Skeneoides Warén, 1992

Haszprunar, Gerhard, Kunze, Thomas, Brückner, Martin & Heß, Martin, 2016, Towards a sound definition of Skeneidae (Mollusca, Vetigastropoda): 3 D interactive anatomy of the type species, Skenea serpuloides (Montagu, 1808) and comments on related taxa, Organisms Diversity & Evolution (New York, N. Y.) 16 (3), pp. 577-595 : 592

Skeneoides Warén, 1992 with type species Delphinola exilissima Philippi, 1844

However, most of these genera need to be studied also anatomically to confirm inclusion. Based on consistent molecular data ( Kano 2008; Williams 2012), we tentatively add here Cirsonella Angas, 1877 (syn. Tharsiella Bush, 1897 ) with type species Cirsonella aostralis Angas, 1877 (currently considered as a synonym of Cyclostrema weldii Tenison-Woods, 1877 ; see Rosenberg 2015), although this should be confirmed by checking the type species for a propodial penis.

Soft part characters of Iheyaspira leqoios ( Okutani et al. 2000) ; the type species of its genus, in particular, a tentaclelike right neck lobe; the separated ESO-tentacle and the lack of a propodial penis ( Okutani et al. 2000; Nye et al. 2013) suggest seguenzioid affinities of Iheyaspira rather than the stated classifications among Trochidae or Skeneidae . The molecular analysis of Nye et al. (2013) inferred Iheyaspira bathycodon in a clade together with Skeneidae , but is not sufficient to prove inclusion, because in particular seguenzioid taxa have not been considered in that study. Most recently, however, Chen et al. (2015) showed that I. leqoios Okutani et al. 2000 is composed of four lineages belonging to both, Vetigastropoda— Skeneidae and Neomphalina.

The record of a propodial penis in Lodderena catenoides by Warén (1992) and thus for Lodderena in general is misleading, because L. catenoides is now accepted as Skenea catenoides (Monterosato, 1877) (WoRMS) . The current data on the type species of Lodderena , L. minima (Tenison-Woods, 1878) , revealed significant differences in the genital system, namely a true hermaphroditic gland, lack of propodial penis and lack of a receptaculum. In addition, molecular data (H3 + COI) group Lodderena with Trochidae / Turbinidae rather than with Skeneidae ( Kano 2008; Williams 2012). Therefore, Lodderena Iredale, 1924 should be excluded from the Skeneidae .

The type species of Leocorhynchia Crosse, 1867, L. caledonica Crosse, 1867 , also shows papillate conditions, but a bipectinate ctenidium, a true hermaphroditic gland with a common gonoduct and a propodial penis on the left side (pers. obs. TK). Accordingly, we also exclude Leocorhynchia Crosse, 1867 from Skeneidae .

For the numerous other genera, which have been assigned to Skeneidae or Skeneinae , molecular or soft part studies (ideally both) are required for in- or exclusion, hard part characters alone clearly are not sufficient, although a protoconch with few spiral cordlets (e.g. Haplocochlias Carpenter, 1864 ; cf. e.g. Rubio & Rolan 2015) raises the probability of inclusion. Representatives of only two genuine skeneid genera with confirmed propodial penis, Dillwynella ( Warén 1992: 152) and Protolira , and the tentatively assigned Cirsonella , were included in molecular analyses ( Table 2).

We cannot exclude the possibility that Skeneidae in the present diagnosis is only a subclade within a broader clade of trochoid vetigastropods which may also include taxa without a propodial penis (or with a left one as in L. caledonica Crossé, 1867 ; Anders Warén pers. comm.). On the other hand, we prefer a clear diagnosis of Skeneidae instead of continuous usage of a family name as a lumping pot for small vetigastropods, which are better assigned as ‘Vetigastropoda incertae sedis ’. Such a diagnosis now is available, and there is little doubt that many skeneid-like species need to be excluded from Skeneidae characterized in this way. This is also a plea to study microgastropods more intensively than up to now. Aside from shell, protoconch and radula, the soft body (by SEM and/ or 3D-morphology) also needs consideration, and ideally molecular data also (see e.g. Chen et al. 2015 as a tale of caution) should be added in order to proceed in our understanding of ‘what [else] is Skeneidae ?’ To conclude, ‘Before we came here we were confused about this subject. Having done our work we are still confused—but on a higher level’ [modified from Enrico Fermi, nuclear physicist] ( Mackey 1991: 90).