 1845 ; original designation by Sacco (1891a: 33); Middle Miocene, North Sea Basin (fixed under ICZN 1999, article 70.3.1.).

Original diagnosis. “ Testa turrita . Anfractus longitudinaliter costulata , transversim striolati, sulco transverso subsuturale (sat profundo) ornati ” [Shell turreted. Whorls axially costulate, transversally striate, and with a spiral groove (deep) ornamented] ( Sacco 1891a: 33).

Revised diagnosis. Medium sized, slender to moderately slender shells with high spire, subcylindrical to weakly convex whorls, and relatively low last whorl. Sculpture of prominent axial ribs with more or less distinctly delimited subsutural band. Groove below subsutural band may be distinct or subobsolete on late teleoconch whorls, forming punctations in the type species. Spiral sculpture of cords or threads appear between axial ribs during ontogeny. Aperture narrow with slightly excavated columella. Siphonal canal moderately long, narrow, twisted.

Discussion. Sacco (1891a) designated Terebra basterotii Nyst, 1845 as type species of Strioterebrum but in fact referred to specimens of Terebra volhyniana d’Orbigny, 1852 . The confusion goes back to Hörnes (1852), who misidentified specimens from the Vienna Basin as Terebra basterotii . At that time, no illustrations of Strioterebrum basterotii from the Middle Miocene of the North Sea Basin have been available, and Hörnes (1852) had to rely on the brief description of Nyst (1845: 582), which just stated spiral striae, which cut the axial ribs (“ stries transverses qui coupent les plis longitudinaux ”). The illustrations in Hörnes (1852), followed by two additional figures in Hoernes & Auinger (1882), distorted the understanding of the North Sea species. Hundred years later, Glibert (1952b; 138) fixed the problem by designating and illustrating a lectotype of Strioterebrum basterotii [I.R.Sc. N.B. 3681 (Institut Royal des Sciences Naturelles de Belgique, Bruxelles); Bolderberg ( Belgium), Middle Miocene, Glibert (1952b: pl. 10, fig. 9)]. The lectotype and specimens illustrated by Glibert (1952a), Janssen (1984) and Wienrich (2006) define Strioterebrum basterotii as having a moderately slender shell with conical spire, conical whorls and a moderately incised groove below the subsutural band. These specimens differ from the Paratethyan shells clearly in their comparatively short spire and a stout outline and lack the slight convexity in the lower third of the whorls. The last whorl attains about 35% of the total height in S. basterotii but only 30% in S. volhynianum (see Glibert, 1952b: pl. 10. fig. 9; Janssen, 1984: pl. 13, fig. 8, pl. 77, figs 1, 2; Wienrich 2006: figs 1/1, 2/1–4).

Prior to Hörnes (1852), the Paratethyan species has been described also by Dubois de Montpéreux (1831: pl. 1, figs 41–42) from the Badenian of Ukraine, who misidentified it with the living Terebra duplicata ( Linnaeus, 1758) . Consequently, d’Orbigny (1852: 88/165) introduced Terebra volhyniana as a new name for this Miocene species. This name has been overlooked or ignored by subsequent authors except for Bronn (1854: 565), who gave a detailed description and correctly included specimens from the Miocene of Austria and Romania in his description.

When discussing Strioterebrum basterotii, Sacco (1891a: 33) clearly referred to the illustration in Hörnes (1852) and complained that the large variability of this species (based on the contradicting literature) would make it difficult to understand the typical ‘form’ (“ a causa della grande variabilità dello S. Basteroti [sic] riesce alquanto incerto il precisarne la forma tipica ”). Sacco (1891a: 34) stated that high and slender shells were typical in his material from the Colli Torinesi (which he compared with the illustrations in Dubois de Montpéreux 1831) but considered smaller and wider specimens illustrated by Hörnes (1852: pl. 11, fig. 27) as typical (“ media grandezza, subconica ”). Thus, Sacco (1891a), by referring to specimen from the Vienna Basin, based his new subgenus Strioterebrum on Terebra volhyniana and not on T. basterotii . For the sake of stability, we apply ICZN 1999, article 70.3.1., which allows us to select and fix as type species the nominal species previously cited as type species.

Synonyms.? Punctoterebra Bartsch, 1923 ; type species Terebra nitida Hinds, 1844 ; present-day, Indo-West Pacific. Strioterebrum , as defined herein, is close to the extant Punctoterebra Bartsch, 1923 Living Punctoterebra species, which are highly reminiscent of Miocene Strioterebrum species are for example Punctoterebra exiguoides ( Schepman, 1913) , P. fuscotaeniata ( Thiele, 1925) , P. lineaperlata ( Terryn & Holford, 2008) , P. livida ( Reeve, 1860) , P. roseata (A. Adams & Reeve, 1850) and P. succincta (Gmelin, 1791) . Therefore, we suggest that Punctoterebra might be a junior synonym of Strioterebrum .

Davoli (1977) and Bouchet (1981) discussed a direct phylogenetic relation of the Miocene Mediterranean Strioterebrum basterotii (non Nyst, 1845) with the Pliocene Strioterebrum pliocenicum (Fontannes, 1881) and the Pliocene and living S. reticulare (Sacco, 1891) , with which we agree (see Terryn & Ryall 2014: pl. 7 for pictures of S. reticulare ).

Fedosov et al. (2020) placed the extant Strioterebrum reticulare in Terebra . This would make, Strioterebrum a subjective junior synonym of Terebra , but this placement was not based on molecular data but only on conchological features (pers com. Alexander Fedosov, 20. 7. 2023). As we consider Strioterebrum reticulare as extant species of Strioterebrum , molecular data of this Eastern Atlantic species could clarify if it is congeneric with the Indo-West Pacific Punctoterebra . [Note that the author of Strioterebrum reticulatum is given as Pecchioli, 1891 in MolluscaBase eds. (2023), but this is a manuscript name, which was made available by Coppi (1881: 40) as ‘ Terebra reticulata Pecc. ’ However, this is a junior homonym of Terebra reticulata J. de C. Sowerby, 1840. Later Sacco (1891a: 40) referred to this species as ‘ Strioterebrum reticulare Pecchioli’. Therefore, we retain the well-known name of S. reticulare with Sacco, 1891 as author].