Biodiversity Journal, 2014, 5 (2): 141–146 M ONOGRAPH On the systematic position of “Cima” melitensis Mifsud, 1998, with erection of the new genus Mifsudia (Heterobranchia Cimidae) Paolo Mietto1, Italo Nofroni2* & Ermanno Quaggiotto3 1 Università degli studi di Padova, Dipartimento di Geoscienze, via Gradenigo 6, 35131 Padova, Italy; e-mail: paolo.mietto@unipd.it Via B. Croce 97, 00152 Roma, Italy; e-mail: italo.nofroni@uniroma1.it 3 Via Secula 13, 36023 Longare, Vicenza, Italy; e-mail: ermanno@quaggiotto.net * Corresponding author 2 ABSTRACT Based on teleoconch and, especially, protoconch features, the new genus Mifsudia is erected for Cima melitensis Mifsud, 1998 and placed in the family Cimidae. The protoconch is hyperstrophic, as in the other cimids. At least, two European fossil species (Cima gantensis Bandel, 2005, from the Middle Eocene of Hungary and Murchisonella cf. obtusa Gougerot & Le Renard, 1978 from Early Oligocene of France) are also included in the new genus. Mifsudia melitensis (Mifsud, 1998) comb. nov., originally described from Malta, is here recorded for the first time from Lampedusa Island, Alboran Sea and the coasts of Mauritania (West Africa). KEY WORDS Gastropoda; Cima; Murchisonella; Mifsudia; Mediterranean Sea; Western Africa. Received 28.01.2014; accepted 21.03.2014; printed 30.06.2014 Proceedings of the Seventh Malacological Pontine Meeting, September 9th-10th, 2013 - San Felice Circeo, Italy INTRODUCTION During the in progress revision of the genus Cima Chaster, 1896 (Heterobranchia Cimidae) in the Mediterranean Sea, we examined several specimens of Mediterranean and Atlantic “Cima” and recorded notable differences on the protoconchs. This drove us to investigate in depth this complex group of Heterostropha and allowed recognizing two different typologies of protoconchs: the first one is globular, tipical of Cima sensu strictu (e.g. Cima minima Jeffreys, 1858, Fig. 5), the second one is clearly hyperstrophic (e.g. Cima melitensis Mifsud, 1998, Figs. 1– 4). This latter type, resembles the protoconch of some Murchisonella Mørk, 1875 (Warén, 2013) but is clearly distinguishable. This double typology of protoconch can be recognized in the fossil species referred to “Cima” (Warén, 2013). The known species attributable to the genus Cima, for the Mediterranean and European sea waters (C. minima; C. cylindrica Jeffreys, 1856; C. cuticulata Warén, 1993; C. inconspicua Warén, 1993; C. apicisbelli Rolan, 2003) consist of a morphologically homogeneous group. One exception is “Cima” melitensis, described by Mifsud (1998) from a limited number of specimens coming from 80–100 m deep Malta’s waters, and lacking of soft tissue. This species is characterized by a pyramidelliform teloconch, surmounted by a protoconch that seems truncated; at a first sight the shell resembles closely Odostomia Fleming, 1813 or Liostomia G.O. Sars, 1878. 142 P. MIETTO, I. NOFRONI & E. QUAGGIOTTO The analysis at SEM of some shells highlighted a very peculiar protoconch, certainly different from Pyramidellidae: after an extremely small nucleus (about 27 µm), the protoconch unwinds on an horizontal axis for half a rotation; then it raises, creating a small prominence easy visible in lateral view (Fig. 4); then it goes down and continues with a normal dextrorse envelopment. This kind of protoconch is called hyperstrophic and is typical of some families of Heterobranchia (Heterostropha) such as Architectonicidae, Murchisonellidae, etc. Basing on these morphological features we believe that the collocation of this species into the genus Cima is incorrect. Chaster (1896) instituted the subgenus Cima (ex Monterosato) without any description, just declaring that “... which Jeffreys described as Odostomia minima, for which species and the closely allied but quite distinct Jeffreysia cylindrica Jeffr., Monterosato proposes the sub-genus Cima, a separation with which I entirely concur.” One first problem is to determine which is the type species of Cima. Following Warén (1993) this is Odostomia minima Jeffreys, 1858, while Bandel (2005) indicates as type species Jeffreysia cylindrica Jeffreys, 1856. The work of Warén (1993) is earlier and then the correct type species for Cima is Odostomia minima. Van Aartsen (1981) validates the separation between Cima and Pherusina Norman, 1888 (=Aclis Lovén, 1846), proposed by Monterosato, but, basing on morphological features such as the shape of peristome, the embrional whorls, the clear flexuous growth lines, he considers valid the position of the genus in Aclididae. The same opinion is shared by Fretter & Graham (1982), that nevertheless do not exclude to put this genus in a new, to be created, family Cimidae. Afterwards Graham (1988) preserves the collocation of Cima in Aclididae. Warén (1993), mainly on anatomical base, puts Cima in the new monogeneric family Cimidae, into the subclass Heterobranchia. Bouchet & Rocroi (2005) maintain Cima in the Cimidae family, into the Heterobranchia, but without further collocation. Bandel (2005) discusses the collocation of many genera, now included in Heterostropha, such as Aclis Lovén, 1846, Hemiaclis G.O. Sars, 1878, Graphis Jeffreys, 1867, Cima, Murchisonella Mörch, 1875, and Ebala Gray, 1847. The result, based on anatomy, shell morphol- ogy and evolutionary trend, is that all these genera have to be included in different families. In particular, Cima is re-positioned in Streptacididae, a family that includes other fossil genera from the Paleozoic. Murchisonella is included in the Donaldinidae family, including fossil genera from Carboniferous. The Ebalidae (= Anisocyclidae) is considered separated family. Recently, Peñas & Rolán (2013) reviewed the genus Murchisonella and proposed using the genus Pseudoaclisina Yoo, 1994 for the species with rounded coils; in the same year Warén (2013) published a study about Murchisonellidae, where he analyzed this family and other similar ones, basing on genetic, anatomical and palaeontological features, providing guidelines on these small Heterobranchia for future studies. The morphological differences that all the Authors recognize between Cima and Murchisonella regard the shape of the protoconch and the presence of growth lines: Cima does not have the deep sinus close to the suture that characterizes Murchisonella. Moreover, Murchisonella has a scalariform profile, while in Cima it is rounded. Considering the Cima species, both the type species Odostomia minima Jeffreys, 1858 and then Jeffreysia cylindrica Jeffreys, 1856 present a globular and slightly inclined protoconch (Figs. 5, 7, 8), completely different from those of melitensis. The features of the protoconch of C. melitensis bring the species close to the genus Murchisonella, whose type species Murchisonia (Murchisonella) spectrum Mørk, 1875 (Fig. 9), comes from the Caribbean area (Redfern, 2001). This genus is characterized by an aclidiform shell, densely striated in the middle and inferior part of the whorls, with a sinus in the upper part of the external peristome edge, and hyperstrophic protoconch. The only species attributed to this genus, reported in the Mediterranean, is Murchisonella mediterranea Peñas & Rolán, 2013 (= Murchisonella columna Auctores not Hadely, 1807). With both these species C. melitensis shares only the protoconch and not the growth style or the shape of the whorls that are in common with Cima. Thus, we think that C. melitensis has to be attributed to a distinct genus, but none of the known ones, both from fossil and living records, seems suitable. So we believe it is necessary to institute a new genus. On the systematic position of “Cima” melitensis, with erection of the new genus Mifsudia (Heterobranchia Cimidae) 143 Figure 1. Mifsudia melitensis, Mauritania, -80/100 m (1.1 mm). Figure 2. Mifsudia melitensis, Mauritania, -80/100 m (0.98 mm). Figure 3. Mifsudia melitensis, Mauritania, -80/100 m, protoconch of shell in Fig 2. Figure 4. Mifsudia melitensis, protoconch, lateral view, Mauritania, -80/100 m. Figure 5. Cima minima, protoconch, Giannutri Island, Grosseto, Italy, -18 m. Figure 6. Cima sp., Getares, Algeciras, Spain, beach (0.86 mm). Figure 7. Cima cf. cylindrica, Sorrento, Naples, Italy, -50/60 m (1.48 mm). Figure 8. Cima cylindrica, Levanzo Island, Trapani, Italy, -31 m (1.45 mm). Figure 9. Murchisonella spectrum, Varadero, Bahía de Cochinos (Cuba), -10 m (1.4 mm). 144 P. MIETTO, I. NOFRONI & E. QUAGGIOTTO ACRONYMS. Franco Gubbioli collection, Marbella, Málaga, Spain = FG. Paolo Mietto collection, Vicenza, Italy = PM. Italo Nofroni collection, Rome, Italy = IN. Ermanno Quaggiotto collection, Longare, Vicenza, Italy = EQ. RESULTS SYSTEMATIC Class GASTROPODA Cuvier, 1797 Subclass HETEROBRANCHIA Gray, 1840 (unassigned) Infraclass HETROBRANCHIA Gray, 1840 Family CIMIDAE Warén, 1993 Genus Mifsudia n. gen. TYPE SPECIES. Cima melitensis Mifsud, 1998: Figs. 4, 5. ExAMINED MATERIAL. “Cima” melitensis. Lampedusa Island, Cala Calandra, -30 m, legit M. Oliverio, 1 shell (IN). Between Estepona (Malaga, Spain) e Tetuan (Morocco), -25/35 m, 1 shell (IN). Mauritania (West Africa, Atlantic Ocean), - 80/100 m, more than 40 shells, legit F. Gubbioli, (FG, PM, IN, EQ). All inedited reports. Malta, Golden Bay, -100/120 m, legit F. Carmona, 1 shell (EQ). Cima minima: more than 60 shells from all the Mediterranean Sea, from 0 to 180 m of depth (PM, IN, EQ). Cima cylindrica. More than 60 shells from all the Mediterranean Sea, from 0 to 100 m of depth (PM, IN, EQ). Cima sp. 2 shells from Getares (Algeciras. Spain), beach, inedited report (IN). Rumi (Sudan, Red Sea), - 60 m, legit M. Oliverio, 1 shell (IN). DESCRIPTION. Small shell, white, bright, lacking in the spiral sculpture, widely umbilicate, with the shape similar to Odostomia; rounded whorl with growth lines flexuous but lacking in the subsutural sinus. External peristome edge thin and sharp, lacking in sinus. Hyperstrophic protoconch with probable planctotrophic development. ETIMOLOGY. The name has been coined in honor of Constantine Mifsud, the well known Maltese malacologist, discoverer of C. melitensis. REMARkS. Composition of the genus: Mifsudia melitensis Mifsud, 1998 - living, Mediterranean Sea and Atlantic Ocean Mifsudia gantensis Bandel, 2005 - fossil, Middle Eocene, Hungary (= Cima gantensis) Mifsudia sp. (= Murchisonella n. sp.? pro Murchisonella cf. obtusa Gougerot & Le Renard, 1978) fossil, Early Oligocene, France, see below. DISCUSSION As previously discussed, the new genus Mifsudia n. gen. differs from Cima for the shape of the protoconch, hyperstrophic and not globular; the shape of the growth lines, sinuous (sigmoids) but always lacking in the subsutural sinus. The rounded shape of the whorls is similar in both genera. Mifsudia n. gen. and Murchisonella share the same typology of hyperstrophic protoconch but not the shape of the whorls, that in the latter is clearly angular, nor the shape of the growing lines that in Murchisonella is sigmoid and characterized by a deep sinus in the subsutural area. These differences occur also in the fossil forms, at least from Lutetian (Middle Eocene). Thus, to be included in Mifsudia there are: Murchisonella mediterranea. Aydincik (Turkey), -27 m, , legit M. Oliverio, 1 shell (IN). 1) Cima gantensis Bandel, 2005 from the Middle Eocene of Hungary. 2) Murchisonella n. sp.? pro Murchisonella cf. obtusa (in Gougerot & Le Renard, http.//www.somali.asso.fr/fossils/biotaxis.php, fische batch LR71951) from the Early Oligocene (Stampiano Auct.) of France. Murchisonella sp. Watamu (kenia, Indian Ocean), -32 m, legit L. Contessini, 1 shell (IN). Shaiab According to Le Renard (http://www.somali.asso.fr/ fossils/biotaxis.php), Janssen A.W. (1984), because of Murchisonella spectrum. Varadero (Cuba, Caraib Sea), beach, legit C. Petrella, 1 shell (EQ). Bahía de Cochinos (Cuba, Carribean), debris -10 m, legit M. Chiodi, 7 shells (IN). On the systematic position of “Cima” melitensis, with erection of the new genus Mifsudia (Heterobranchia Cimidae) 145 the features of the protoconch and of the growth lines, have to be referred to Cima the fossil species Cima gougeroti Le Renard, in schedis, from the Lutetian of the Paris Basin (http.//www. somali.asso.fr/fossils/biotaxis.php, batch 60859 and 61595), Cima microscopica Le Renard, in schedis, from the Lutetian and “Biarritzian” of the Paris Basin (http.//www.somali.asso.fr/fossils/biotaxis. php, batch 73241), Aclis (Stilbe) proneglecta R. Janssen, 1978 from the Upper Oligocene of Glimmerode (Germany), Aclis (Stilbe) neglecta A.W. Janssen, 1969 from the Miocene of Dingden (Germany). According to Pachaud & Le Renard (1995) should be referred to Murchisonella the fossil species Aciculina emarginata Deshayes, 1861, Murchisonella densesulcata Gougerot, 1966 and M. obtusa Gougerot & Le Renard, 1978, all from the Lutetian of the Paris Basin. The presence of clear distinctive characteristics among these three genera, highlighted since the Lutetian, supports the validity of the new genus Mifsudia. About what concerns the systematic collocation of the new genus, we have to confess some embarrassment because the previous Authors used several and different criteria for the collocation of the genera at the family level. We think that what proposed by Bandel (2005) is not completely shareable because we separate Mifsudia from Cima due to the protoconch shape, without considering other anatomical characteristics. Without starting a systematic discussion, it has to be considered that Bandel (2005) and Warén (2013) used as criterion the teloconch feature rather than the protoconch. Following this rule, the absence of the characteristic sinus in the growing lines, typical of Murchisonella and Pseudoaclisina, gives credit for the collocation of Mifsudia in Cimidae. 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