Replacement names and nomenclatural comments for problematic species-group names in Europe's Neogene freshwater Gastropoda
Author
Neubauer, Thomas A.
Author
Harzhauser, Mathias
Author
Georgopoulou, Elisavet
Author
Mandic, Oleg
Author
Kroh, Andreas
text
Zootaxa
2014
2014-04-04
3785
3
453
468
journal article
5666
10.11646/zootaxa.3785.3.7
8eddca4b-08a5-433a-8e3a-c89fb483818e
1175-5326
4913363
D6E3D055-4390-4DC2-A9AC-0DBC40C2740F
Planorbis varians
Fuchs, 1870
—how to recombine?
Planorbis varians
Fuchs,
1870
in
Fuchs 1870a: 356
, pl. 14, figs 1–9.
Gyraulus (Gyraulus) varians
(Fuchs)
:
Wenz 1923: 1622
(cum syn.).
Muellerpalia varians
(Fuchs, 1870)
;
Bandel 2010: 104
[not pl. 8, figs 90–94, =
Muellerpalia bicincta
(Fuchs, 1870)
].
Marinescugyra
varians
(Fuchs, 1870)
;
Bandel 2010: 112
, pl. 13, figs 153–158.
In his revision about the valvatiform gastropods of the Paratethys realm,
Bandel (2010)
introduced amongst others the genera
Muellerpalia
(Hydrobiidae)
and
Marinescugyra
(
Planorbidae
), based on characteristic protoconch features. One of the discussed species is
Planorbis varians
Fuchs, 1870
from Rădmăneşti in
Romania
. On the grounds of different protoconch properties, Bandel assigned specimens, putatively belonging to the same species, to either
Muellerpalia
(p. 104) or
Marinescugyra
(p. 112). For the latter, it even constitutes the
type
species. Hence, Bandel used two different combinations based on the same original combination.
From a nomenclatural as well as a taxonomic view this is of course not tenable. It means that either the various specimens belong to two different species or the diagnostic features of the two genera are not meaningful. The associated problems were clear to the author as became evident from personal correspondence: Bandel (pers. comm.) stated the possibility that "
Planorbis varians
" is actually represented by two species, which would have to be assigned variably to
Muellerpalia
or
Marinescugyra
based on their protoconchs. Unfortunately, this discussion is wanting in the paper.
However, it turned out that the two combinations indeed refer to different species. The specimens illustrated by
Bandel (2010)
as "
Marinescugyra
varians
" (pl. 13, figs 153–158) undoubtedly refer to the same species as described by
Fuchs (1870a)
. They correspond in the two strong keels, the intermediate spiral lines, the slightly concave umbilical part, and the weakly stepped funnel-like apical part. In contrast, the individuals depicted as "
Muellerpalia varians
" (
Bandel 2010
, pl. 8, figs 90–95) belong to a different species: they have both keels on the umbilical side, apparently lack additional spiral lines, have highly convex whorls, and more distinct growth lines. Direct comparison of the descriptions and illustrations of
Fuchs (1870a
, b) and
Bandel (2010)
suggest that Bandel confused several species. Firstly, "
Muellerpalia varians
" sensu Bandel
rather corresponds to "
Valvata bicincta
Fuchs, 1870
" in
Fuchs (1870b)
[=
Muellerpalia bicincta
(Fuchs, 1870)
]. Secondly, specimens illustrated as "
Muellerpalia bicincta
" by Bandel rather resemble "
Valvata carinata
Fuchs, 1870
" in
Fuchs (1870b)
[=
Muellerpalia carinata
(Fuchs, 1870)
]. Conversely,
Muellerpalia carinata
(Fuchs, 1870) sensu
Bandel, 2010
may represent
Muellerpalia bicincta
. The new combinations of both latter taxa with the new genus
Muellerpalia
still remain valid.
The presence of a second, fainter keel on the umbilical side in "
Muellerpalia varians
" sensu
Bandel (2010)
[=
Muellerpalia bicincta
(Fuchs, 1870)
], which is not discernible in the original material of
Fuchs (1870a)
, is regarded as intraspecific variability herein, as all other features correspond quite well. Unfortunately, Bandel did not provide an illustration of the apical region, which would show a distinct keel if our determination as
M. bicincta
is correct. Nevertheless, the endpoint of keel-like structure is visible in the apertural view (
Bandel 2010
, pl. 8, fig. 94). Even if it might turn out that this tentative placement is wrong, it still remains well separated from
Marinescugyra
varians
.
In conclusion, the genus
Marinescugyra
, with
Planorbis varians
Fuchs, 1870
as
type
species, remains valid and the combination
Marinescugyra
varians
(Fuchs, 1870)
is the only accepted one. The combination
Muellerpalia varians
(Fuchs, 1870)
is based on a misidentification of the species. We tentatively synonymize this record with
Muellerpalia bicincta
(Fuchs, 1870)
.