Revision of Dadagulella gen. nov., the “ Gulella radius group ” (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies
Author
Rowson, Ben
05D46259-DA45-45A4-9127-5AF361D566A7
Biodiversity & Systematic Biology, National Museum of Wales, Cathays Park, Cardiff, UK CF 10 3 NP. Email: ben. rowson @ museumwales. ac. uk & urn: lsid: zoobank. org: author: 05 D 46259 - DA 45 - 45 A 4 - 9127 - 5 AF 361 D 566 A 7
Author
Tattersfield, Peter
8C55642E-B18A-461B-9BF9-31CB6DB7A070
Biodiversity & Systematic Biology, National Museum of Wales, Cathays Park, Cardiff, UK CF 10 3 NP. Email: ben. rowson @ museumwales. ac. uk & urn: lsid: zoobank. org: author: 8 C 55642 E-B 18 A- 461 B- 9 BF 9 - 31 CB 6 DB 7 A 070
text
European Journal of Taxonomy
2013
2013-02-04
37
1
46
journal article
http://dx.doi.org/10.5852/ejt.2013.37
9682b45b-5e22-4965-a293-e203660e0ed3
2118-9773
3806770
ADF6394E-77B5-4309-87FE-4097FDE0A3FD
Dadagulella browni mafiensis
subsp. nov.
Figs 21
,
54
,
84
;
Table 1
Etymology
From Mafia Island, with the final ‘a’ elided for euphony.
Type
material examined
NHMUK
.20110174:
1 ad.
, Mlula, Mafia
I
. (approx.
7.87°
S
,
39.76°
E
), evergreen coastal thicket on clay loam coral rag, leg. Frontier
Tanzania
,
Oct.-
Nov.
1990
, labelled “
Gulella
radius
aggreg.” by
B
. Verdcourt.
Other material examined
None.
Description
SHELL
(
Figs 21
,
54
). Small (
3.30 mm
high x
1.80 mm
wide), of 6.0 whorls. Ovate-acuminate, spire broadly acuminate (spire angle 65°). Apex conical. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (12 per mm on penultimate whorl). Sutures relatively shallow. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition 5-fold, consisting of: one lamella-like parietal tooth and one additional parietal denticle; one slab-like palatal tooth, forming a narrow parieto-palatal sinus; one basal denticle; and a deep-set, folded columellar baffle, but no shallower columellar denticles. Shells and anatomy of juveniles unknown.
Range and habitat
Evergreen coastal thicket at the
type
locality.
Remarks
This taxon is in some respects intermediate between the
type
specimens of
D. r. radius
comb. nov.
and
D. b.
browni
comb. nov.
, and thus distinct from either, yet difficult to place. It is larger and not as squat as other
D. browni
comb. nov.
s.l.
, and lacks the additional basal denticle and shallower columellar dentition. Conversely, it has a parietal denticle not seen in
D. radius
comb. nov.
s.l, is smaller and squatter than most
D. radius
comb. nov.
s.l.
, and has a longer and narrower parieto-palatal sinus than any
D. radius
comb. nov.
s.l.
Mafia Island, from which no other
Dadagulella
gen. nov.
are yet known, lies at almost the same latitude (
7.8°
S
) as the apparent northernmost limit of
D. b.
browni
comb. nov.
in mainland
Tanzania
. Given the morphology of this specimen, its latitude and its isolation as an island population, we treat it as a subspecies of
D. browni
comb. nov.