Benthic Foraminifera from the Capricorn Group, Great Barrier Reef, Australia
Author
Mamo, Briony L.
text
Zootaxa
2016
4215
1
1
123
journal article
37169
10.11646/zootaxa.4215.1.1
0087fa4c-a4f0-45d9-a2de-d433d7885753
1175-5326
272923
B91D1782-C11A-4CDC-96B6-76104FEE51BD
Eponides
de
Montfort 1808
Eponides
sp. cf.
E
.
repandus
(
Fichtel & Moll 1798
)
(
Fig. 19
:7–10)
Description.
Test trochospiral, evolute on spiral side and involute on umbilical, unequally biconvex. Periphery smooth, slightly lobulate around weakly inflated chambers with a thin carina. Chambers crescent shaped on spiral side and subtriangular on umbilical side. Sutures radial, curved and depressed on umbilical side, raised on spiral side. Interiosutural area finely perforate to smooth. Clustered pustular ornament occasionally present on initial chambers on both sides of test. Outer edge of final chamber on umbilical side of test extended to form a thin, apertural face pitted with areal apertures.
Remarks.
These specimens are only tentatively assigned to
Eponides repandus
(Fichtel & Moll 1978)
due to the highly damaged nature of the available material however, the distinct features of this species, including the areal apertures on the umbilical side of the test, test shape and ornament (
Fig. 19
:7–10) are apparent.
Eponides repandus
is a common species in reef environments (
Bock
et al.
1971
;
Hatta & Ujiié 1992a
;
Hottinger
et al.
1993
;
Loeblich & Tappan 1994
;
Parker 2009
), but specimens are known to display variation in the test ornament. Some specimens appear to have completely smooth tests (
Hatta & Ujiié 1992a
;
Hottinger
et al.
1993
;
Loeblich & Tappan 1994
) whilst others have more roughened textures due to the presence of fine perforations and their variation in size (
Bock
et al.
1971
;
Parker 2009
;
Debenay 2012
). The location, size and density of the pustulate ornament also varies on the CG specimens and other examples (
Bock
et al.
1971
;
Hatta & Ujiié 1992a
;
Hottinger
et al.
1993
;
Loeblich & Tappan 1994
;
Parker 2009
). Capricorn Group specimens all possessed roughly textured test walls on their aboral sides due to poor preservation and sections of fine perforations divided by imperforate, raised sutures (
Fig. 19
:7, 8). The amount and intensity of pustulate ornament however, varies between CG specimens. Additionally, areal sutures vary in number and proliferation along the apertural face extension with
E. repandus
. Those CG specimens with a relatively large apertural face have areal sutures evenly distributed across the face, similar to the specimens described by
Hatta & Ujiié (1992a)
and
Debenay (2012)
. In contrast, the specimens described by
Parker (2009)
and
Hottinger
et al
. (1993)
have fewer areal apertures with the largest along the periphery of the test. Furthermore, the areal apertures on the specimens illustrated by
Bock
et al
. (1971
, pl. 21, figs 6, 7) and Lobelich &
Tappan (1994
, pl. 268, figs 10–13) are further differentiated by having a number of areal apertures between the two extremes. The apertural face is also angled down sharply back towards the test whereas other examples, like specimens collected from the CG, have only a gently sloping face.
The original description of
E
.
repandus
by
Fichtel & Moll (1798)
is based on material from the Mediterranean Sea. This species has a global distribution (
Florida
Bay—Bock
et al.
1971;
Ryukyu Island
Arc—Hatta &
Ujiié 1992a
;
Gulf
of Aqaba—Hottinger
et al
. 1991a and 1993; northeast Timor Sea from 72 m—Loeblich &
Tappan 1994
; restricted to deeper waters in gaps between reefs at Ningaloo Reef—Parker 2009;
New Caledonia
southern shelf from 30+ m—Debenay 2012).
Distribution within study area.
Eponides repandus
was only found in low abundance (one to six specimens per site) in One Tree lagoons and the channel sample. The site of greatest abundance is site
34 in
One Tree Lagoon 1, which is the centre of the deepest One Tree Lagoon. This distribution matches those previously reported by
Loeblich & Tappan (1994)
and
Parker (2009)
.