Journal of Conchology (2009), Vol.40, No.1 5

A NEW FOSSIL CONOIDEAN FROM THE PLIOCENE OF ITALY,
  WITH COMMENTS ON THE BELA MENKHORSTI COMPLEX
                          (GASTROPODA: CONIDAE)

             Paolo Mariottini1, Carlo Smriglio2 Andrea Di Giulio1 & Marco Oliverio3

                        1Dipartimento di Biologia, Università di Roma Tre, Via Marconi 446, 00146 Roma, Italy
                                                     2Via di Valle Aurelia 134, 00167 Roma, Italy

 3Dipartimento di Biologia Animale e dell’Uomo, Università di Roma “La Sapienza”, V.le dell’Università 32, 00185 Roma,
                                                                               Italy

      Abstract Based on shell characters, the complex of Mediterranean fossil and extant species related to the Recent taxon Bela
      menkhorsti van Aartsen 1988 is critically analyzed. This species is characterised morphologically with respect to both the
      close Recent Bela zenetouae (van Aartsen 1988) and the Plio-Pleistocene form, that are regarded as valid and different taxa,
      only for the different embryonic/larval shell development.
      We formally propose to move Feria zenetoue to the genus Bela Gray 1847 and we describe the fossil form as Bela trinacria
      Mariottini & Smriglio n. sp.
     Key words Bela, taxonomy, larval development, Mediterranean Sea, Recent, Pliocene

                    IntroductIon                       of small Recent and Tertiary turrids with an
The epithet “turrids” has been largely used as         eastern Atlantic distribution, including the
a general term referring to the largest radiation      Mediterranean Sea. As emphasized by Powell
of marine gastropods, traditionally included in        (1966: 98), this genus has been frequently con-
the family-group Turridae H. & A. Adams 1853           sidered as a “basket” for the allocation of a wide
(Tucker, 2004), and currently undergoing sig-          variety of unrelated turrids. As a consequence,
nificant revision (Taylor et al., 1993; Kohn, 1998;    the number of Recent species considered as valid
Bouchet & Rocroi, 2005).                               in the Mediterranean Sea, varies according to dif-
                                                       ferent authors (e.g.: Nordsieck, 1977; Sabelli et al.,
  In the Mediterranean Sea this group of toxo-         1992; Gofas & Le Renard, 2007).
glossate neogastropods includes over 100 species,
classified in 25–30 genera. Supraspecific system-        As with other prosobranch groups, this lineage
atics is still very unstable on a global scale and     includes pairs of sister species which differ only
this is reflected also at the regional level (Powell,  in their larval development, and thus in their
1966; Nordsieck, 1977; Sabelli et al., 1992; Gofas &   protoconch morphology. This was interpreted
Le Renard, 2007).                                      as a good reason to establish a “parallel” genus,
                                                       viz. Fehria van Aartsen 1988, with type species
   The α-taxonomy of the Recent Mediterranean          Ginnania taprurensis Pallary 1904 (Figs 28a–c),
species, largely based on shell characters, also       characterised (and distinguished from Bela) by
suffers from a lack of comprehensive and mod-          a non-planktotrophic larval development, and a
ern revisions. Species-rich groups like Raphitoma      paucispiral protoconch. We agree with Bouchet
or Mangelia are currently under revision by col-       (1990) that most of the turrid genera erected on
leagues and significant changes to the tradi-          this basis are clearly polyphyletic and should
tional arrangements are expected (pers. comm.:         not be used. The cases of Bela menkhorsti van
F. Pusateri & R. Giannuzzi-Savelli and G. Spada,       Aartsen 1988 and Fehria zenetoue van Aartsen
respectively).                                         1988 provide striking examples. The two taxa
                                                       have nearly indistinguishable teleoconchs,
  The genus Bela Gray 1847 was based on Murex          and can be diagnosed only by their different
nebula Montagu 1803, whose identity is uncer-          protoconchs.
tain and would deserve a careful analysis. The
genus has been redescribed by Powell (1966:              The commonly accepted interpretation is that
97) and according to such definition consists          B. menkhorsti was originally described as
                                                       Pleurotoma nana by Scacchi (1836: 13). This
Contact author : mariotpa@unirma3.it                   binomen was however preoccupied by P. nana