“ Larger ” Benthic Foraminifera Of The Cenomanian. A Review Of The Identity And The Stratigraphic And Palaeogeographic Distribution Of Non-Fusiform Planispiral (Or Near-Planispiral) Forms
Author
SIMMONS, MICHAEL
Halliburton, 97 Milton Park, Abingdon, OX 14 4 RW, UK & The Natural History Museum, Cromwell Road, London, SW 7 5 BD, UK
mike.simmons@halliburton.com
Author
BIDGOOD, MICHAEL
GSS Geoscience Ltd., 2 Meadows Drive, Oldmeldrum, AB 51 0 GA, UK
mike@gssgeoscience.co.uk
text
Acta Palaeontologica Romaniae
2023
2023-08-02
19
2
39
169
http://dx.doi.org/10.35463/j.apr.2023.02.06
journal article
10.35463/j.apr.2023.02.06
1842-371x
10834181
Pseudocyclammina rugosa
(
d’Orbigny, 1850
)
Reference Illustration & Description
Maync (1952)
, Pl. 12, figs. 6-10, p. 50 and
Maync (1959a)
, Pl. 1, figs. 10-15.
Pseudocyclammina
is a well-established genus, occurring throughout the Jurassic and Cretaceous, and well known from its
type
species,
P. lituus
, which can be common in suitable Late Jurassic and Early Cretaceous facies from a number of locations across Tethys (e.g.,
Maync, 1959a
;
Banner, 1970
;
Kobayashi & Vuks, 2006
). The test of
Pseudocyclammina
is typically a subspherical planispire, with relatively thick alveolar walls and septa. There is often an uncoiled stage. The aperture is cribrate (which distinguishes it from
Buccicrenata
).
Pseudocyclammina
typically lacks the rapidly enlarging chambers and lobate equatorial profile of
Buccicrenata
. The alveoles are broad and less crowded than in
Choffatella
and similar genera.
The typical Cenomanian representative of the genus is
P. rugosa
,
that despite illustration by
Maync (1952
,
1959a
) remains poorly known.
Lituola rugosa
was introduced by
d’Orbigny (1850)
with a very short entry in a list of Cenomanian foraminifera, and there is no illustration.
Maync (1952
,
1959a
) illustrated
topotype
specimens from the Cenomanian of Charente,
France
(see also
BouDagher-Fadel et al., 2017
) and discussed elements of the taxonomy (including his justification for placing the species in
Pseudocyclammina
) and differences with similar taxa.
P. rugosa
appears to be relatively large (
0.8 – 4.3 mm
in external diameter of the coiled whorl according to
Maync (1959a)
although illustrations in
Maync (1952
,
1959a
) indicate maximum diameter, including uncoiled to be 4.78 – 6.0 mm) and this, together with a large chamber height, strongly curved thick septa, a rounded periphery, a relatively large axial thickness (
0.7-2.3 mm
) (diameter – thickness ratio 1 – 1.9, typically 1.4) and 5-7 chambers in the last whorl serve to distinguish it from other species of
Pseudocyclammina
and indeed
Buccicrenata
. Wall thickness in
P. rugosa
is
0.17 – 0.50 mm
. 2-3 uncoiled final chambers can occur in both
P. rugosa
and
B.
ex. gr.
subgoodlandensis
. See the Species Key Chart (Appendix) for diagnostic and other characteristics.
Sampò (1969)
illustrated a
Pseudocyclammina
from the Cenomanian of the Iranian Zagros as “
Cyclammina
sp.
(?)”. This relatively small form (external diameter
1.2 mm
) with numerous chambers in the final whorl (in an approximately similar manner to the Late Cretaceous species
Pseudocyclammina sphaeroidea
Gendrot
, see, for example,
Schlagintweit, 1992
) has been occasionally illustrated as
P. rugosa
in other publications on the Cenomanian Sarvak Formation of the Iranian Zagros (e.g., possibly
Esfandyari et al., 2023
). This form has new been described as a new species –
Pseudocyclammina sarvakensis
– by Schlagintweit & Yazdi-Moghadam (2023) (see below).
Stratigraphic Distribution
Albian – latest (?) Cenomanian.
Fig. 30
Cenomanian paleogeographic distribution of
Buccicrenata
ex gr. subgoodlandensis.
Fig. 31
Representative illustrations of
Pseudocyclammina rugosa
: a Equatorial section,
Maync (1952
, pl. 12, fig. 9, France);
b
Equatorial section of uncoiled specimen,
Maync (1959b
, pl. 1, fig. 14, France);
c
Axial section,
Maync (1952
, pl. 12, fig. 8, France).
Neumann et al. (1974)
indicated that at its
type
locality, the species has a middle – late Cenomanian range.
Rey et al. (1977)
and
Saint-Marc (1981)
suggested that across Neotethys, this species ranges throughout the Albian and Cenomanian (see also Crosaz-Galletti, 1979), but in practice, despite many published occurrences, there are very few records of this species that have both plausible illustrations and precise biostratigraphic calibration. Its stratigraphic range may be confused by misidentification of, for example,
Buccicrenata
ex gr.
subgoodlandensis
.
Regarding its distribution within the Cenomanian,
Bilotte (1973
,
1985
) illustrated plausible specimens from the Pyrenees and indicated that the species ranges throughout the Albian and Cenomanian in that region.
Simmons et al. (2020b)
illustrated a probable specimen of
P. rugosa
from the middle Cenomanian of south-east
Turkey
. However, a single axial specimen precludes confident identification.
The Cenomanian record of
Kalantari (1976)
is of
B
. ex. gr.
subgoodlandensis
, likewise the Albian record from the Zagros of
Sampò (1969)
. Illustrated records from the late Cenomanian of
Mexico
(
Aguilera-Franco, 2003
;
Omaña et al., 2013
) are most likely of
Ammobaculites
sp.
(see also unillustrated record by
Aguilera-Franco et al., 2001
). Some illustrated records from the Cenomanian of
Portugal
(
Berthou, 1973
;
Boavida, 2013
;
Andrade, 2018
), appear to be more compatible with
B
. ex. gr.
subgoodlandensi
s or cannot be confirmed as
P. rugosa
. Illustrated records from the Late Cenomanian of
Morocco
(
Ettachfini, 1993
,
2006
;
Ettachfini & Andreu, 2004
) appear to be of
Ammobaculites
/
Lituola
sp.
,
B.
ex. gr.
subgoodlandensis
,
or are indeterminate.
A form named as
Pseudocyclammina
cf.
rugosa
from the Cenomanian of
Tunisia
(
Bismuth et al., 1967
) is small and its identity unclear (see also
Bismuth et al., 1981
for an unillustrated record). Likewise, the records of relatively small “
P. rugosa
”
from the Cenomanian of
Armenia
(
Danelian et al., 2014
).
Illustrated records from the Aptian or older (e.g.,
Kalantari, 1976
;
Afghah & Haghighi, 2014
from the Iranian Zagros) are not this species (that of
Afghah & Haghighi, 2014
=
Ammobaculites
sp.
or
Lituola
sp.
), and unillustrated records from Aptian and older strata (e.g.,
Habibnia et al., 2010
;
Mansouri-Daneshvar et al., 2015
;
Afghah et al., 2016
) should be treated with caution.
An unillustrated report from the Coniacian – Maastrichtian of
Spain
(
Gräfe, 2005
) should most likely be regarded as erroneous.
Cenomanian Paleogeographic Distribution
Western Mediterranean –?Arabian Plate within Neotethys.
As can be understood from the limited number of confirmed records mentioned above, the paleogeographic distribution of this species is hard to determine. It has been described without illustration from the Albian – top Cenomanian of
Lebanon
(
Saint-Marc, 1970
,
1974a
, 1980, 1981); the early Cenomanian of the Dinarides (
Velić, 2007
); the middle and late Cenomanian of
Tunisia
(
Abdallah et al., 1995
;
Touir et al., 2017
); the middle – late Cenomanian of southern
Iraq
(
Al-Dulaimy et al., 2022
); the Sarvak Formation of the Iranian Zagros (
Omidvar et al., 2014a
, b;
Assadi et al., 2016
;
Navidtalab et al., 2020
; Ashgari et al., 2022); Provence (
Babinot et al., 1988
); early Albian – top Cenomanian of
Portugal
(
Rey et al., 1977
;
Berthou & Schroeder, 1978
;
Berthou & Lauverjat, 1979
; Crosaz-Galletti, 1979;
Rey, 1979
); Aquitaine (
Deloffre & Hamaoui, 1979
);
Syria
(
Mouty et al., 2003
); and
Kuwait
(El-Naggar & Al-Rifaiy, 1973). An illustration from the Cenomanian of
Greece
is unclear (Decrouez, 1978). A specimen illustrated as “
Buccicrenata
?
rugosa
” from the early Cenomanian of the
Oman
Mountains (
Simmons & Hart, 1987
) is not clearly this species (it may be
Buccicrenata
ex. grp.
subgoodlandensis
), whilst unillustrated
P. rugosa
has been mentioned from the late Cenomanian of the
Oman
Mountains (
Rabu, 1993
).