Nassa thaumasia Sturany, 1900

Albano, Paolo G., Bakker, Piet A. J., Janssen, Ronald & Eschner, Anita, 2017, An illustrated catalogue of Rudolf Sturany's type specimens in the Naturhistorisches Museum Wien, Austria (NHMW): Red Sea gastropods, Zoosystematics and Evolution 93 (1), pp. 45-94 : 63

Nassa thaumasia Sturany, 1900 Figure 17A-E

Nassa thaumasia Sturany, 1900a: 198-199; redescribed and illustrated in Sturany (1903), page 222, plate II, figure 8.

Type locality.

Ras Abu Somer (not specified in the original text, but very likely locality 18, littoral; Table 2 ).

Additional original localities.

94 (314 m) (Northern Red Sea, Table 1 ).

Type material.

Lectotype: NHMW 37579 (locality 18; height 27 mm), fixed by erroneous inference of “holotype” (ICZN art. 74.6) by Cernohorsky 1984: 132, pl. 25 fig. 10. Paralectotype: NHMW 111535: 1 specimen (Ras Abu Somer, likely locality 18).

Additional material.

NHMW 84180 (station 87): 7 specimens.

Original description.

Gehäuse festschalig, aus 10 1/2 langsam zunehmenden, schwach stufig abgesetzten Windungen kegelig aufgebaut; das Embryonalgewinde glatt, die darauffolgenden Umgänge mit breiten Querwülsten und vier bis fünf Spiralreihen ausgestattet, die Schlusswindungen (2 1/2 oder mehr) abgeglättet bis auf eine zur Naht parallel ziehende Spiralfurche und eine Reihe von Spirallinien in der Nabelgegend im Umkreise des Ausschnittes der Mündungsbasis; auf gelblichweißem Grundtone sind gelbbraune Querstriemen in unregelmäßiger und spärlicher Vertheilung und auf dem letzten Umgänge zwei breite, gelbbraune Längsbinden mehr oder minder ausgeprägt; kurz vor dem äußeren Mündungsrand ein dicker Wulst, im Gaumen, sowie auf dem Wulste der Spindel und der Mündungswand eine größere Anzahl von Falten; der untere Theil des äußeren Mündungsrandes etwas ausgezackt.

Höhe der Schale 27,2, Breite 13,0mm; Höhe der Mündung 14,0, Breite 7,5mm. Fundort: Ras Abu Somer (litoral).

Translation.

Shell thick, conical, made of 10.5 slowly growing, weakly scalariform whorls; smooth protoconch, the following whorls have broad axial ribs and four to five spiral threads, the final whorls (two and half or more) smooth except for a groove parallel to the suture and a series of spiral lines in the umbilical region close to the aperture; on the yellowish-white background there are irregularly and sparsely distributed yellow-brown flecks and on the last whorl there are two wide, yellow-brown spiral bands more or less pronounced; shortly before the outer lip there is a thick varix; there is a large number of folds on the callus of the columella and the inner lip; the lower part of the lip is slightly jagged.

Shell height 27.2, width 13.0 mm; height of the mouth 14.0, width 7.5 mm. Locality: Ras Abu Somer (littoral).

Comments.

Nassa steindachneri , thaumasia , thaumasia var. nana and xesta are regarded as synonymous. Nassa thaumasia var. nana and steindachneri occur together at station 94 and both lots show the same variability of sculpture from regularly reticulated to nearly smooth last whorls. Janssen in Janssen and Taviani (2015: 526) used steindachneri as valid name because this is the most common variant, but Dekker and Orlin (2000: 28) synonymised already these taxa and as first revisers selected Nassarius thaumasius (Sturany, 1900) as valid name. Nassa thaumasia was considered by Cernohorsky (1984: 130) as synonym of Nassarius (Zeuxis) castus (Gould, 1850). However, this is most probably wrong, because according to own observations (RJ) thaumasia has a much finer sculpture consisting of dense reticulation, especially on the early whorls, more numerous and finer spiral ribs on the fasciole, only weakly canaliculated sutures and a much lesser developed sutural nodules. Cernohorsky figured the alleged “holotype” of thaumasia on his pl. 25 fig. 10.

According to Cernohorsky (1984: 135), Nassa steindachneri is a synonym of Nassarius (Zeuxis) siquijorensis (A. Adams, 1852). If this proves to be correct, siquijorensis would become the valid name for the assemblage of nominal taxa described by Sturany, but this needs further study.

Figures

Figure 17. Nassa thaumasia Sturany, 1900. A-C, E. Lectotype, NHMW 37579, Ras Abu Somer, Egypt, Red Sea (likely " locality 18 "): front (A), right side (B), back (C), protoconch (E). D. Original figure by Sturany (1903). F. Original lectotype label. G. Original label of the form nana. H-J. Form nana, syntype NHMW 84181, Station 94 (Nuweiba, Gulf of Aqaba, Egypt): front (H), right side (I), back (J). Scale bars: A-C, H-J: 5 mm, E: 0.2 mm.