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
Pyrgo
Defrance 1824
Pyrgo
sp. 1
(
Fig. 12
:12, 13)
Description.
Imperforate, porcelaneous test with inflated chambers separated by very faintly depressed sutures. Test periphery smooth, with weak ‘knife-edge’ margin. Ornament absent. Aperture ovate, subterminal, possessing a wide bifid T-shaped tooth. Aperture boarded by a wide, shallow lip.
Remarks.
These specimens were assigned to
Pyrgo
due to their ovoid test with a slightly angular periphery and adult biloculine chamber arrangement (
Fig. 12
:12, 13). This taxon closely resembles both
Pyrgo denticulata
(
Brady 1884
, pl. 3, fig. 4;
Debenay 2012
, p. 117, pl. 5) and
Pyrgo sarsi
published by
Parker (2009
, fig. 121a–g) in its test form and aperture shape with the hint of a tooth present in some specimens. All the specimens collected from the CG are corroded and damaged making identification below genus level difficult.
Distribution within study area.
Pyrgo
sp. 1 was collected from the Channel sample between Heron and Wistari Reefs and in One Tree Lagoons 2 and 3. Two of the four total specimens collected were from One Tree Lagoon 2.
Pyrgo
sp. 2
(
Fig. 12
:14–16)
Description.
Test elongately oval in outline and cross section. Glossy test walls smooth, apart from very faint, raised longitudinal ridges spaced around test. Periphery rounded with slightly inflated, biloculine chambers. Sutures shallow to almost indistinct. Terminal aperture is very long, thin, almost three times as long as wide. A single tooth extends entire length of aperture, ending in a bifid tip.
Remarks.
This species bears some similarity to the specimens assigned to
Pyrgoella tenuiaperta
(
Huang 1970
)
by
Loeblich & Tappan (1994)
collected from the Timor Sea and Sahul Shelf. However, the specimens reported by
Loeblich & Tappan (1994)
were collected from greater depths, have a much broader test that is less elongate than
Pyrgo
sp. 2, an indistinct apertural lip and a more complex dentition.
Parker (2009)
described
Pyrgo
sp. 1, which is almost identical to
Pyrgo
sp. 2 from the CG, but like the specimens collected by
Loeblich & Tappan (1994)
, the apertural tooth does not extend the entire length of the aperture and ends with a thickened tip rather than a bifurcate one. Parker’s (2009) specimens are also more pinched at the apertural end of the test.
Distribution within study area.
Pyrgo
sp. 2 was only collected from site
40 in
Heron Lagoon.