The Columbellidae (Gastropoda, Buccinoidea) in the Miocene Paratethys Sea — striking diversity of a negelected group
Author
Harzhauser, Mathias
0000-0002-4471-6655
mathias.harzhauser@nhm-wien.ac.at
Author
Landau, Bernard M.
0000-0002-4471-6655
mathias.harzhauser@nhm-wien.ac.at
text
Zootaxa
2021
2021-08-23
5025
1
1
75
http://dx.doi.org/10.11646/zootaxa.5025.1.1
journal article
10.11646/zootaxa.5025.1.1
1175-5326
5258835
35E6C8FA-4078-4C53-9B74-F9618D5E6E60
Mitrella pseudofallax
(
Kókay, 1966
)
nov. comb.
Figs 10A
1
–A
2
Pyrene
(
Anachis
)
pseudofallax
nov. sp.
—
Kókay 1966: 58
, pl. 8, fig. 8.
Type material.
Holotype
:
Museum
of the
Mining
and
Geological Survey
of
Hungary
(
Budapest
), M.2539 (= M. 282, old inventory number),
Márkó
(
Hungary
),
Figs 10A
1
–A
2
.
Description.
Shell small, moderately broad fusiform, with high conical spire and weakly incised suture. Protoconch low conical, paucispiral of about two whorls. Spire whorls almost flat-sided, smooth. Last whorl high, flat sided in adapical third, moderately convex below, slowly contracting at base, bearing sculpture of broad, convex, orthocline axial swellings restricted to first half of last whorl, weak spiral cords on siphonal fasciole. Aperture moderately narrow. Outer lip incomplete, but pinched inwards at level of D1, with inner labial callus pad, bearing about ten prominent denticles within; D1 strongest. Anal canal narrowly U-shaped. Siphonal canal short, wide. Columellar callus moderately thickened forming narrow callus rim, with five weak columellar denticles. Parietal callus weakly thickened. Colour pattern of small close set white dots covering entire shell.
Shell measurements and ratios.
SL: 6.0 mm, MD:
2.4 mm
, AA: 37°, SL/MD: 2.7, AL/AW: 3.7, LWH/AH: 1.4.
Discussion.
We are not aware of any similar species in the European Neogene. The narrow aperture and the Ushaped anal canal, which is narrowed by a prominent D1 denticle, exclude a placement in
Costoanachis
as understood herein.
Kókay (1966)
discussed a similarity with
Mitrella fallax
Hoernes & Auinger, 1880
. Both species, however, have little in common and
Mitrella fallax
differs obviously in its higher spire, convex and strongly constricted last whorl and presence of a varix-like swelling close to the aperture.
FIGURE 10 A
1
–A
2
.
Mitrella pseudofallax
(
Kókay, 1966
)
, M.2539, holotype, Márkó (Hungary).
Mitrella pseudofallax
(
Kókay, 1966
)
is superficially reminiscent of
Pardalinops
deMaintenon, 2008
(
type
species
Colombella pardalina
Lamarck, 1822
[=
Pardalinops testudinaria
(
Link, 1807
)
]). The Miocene species agrees with extant
Pardalinops
species
, such as
Pardalinops testudinaria
(
Link, 1807
)
and
Pardalinops jousseaumei
(
Drivas & Jay, 1997
)
, in the absence of axial sculpture, the close set denticles, which cover the entire outer lip, the central swelling of the outer lip, the U-shaped anal canal and the colour pattern of white dots. Nevertheless, the Miocene species differs from extant
Pardalinops
species
in its higher spire, more slender outline and its relatively small size of only
6 mm
height, whereas extant
Pardalinops
species
range between 9 and
17 mm
(
deMaintenon 2008
).
Mitrella pseudofallax
is documented from coastal mudflats (
Kókay 1966
).
The Miocene species is reminiscent of the IWP genus
Zafra
A.
Adams, 1860
(
type
species
Zafra mitriformis
A.
Adams, 1860
). DeMaintenon (2018: 361) stressed a narrow (but not slit-like) aperture and a thickened outer lip with marked central swelling, resulting in narrowly U-shaped anal canal as typical for
Zafra
.
Zafra brunneastriata
K. Monsecour & D.
Monsecour, 2018
, from
French Polynesia
, is a morphologically very similar extant species concerning the elongate outline and the peculiar axial sculpture of the last whorl. Nevertheless, a placement in
Zafra
is excluded based on the absence of axial sculpture on early teleoconch whorls.
Palaeoenvironment.
Coastal mudflats;
Kókay (1966)
described this species from a potamidid-dominated assemblage.
Distribution in Central Paratethys.
Badenian (middle Miocene):
Pannonian Basin
: Márkó (
Hungary
) (
Kókay 1966
).