Early Carboniferous Gastropoda from the Tamworth Belt, New South Wales, Australia
Author
Yoo, E. K.
text
Records of the Australian Museum
1994
1994-05-19
46
1
63
120
https://journals.australian.museum/yoo-1994-rec-aust-mus-461-63120/
journal article
10.3853/j.0067-1975.46.1994.18
b5d2a24f-697a-4fc3-9612-978fb532e815
0067-1975
4654599
Worthenia crenilunula
n.sp.
PI. 8 figs 11-14, PI. 9 figs 5-8
Description. Shell small, turbiniform, heavily ornamented, narrowly phaneromphalous to anomphalous. Protoconch with first whorl seemingly smooth. Teleoconch in 2 distinct layers, the outer layer thin; approximately 5 whorls; suture shallow, whorl profile with strong angulations; selenizone most prominently protruded with upper and lower spiral cords falling just below and above suture, more obtuse; transverse lirae sharp, closely spaced, forming sharp points at the intersection with the protruded selenizone; base with several spiral cords. Selenizone moderately wide, convex, omamented by the same number of pointed lunulae, as collabral lirae. Aperture with inner lip thin, more or less straight, outer lip with a v-shaped sinus culminating at the angulation in a short slit giving rise to a convex, omamented selenizone.
|
Dimensions. H
Holotype
(
F78419
)
6.4 mm
|
W
4.9 mm
|
PA 65° |
NW 5V2 |
|
Paratypes
(
F78413
a)4.5 (
F78415
)4.9 (
F78413
b)6.6
|
3.6 3.9 4.4 |
63 63 60 |
5V2 6 6V2 |
| Dimensions. Figured specimens |
H |
W |
PA |
|
(
F78422
) (
F78423
) (
F78424
)
|
6.6 mm
2.7 3.9
|
5.0 mm 2.1 3.4 |
60° 65 75 |
Types.
Holotype
(
F78419
) and 3 figured
paratypes
(
F78413, F78415
). There are 25 unfigured
additional specimens
(
F78412
) from the type locality.
Type locality. Approximately
250 m
west of Babbinboon Lane, in Swains Gully,
15 km
south-west of Somerton, NSW (Locality 25).
Stratigraphic position. In bioclastic limestone,
130 m
above the base of the Namoi Formation.
Additional material.
7 specimens
from south-east of 'Rangari' (Locality 18) and 1 from Glenbawn (Locality 30).
Geographic distribution. 'Rangari' to Glenbawn.
Geological age. Middle to late Toumaisian.
Etymology. Referring to the prominent crenate lunulae of the selenizone.
Remarks. This species resembles
Ruedemannia
sp. and
Worthenia
sp. (both in this study), but differs from the former in having more conspicuous spiral cords on the whorls including the base, and from the latter in having a taller shell and more narrowly phaneromphalous.