Tomellana aueri, Harzhauser & Landau & Janssen, 2022

Harzhauser, Mathias, Landau, Bernard & Janssen, Ronald, 2022, The Clavatulidae (Gastropoda, Conoidea) of the Miocene Paratethys Sea with considerations on fossil and extant Clavatulidae genera, Zootaxa 5123 (1), pp. 1-172 : 143-144

Genus Tomellana Wenz, 1943

Type species. Clavatula lineata Lamarck, 1816 , by typification of replaced name; present-day, West Africa .

Note. This genus was established as Tomella by Swainson, (1840: 314) (type species Clavatula lineata Lamarck, 1816 by subsequent designation by Herrmannsen (1849: 579), which was a junior homonym of Tomella RobineauDesvoidy, 1830 [ Diptera ]. Therefore, Wenz (1943: 1383) introduced Tomellana as replacement name.

Diagnosis. ‘ differs from Perrona in its short, concavely outlined spire, massive peripheral fold, lack of a basal angulation, very heavy parietal callus pad, and deep slit-like anal sinus. Protoconch small, papillate of 1.5 smooth whorls, followed by a whorl of sigmoid brephic axials. … The anal fasciole does not show on the spire whorls, being immersed by each succeeding whorl. Parietal callus pad white, very massive.” ( Powell 1966: 56).

Included species. Central Paratethys Sea: Pleurotoma (Perrona) semimarginata praecursor Schaffer, 1912 , Tomellana aueri nov. sp., Tomellana dulai nov. sp.

Proto-Mediterraean Sea:? Clavatula (Perrona) semimarginata var. servata Sacco, 1890 , an additional species from the Pliocene of Estepona ( Spain) will be described by Landau & Harzhauser (2022).

Norteastern Atlantic: Pleurotoma jouannetii Des Moulins, 1842 , Pleurotoma semimarginata Lamarck, 1822 , Perrona jouanneti [sic] sensu Landau et al., 2011 and sensu Vera-Peláez, 2001 (non Des Moulins, 1842), an additional species from the Pliocene of Huleva ( Spain) will be described by Landau & Harzhauser (2022).

West Africa (Recent): Tomella hupferi Strebel, 1912 , Tomella leschkei Strebel, 1912 .

Clavatula lineata Lamarck, 1816 ,

Stratigraphic and geographic range. Central Paratethys Sea: early to middle Miocene (Eggenburgian to Badenian, late Burdigalian to Langhian), Austria, Germany, Hungary, Romania; (Proto-)Mediterranean Sea:? late Miocene (Tortonian), Italy. Pliocene: Spain (Landau et al. in prep); northeastern Atlantic: early Miocene (Burdigalian): France; present-day: West Africa, upper Pliocene, southwestern Spain ( Landau et al. 2011).

Discussion. Powell (1966, p. 56) considered Tomellana Wenz, 1943 monotypic but MolluscaBase (Eds.) (2021d) includes also Tomellana hupferi ( Strebel, 1912) and Tomellana leschkei ( Strebel, 1912) in this genus. Including these species documents that the callus pad of the type species is extraordinarily thickened and that this feature is not indicative for the genus. If the early whorls are used to characterize the genus then Tomellana is characterized by “ Falten …, die der Anwuchsrichtung folgend, geschweift sind, anfangs sich über die ganze Windung erstrecken, dann oben obsolet werden und schliesslich in kurze schräge Falten oberhalb der Naht auslaufen, die aber je nach der Art nur zwischen der zweiten uns siebenten Windung auftreten ” [by sigmoidal folds, which initially follow the growth lines across the entire whorl but become adapically obsolete and grade into short, oblique folds above the suture, which depending on species, appear only between the second and seventh whorl] Strebel (1912: 5). In addition, we observe a distinct, but narrow subsutural spiral cord on early teleoconch whorls of Tomellana .

Later teleoconch whorls bear a weakly carinate subsutural cord some distance from the suture. This feature is typically developed in T. hupferi and T. hupferi fusca ( Strebel, 1912) (see Nolf 2015: pl. 9), and in T. leschkei ( Strebel, 1912) (see Nolf 2015: pl. 12), but rarely also seen in T. lineata gracilis ( Strebel, 1912) ( Nolf 2015: pl. 8). Perrona , as understood herein, has opisthocline, comma-shaped axial riblets between two adsutural spiral cords ( Strebel 1912), whereas Tomellana has a beaded suprasutural spiral cord. The siphonal canal of Tomellana is much longer and its spire is conical as opposed to slightly gradate in most Perrona species. The separation of Tomellana from Perrona is also supported by molecular data (N. Puillandre, pers. comm., October 2021), corroborating our interpretation of the systematic value of early teleoconch whorl sculpture in Clavatulidae .

So far, this genus was only known from recent species from West Africa ( Strebel, 1912; Nolf, 2015). Based on the early teleoconch morphology and overall shape, we assume that Miocene representatives of Tomellana might have been overlooked so far by placing the species in Perrona . An emblematic example is Pleurotoma jouannetii Des Moulins, 1842 , from the Burdigalian of Mérignac in France, which was placed in Perrona by all authors since Peyrot (1931). We did not study topotypic specimens of this species from Mérignac, but the early whorls of specimens from the Burdigalian of Léognan ( France, NHMW 1858/0018/0104) ( Fig. 43 ), differ greatly from that of typical Perrona , which has short, comma-shaped riblets between two narrow adsutural spiral cords, but agrees well with that of extant Tomellana species.

Pusionella Gray, 1847 differs distinctly in its wide and very shallow anal canal. The extant Pusionella kraepelini Strebel, 1914 , from Angola and Gabon, is reminiscent in general shape and bears beads at the abapical suture ( Strebel 1914; Bernard 1984), but has a shallow anal sinus as typical for Pusionella .

Paleoenvironment. The fossil species derive from inner neritic environments. Present-day species are reported from soft bottom environments in 7 to 50 m water depth ( Nolf 2015).

Figures

FIGURE 43 A1–A3. Tomellana jouannetii (Des Moulins, 1842), NHMW 1858/0018/0104, Mérignac (France), Burdigalian.