Ranina sp.

Palace, Bourbonic Royal, Maio, Nicola, Mancini, Donato, Mezzasalma, Marcello, Odierna, Gaetano, Petraccioli, Agnese, Nugnes, Francesco, Picariello, Orfeo Lucio Antonio & Guarino, Fabio Maria, 2015, Short communications Extinct or not extinct: the case of the Chalcides ocellatus (Squamata: Scincidae) population from the Park of the ex Bourbonic Royal Palace of Portici (Naples, Italy), Natural History Sciences 2 (1), pp. 43-54 : 50-52

Ranina sp.

Figs. 1A , 2

Material: one incomplete carapace crushed and partially displaced (MSNM i28047: about 60 mm long).

Description: Incomplete carapace preserving only part of the shield and the two left anterolateral spines; carapace convex, with isolated forward-directed spiny tubercles, sparse dorsally alternating with smaller ones (notably on the anterolateral margin); margin of carapace and both anterolateral spines with a rim of small pointed spines; first anterolateral spine broken and slightly displaced but bifid, whereas the second one is trifid.

Discussion. Even though incomplete, the studied specimen shows the diagnostic dorsal ornamentation of the carapace of the fossil and extant representatives of Ranina , having more or less spiny and uniformly arranged spines or tubercles. Based upon these characters, the studied specimen is confidently ascribed to Ranina sp. The dorsal characters of the studied specimen were compared with the ornamentation of two species assigned to the genus and reported to date, according to Karasawa et al. (2014): P. propinqua Ristori, 1891 , from the Pleistocene of the Mediterranean basin ( Fig. 1B,C ) and the fossil and extant R. ranina (Linnaeus, 1758) from the Pleistocene of Japan and actually widespread in the Indo-Pacific area ( Fig. 1D ). The comparison has indicated some morphological affinities between the studied specimen and R. propinqua , especially in having the first anterolateral spine bifid (Pasini, Garassino & De Angeli in Baldanza et al., 2014: 214; De Angeli, Garassino & Pasini in Famiani et al., 2015). Moreover, the studied specimen differs notably in ornamentation and arrangement of the carapace spines from the other incomplete sole Pliocene specimen recently reported from Piedmont by Pasini & Garassino (2015).

Unfortunately, the poor preservation of the specimen, lacking most of the carapace, the frontal region, and rostrum, does not allow a specific attribution. Regardless, this new report is very important because it is the second record of the presence of Ranina from the Pliocene of the Mediterranean basin, bridging the presumed age gap between the fossil species and the extant and fossil R. ranina . Finally, a habitat of warm shallow waters environment is here confirmed for this genus, as previously suggested also for R. propinqua from the early to late Pleistocene of Italy (Baldanza et al., 2014; Garassino et al., 2014; Famiani et al., 2015).

Figures

Fig. 1 - Adult specimen of Chalcides ocellatus recently found at Portici (Naples).

Fig. 2 - Study site.