Content uploaded by Carles Ferràndez-Cañadell
Author content
All content in this area was uploaded by Carles Ferràndez-Cañadell on Feb 06, 2015
Content may be subject to copyright.
Taphos 2014, Ferrara
32
SPHAEROGYPSINA GLOBULUS SENSU LATO (REUSS, 1848) RECENT
AND FOSSIL IN MICRO XCT_400 XRADIA-ZEISS TOMOGRAPHY AND
FILMS
Katica Drobne1, Vlasta
Ćosović2, Johann
Hohenegger3, Antonino
Briguglio3, Janko Čretnik4,
Janez Turk4, Mateja Golež4,
Franc Cimerman1, Tadej
Dolenec5, Laura Cotton6,
Carles Ferràndez-Caňadell7
and Fred Rögl8
1. I. Rakovec Institute of Paleontology ZRC SAZU (Scientific
Research Center SAZU), Ljubljana, Slovenia, katica@zrc-sazu.si
2. Department of Geology, Faculty of Science, University of
Zagreb, Zagreb, Croatia
3. Department of Palaeontology, University of Vienna,
Geozentrum, Austria
4. Slovenian National Building and Civil Engineering Institute,
Ljubljana, Slovenia
5. Department of Geology, Faculty of Natural Sciences and
Engineering, University of
Ljubljana, Slovenia
6. Naturalis Biodiversity Center, Postbus 9517, 2300 RA Leiden,
Netherland
7. Department d'Estratigrafia, Paleontologia i Geociències
Marines, Facultat de Geologia, Universitat de Barcelona, Spain
8. Naturhistorisches Museum Wien, Vienna 1010, Austria
The aim of this study is to provide some basic information to tackle the systematics and the
shell morphology of the globular foraminifer called Sphareogypsina Galloway, 1933. We focus on
the species S. globulus (Reuss, 1848), which, first described as a Bryozoan, seems to be common
in all Palaeogene tropical shallow water carbonates. In fact, it has been recorded in Caribbean,
Mediterranean, and Red Sea to Indo-Pacific sediments from the Palaeocene to the recent.
Although some morphological variations have been reported (e.g., the proloculus size seems to be
larger in the late Eocene than in the Recent) and few genera have been established, all rounded
gypsinids are commonly called S. globulus sensu lato in every bioprovince and from the
Palaeogene onward only due to the lack of detailed morphological characterization of the internal
structures of the juvenile apparatus and its ontogenetic development. The main factor that
hampers a detailed morphological description is the spherical morphology of the specimen which
does not show any equatorial (or axial) plane where the whole embryo can be properly exposed
and studied.
The MicroCT- method offers an accurate interpretation of internal structures, dimensions of
structural elements and volumetric rendering as well as the analysis of ontogenetic development of
foraminiferal tests without test destruction.
To accomplish these tasks, we have scanned almost 30 specimens of well preserved globular
shpaerogypsinids using two main equipments (Micro XCT_400 Xradia – ZEISS from the Slovenian
National Building and Civil Engineering Institute, and the MicroCT- Skyscan1173 from the Institute
of Palaeontology, University of Vienna) and we have observed their embryonic apparatus. So far,
the material we have studied encompasses specimens from the Cuisian (France), Priabonian
(France and Tanzania), Chattian (France), Burdigalian (India), Badenian (Austria) and Recent
(Adriatic Sea, Bay of Aqaba, Florida, Okinawa).
On all specimens we have observed the characteristic “chessboard surface” which seems to be
a variable parameter to be kept into consideration for taxonomic differentiation. Shape and size of
initial chambers and the building mechanisms of the subsequent chambers have been observed on
a three dimensional basis seeming that a number of connections are open between the proloculus
and all the surrounding chambers. The size (in term of volume) between proloculus (P) and
deuteroloculus (D) points, at least in recent specimens, to an isolepidine embryonic apparatus
where both chambers possess similar size (Recent specimen from Florida: P: 4.9·10-5 mm3; D:
4.1·10-5 mm3), while in specimens from the uppermost Eocene it seems to be slightly
nephrolepidine (specimen from Tanzania: P: 9.9·10-5 mm3; D: 2.7·10-5 mm3).
In many other specimens the proloculus is so small (diameter < 20 microns) that is hard to be
recognized and it might point to microspheric generations.
Taphos 2014, Ferrara
33
These first observed differences lead to the conclusion that a profound revision of the genus
Sphaerogypsina is due and necessary (as suggested by Hottinger et al., 1993), and the results
must be compared with data from the literature to check if evolutionary trends are visible and/ or if
palaeo-bioprovinces works as a boundary among taxa or if the genus was and is a cosmopolitan
inhabitant of all shallow water deposits.
Fisica e Scienze della Terra, volume 1 (2014)
Annali Online dell’Università degli Studi di Ferrara
Fisica e Scienze della Terra
Sezione di
7th International Meeting on
Taphonomy and Fossilization
Ferrara, September 10th-13th, 2014
ABSTRACT BOOK
volume 1 (2014)
ISSN 2385-2828
ANNALI ONLINE DELLʼUNIVERSITÀ DI FERRARA
Sezione di
FISICA E SCIENZE DELLA TERRA
Volume 1 (2014)
7th International Meeting on
Taphonomy and Fossilization
10th–13th September 2014, Ferrara, Italy
EDITED BY
DAVIDE BASSI AND RENATO POSENATO
UNIVERSITÀ DEGLI STUDI DI FERRARA
2014
ISSN 2385-2828
DOI dx.doi.org/10.15160/fst.v0i0.919
Annali online dellʼUniversità degli Studi di Ferrara
Autorizzazione del Tribunale di Ferrara n. 36/21.5.53
Bassi D., Posenato R. (eds) 2014. Abstract book of the 7th International Meeting on
Taphonomy and Fossilization, Taphos 2014, Ferrara, September 10th-13th, 2014. Annali
online dellʼUniversità di Ferrara, Sez. Fisica e Scienze della Terra, volume 1.
Copyright © 2014 by
Università degli Studi di Ferrara
Ferrara