Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil
Author
Figueira, Raquel Medeiros Andrade
Author
Absalão, Ricardo Silva
text
Zootaxa
2012
3527
1
27
journal article
10.5281/zenodo.210977
8eba0512-d65c-4c36-8c30-6d629fabfff8
1175-5326
210977
Genus
Magnella
Dittmer, 1960
Type
species:
Magnella andersoni
Dittmer, 1960
, by original designation.
Remarks
: This genus resembles
Gymnobela
in the plump profile, short spire and short anterior siphonal canal. However, according to the original descriptions and
type
species (
Dittmer, 1960
;
Verrill, 1884
),
Magnella
is characterized by the presence of a strong subsutural spiral cord, whereas in
Gymnobela
a subsutural cord is not present or it is very faint. Besides,
Magnella
does not have the strong shoulder that characterizes
Gymnobela
,
and it has a shallower anal sinus. Maxwell (1988)
apud
Kilburn (1991)
proposed that
Magnella
should be considered a synonym of
Mioawateria
Vella, 1954
. Like Maxwell,
Sysoev (1997)
also assumed that the protoconch in the later genus is diagonally cancelled. That assumption can not be confirmed, as the
type
material of
Mioawateria personata
(
Powell, 1942: 130, pl. 11, fig. 3
), the
type
species of the genus, has a broken protoconch; and in the same paper as the original description of
Mioawateria
(
Vella, 1954: 552
)
the author placed other species with smooth, blunt protoconchs in this genus. Therefore, there are no objective elements to sustain the synonymy between
Magnella
and
Mioawateria
. Besides,
M. personata
has a much stronger shoulder and a much more delicate subsutural cord, being closer to
Gymnobela
in general shape.