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 Orthosphinctes ( Ardescia ) beticus Caracuel, Olóriz & Rodriguez-Tovar, 1999 ( Fig. 13C ) Orthosphinctes ( Ardescia ) betica Caracuel, Olóriz & Rodriguez-Tovar, 1999: 112 , figs 3, 4. MATERIAL EXAMINED. — MI4N top10/1. STRATIGRAPHIC DISTRIBUTION. — Top of bed 10 of section Monte Inici East, Platynota Zone. It has been reported from the middle part of the Platynota Zone ( Caracuel et al . 1999 : fig. 2). DESCRIPTION Evolute, planulate shell. Subelliptical whorl section with slightly rounded flanks that converge towards a rounded venter. The umbilical wall is well developed and the umbilical margin is rounded. The ornamentation is characterized by prorsiradiate ribs, which branch at the outer third of the flank. An intercalatory rib is observed between two bifurcates. At least three constrictions are visible on the last whorl; the deepest one, which is located close to the end of the last whorl, shows a slight adoral convexity. No traces of peristome and sutures are preserved. Measurements: see Table 25. DISCUSSION The poor preservation of this specimen does not allow the detailed study of the ornamental characters. It shows strong morphological similarities in both the ornamentation and the shell structure with the specimen studied by Caracuel et al. (1999 : figs 3, 4), named O. ( Ardescia ) beticus . Species of the subgenus Ardescia described by Atrops (1982) from South- East France show different rib characters.