A new genus and eight new species of tail-wagger snails from eastern South Africa, with a key to genera within Sheldonia s. l. (Gastropoda: Urocyclidae)
Author
Herbert, David G.
text
European Journal of Taxonomy
2017
2017-04-10
309
1
50
journal article
22144
10.5852/ejt.2017.309
4e7bcd4d-1cdb-45cf-b2c3-54da2466f171
2118-9773
3827189
1E8FE779-D6E7-428E-9538-5E5F8ECFB271
Key to genera within
Sheldonia
s.l
.
1. Epiphallic caecum arising close to penis apex and adjacent to insertion of penial retractor muscle (
Fig. 1A
) ……………………………………………………………………………………………2
– Epiphallic caecum arising nearer to mid-point of epiphallus (
Fig. 1
B–C) …………………………3
2. Flagellum short and stout (
Fig. 1D
); epiphallus short; vas deferens thick, long and convoluted; spermatophore tail plumose (
Fig. 1E
);protoconch spirally punctate ………
Ptilototheca
Herbert, 2016
– Flagellum longer, divided into distinct f1 and f2 components (
Fig. 1A
); vas deferens slender and relatively short, not convoluted; spermatophore tail with branched spines (
Fig. 1F
), but not plumose; protoconch smooth (rarely spirally lirate), not punctate. ………
Kerkophorus
Godwin-Austen, 1912
3. Epiphallic caecum small and globular (
Fig. 1B
); spermatophore tail bifid (
Fig. 1G
) ……………… …………………………………………………………………
Microkerkus
Godwin-Austen, 1912
– Epiphallic caecum large, cylindrical and usually curved (
Fig. 1C
); spermatophore tail not bifid …4
4. Protoconch spirally punctate or with numerous, close-set, incised spiral microstriae; nonspinose distal portion of spermatophore tail long, the subterminal region with short, stout projections on both sides (
Fig. 1H
, inset) ……………………………
Sheldonia
s.s.
Ancey, 1887
– Protoconch essentially smooth; non-spinose distal portion of spermatophore tail short, lacking lateral projections (
Fig. 1I
, arrow) …………………………………………
Selatodryas
gen. nov.
This key must be considered provisional and is provided as a guide to the identification of the existing supra-specific taxa within
Sheldonia
s.l.
However, there remain taxa within
Sheldonia
s.l
.
that do not fit well into any of these taxa (e.g.,
Sheldonia monsmaripi
Herbert, 2016
and
S. wolkbergensis
Herbert, 2016
). Establishing the true relationships of these enigmatic species will require additional insights from molecular data. Furthermore, even within these genera, there is significant variation and future research may reveal that this encompasses additional lineages worthy of recognition as distinct genera, particularly within
Kerkophorus
and
Microkerkus
. Construction of a key should thus be viewed as an iterative process, for which this is a first step.