Passendorferia (Enayites) aff. gygii Brochwicz-Lewinski & Rozak, 1976

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 : 523

Passendorferia (Enayites) aff. gygii Brochwicz-Lewinski & Rozak, 1976 ( Fig. 7E)

MATERIAL EXAMINED. — MI4N 8 “top”/6.

STRATIGRAPHIC DISTRIBUTION. — The specimen has been collected in bed 8d of section Monte Inici East, assigned with doubt to the Hauffianum Subzone of the Late Oxfordian Bimammatum Zone. P. (E.) gygii has been reported from older levels of the Bimam matum Zone, namely the Hypselum Subzone or the lower part of the Bimammatum Subzone ( Meléndez 1989).

DESCRIPTION

Evolute shell with subcircular whorls. The flanks are flat or gently rounded, the ventral area is large and rounded. No umbilical wall is developed. Dense, radial to gently prorsiradiate ribbing which is characterized by simple and biplicate ribs. The latter bifurcate at the ventrolateral margin. Two constrictions per whorl have been observed. No parabolic nodes have been observed. Due to the lack of any traces of suture line the diameter of the beginning of the body chamber cannot be observed. Measurements: see Table 9.

DISCUSSION

The studied specimen shows some morphological affinities with P. (E.) gygii . However, the whorl shape, the fine, dense ribbing, the presence of parabolic nodes and also the prorsiradiate direction of the secondary ribs suggest keeping it distinct from P. (E.) gygii sensu stricto.