Palaeontological study of Middle Oxfordian- Early Kimmeridgian (Late Jurassic) ammonites from the Rosso Ammonitico of Monte Inici (north-western Sicily, Italy)
Author
Cecca, Fabrizio
Université Pierre et Marie Curie-Paris 6, CNRS-UMR 5143 “ Paléobiodiversité et Paléoenvironnements ”, case 104, 4 place Jussieu, F- 75252 Paris cedex 05 (France) cecca @ ccr. jussieu. fr
Author
Savary, Bérengère
Schlumberger Stavanger Research, Risabergveien 3, Tananger, P. O. Box 8013, N- 4068 Stavanger (Norway) BSavary @ stavanger. oilfield. slb. com
text
Geodiversitas
2007
29
4
507
548
journal article
10.5281/zenodo.4651042
1638-9395
4651042
Physodoceras
cf.
wolfi
(Neumayr, 1873)
(
Fig. 12A
)
MATERIAL EXAMINED. — MI4N 8c/3.
STRATIGRAPHIC DISTRIBUTION. — The specimen has been collected in bed 8c of section Monte Inici East, assigned with doubt to the Hauffianum Subzone of the Late Oxfordian Bimammatum Zone.
DESCRIPTION
Moderately evolute shell, with a deep umbilicus and a large whorl section. Whorl flanks are almost flat and converge towards a rounded, large venter. The umbilical wall is steep and the umbilical margin is rounded. Due to crushing, the whorl section is not correctly observable in the body chamber. The ornamentation is made of small, rounded, periumbilical tubercles. The suture line is characterized by L as deep as E and S
1
slightly higher than S
2
. Measurements: see
Table 21.
DISCUSSION
The preservation does not allow a firm identification of this specimen. A similar species is
P. insulanum
(Gemmellaro, 1874)
, which has been considered synonym of
P. wolfi
by
Checa (1985)
. In the recent revision of the Gemmellaro species,
D’Arpa & Meléndez (2002)
keep the latter distinct from
P. wolfi
because of the wider whorl-breadth and the stronger tubercles. The characters visible in the phragmocone of our specimen suggest the comparison with
P. wolfi
.