“ 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
Pseudorhapydionina chiapanensis
Michaud et al., 1984
Reference Illustration & Description
Michaud et al. (1984)
, Pls. 1 & 2 (not 11-14), p. 35-37.
Pseudorhapydionina chiapanensis
is similar in respects to both
P. dubia
and
P. laurinensis
.
Michaud et al. (1984)
outlines the main differences as
P. chiapanensis
having a thicker wall and less depressed sutures compared with
P. laurinensis
and a more parallel-sided seriate portion compared with
P. laurinensis
which is more flaring. It has somewhat more chambers in the seriate portion than
P. dubia
.
Consorti et al. (2016b)
notes it has fewer internal septula in the seriate portion than
P. dubia
and
P. laurinensis
, and which are thick, medium length and thickened at the base. See the Species Key Chart (Appendix) for diagnostic and other characteristics.
Stratigraphic Distribution
Early – late (but not latest) Cenomanian.
Originally described from the early – middle Cenomanian of southern
Mexico by
Michaud et al. (1984)
who associated the new species with
Rotalipora apenninica
(Renz)
(=
Thalmanninella appenninica
) (late Albian – lower late Cenomanian; Bidgood &
Simmons, 2022
). However,
T. apenninica
is not illustrated, so there is something of a question mark over the oldest age of
P. chiapanensis
.
Aguilera-Franco (2000
,
2003
) associated
P. chiapanensis
with
P. dubia
which she stated was a middle – late Cenomanian species.
Aguilera-Franco & Allison (2004)
placed the extinction of
P. dubia
within the late Cenomanian.
Cenomanian Paleogeographic Distribution
Central America/Caribbean.
This species was originally described and illustrated from the
Chiapas region
in the far south of
Mexico
(
Michaud et al. 1984
) and has subsequently only been reported from that region (i.e., the Maya Block), including
Guatemala
. Records include from the Guerrero-Morelos Platform (
Aguilera-Franco et al., 2001
;
Aguilera-Franco, 2000
,
2003
(illustrated); Aguilera-Franco & Romano, 2004;
Aguilera-Franco & Allison, 2004
;
Bomou et al., 2019
). Other records from southern
Mexico
include
Michaud & Fourcade (1989)
,
Rosales-Dominguez et al. (1997
,
1998
illustrated);
Cros et al. (1998)
and
Martens & Sierra-Rojas (2021)
. Records from
Guatemala
include
Michaud et al. (1992)
;
Fourcade et al. (1999)
;
Moeschler (2009
, illustrated);
Caceres Flores (2016
, illustrated) and
Radmacher et al. (2021
, illustrated). It was not reported by
Omaña et al. (2012
,
2019
) from central
Mexico
which suggests a very restricted area of distribution.