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6 E. Borghi and V. Garilli

Downloaded by [vittorio garilli] at 22:43 08 June 2016  et al. 2012). A remarkable subsidence phase occurred at      Figure 3. Scatter diagrams of some morphological parameters
                                                        about 2.3À2.1 Ma, triggering a generalized, marked deep-     of Placentinechinus davolii gen. et sp. nov.; diameters of A, the
                                                        ening of the basin in the middleÀlate Gelasian (Capraro      apical system (Da) and B, the peristome (Dp) plotted against the
                                                        et al. 2006). This phase correlates with the precession-     test diameter (D), n D 132.
                                                        controlled sapropels B1-B7 of Lourens et al. 1996 (Cap-
                                                        raro et al. 2006). The deepening trend seems to have         Punta Marsala respectively, in the south-eastern part of
                                                        occurred up to the late Calabrian, throughout the large      Favignana Island (Aegadian Archipelago, off western
                                                        Gephyrocapsa zone (Scarponi et al. 2014).                    Sicily). Four specimens from sites P1À2 and C1 were col-
                                                                                                                     lected by Luca Bertolaso (Correggio, Italy).
                                                           The southernmost investigated sites are from the Favig-
                                                        nana Island, Aegadian Archipelago, a few kilometres off         The material is housed at the Museo Geologico G. Cor-
                                                        the western coast of Sicily (Fig. 2A, F). The archipelago    tesi of Castell’Arquato, near Piacenza (northern Italy),
                                                        is an emergent part of the Egadi thrust belt (Abate et al.   with the inventory code MG. Most specimens are pre-
                                                        1995, 1997), within the Sicilian Maghrebian system (Sulli    served as complete coronas and were picked up by hand.
                                                        2000; Nigro & Renda 2001). This area represents the          Some of these tests still preserve spines. Sieved bulk
                                                        westernmost sector of the Sicilian orogenic belt, which is   samples provided test fragments, loose spines and lantern
                                                        mainly comprised of Neogene south-verging fold-thrust        ossicles, but no apical plates were found. Detailed morpho-
                                                        tectonic elements (Tondi et al. 2012 and references          logical analyses were carried out using a Zeiss DSM 940
                                                        therein). Favignana Island is formed by Triassic to Eocene   and a Jeol JSM 5610 LV scanning electron microscope at
                                                        deposits, cropping out in its western part, unconformably    the Salamanca University (Spain) and at the Museo Civico
                                                        covered by late Cenozoic sediments that mainly consist of    di Storia Naturale of Milano (Italy), respectively.
                                                        Early Pleistocene calcarenites and calcirudites. Our sites
                                                        belong to these Pleistocene calcarenite deposits, which         A bivariate statistical biometric analysis (Fig. 3) on the
                                                        have been compared to the Apulian Calcarenite di Grav-       new species described was carried out based on 133 whole
                                                        ina Formation (Sla˛czka et al. 2011 and references          tests, 122 of them collected from the layer immediately below
                                                        therein); they crop out mainly in the eastern slope of the   the calcarenite bed at site E1 (see hereafter and Fig. 4), 10
                                                        emerged palaeo-Favignana, in a pull-apart basin. Gener-      from sites F1À2, one from site P1. The species has been
                                                        ally, these deposits have been interpreted as having been    defined by four raw test measurements, D, H, Dp and Da, and
                                                        formed in a moderate to high energy coast with beach to      three shape ratios, Da/D, Dp/D and H/D (Table 1).
                                                        offshore successions and a mobile bar system (Sla˛czka
                                                        et al. 2011; Slootman et al. 2012). Several litho- and icn-     Classification follows Kroh & Smith (2010).
                                                        hofacies have been recognized within the calcarenites in
                                                        Favignana (Tondi et al. 2012; Uchman et al. 2012).           Study sites

                                                        Material and methods                                         Sites from north Italy. Most specimens were collected
                                                                                                                     from the E1 site (4451019.1600 N 952027.1000 E), in the
                                                        Measurement abbreviations
                                                        D, test diameter measured at the ambitus; Da, diameter of
                                                        the apical system; Dp, diameter of the peristome; H, test
                                                        height; nA and nIa, maximum number of plates in ambu-
                                                        lacral and interambulacral columns, respectively.

                                                        Material and biometric analysis
                                                        The studied material consists of 189 specimens, collected
                                                        (mostly by the first author) from the following late Ceno-
                                                        zoic Italian sites (Fig. 2): E1 (Castell’Arquato, Arda
                                                        River, Piacenza), E2 (San Nicomede, Stirone River,
                                                        Parma), E3 (Rio Gisolo, Fidenza, Parma) and E4 (San
                                                        Polo d’Enza, Reggio Emilia), all in Emilia Romagna,
                                                        north Italy; P1 (Cala Corvino, Monopoli, Bari) and P2
                                                        (Torre Sant’Andrea, Otranto, Lecce), both in Puglia, south
                                                        Italy; C1 (at about 0.5 km NNE from Sant’Anna village
                                                        and a few metres from European route E90) near Crotone,
                                                        Calabria, south Italy; F1 and F2, at Grotta Perciata and
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