Physodoceras cf. wolfi (Neumayr, 1873)

Cecca, Fabrizio & Savary, Bérengère, 2007, Palaeontological study of Middle Oxfordian- Early Kimmeridgian (Late Jurassic) ammonites from the Rosso Ammonitico of Monte Inici (north-western Sicily, Italy), Geodiversitas 29 (4), pp. 507-548 : 537

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 .

Figures

FIG. 12. — A, Physodoceras cf. wolfi (Neumayr, 1873), specimen MI4N 8c/3 from bed 8c of section Monte Inici East; B, Benetticeras cf. benettii Checa, 1985, specimen MI4W 8c top/1 from bed 8d of section Monte Inici East; C, Euaspidoceras cf. radisense (d’Orbigny, 1850), specimen MI4N 8 “top”/8, from bed 8top of section Monte Inici East. All figures natural size. Arrows indicate the beginning of the body chamber.