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Biodiversity Journal 2014, Monograph: 225-358

  • Biodiversity Journal, 5 (2): 225-228 - MONOGRAPH
    Paolo Stara
    Preface. Studies on extant and fossils astriclypeids (Echinoidea Clypeasteroida)
  • Biodiversity Journal, 5 (2): 229-232 - MONOGRAPH

    Paolo Stara & Daniele Fois
    Dispute about Echinodiscus Leske, 1778 and Amphiope L. Agassiz, 1840 (Echinoidea Astriclypeidae)

    ABSTRACT
    Between the late 1800s and early 1900s, some European echinologists gave rise to a dispute over belonging to the genus Amphiope Agassiz, 1840, rather than Echinodiscus Leske 1778, of some lunulate scutelliforms present in the Oligocene-Miocene deposits of France and Italy. The problem has never been resolved, due to the fact that these echinologists considered the similarities or differences in shape, rather than structural ones. One of the nodes of the dispute was the variability in shape and size of the lunules in Amphiope. Because of all these problems, and also because of the impossibility to obtain and examine the structures of some type specimens of several species established in the past, the recognition of new species is very complicated and research carried out so far, in many cases is doubtful or controversial.

  • Biodiversity Journal, 5 (2): 233-244 - MONOGRAPH

    Paolo Stara & Roberto Rizzo
    Paleogeography and diffusion of astriclypeids (Echinoidea Clypeasteroida) from Proto-Mediterranean basins

    ABSTRACT
    In this paper, the authors retrace the geological changes that during the Neogene have modified the paleogeography of the Western Mediterranean up to its current set-up. It is assumed that migration and probably also speciation of the involved astriclypeids (particularly Amphiope L. Agassiz, 1840 and Echinodiscus Leske, 1778) are closely related to those changes.

  • Biodiversity Journal, 5 (2): 245-268 - MONOGRAPH

    Paolo Stara & Enrico Borghi
    The echinoid genus Amphiope L. Agassiz, 1840 (Echinoidea Astriclypeidae) in the Oligo-Miocene of Sardinia (Italy)

    ABSTRACT
    The records of the genus Amphiope Agassiz, 1840 (Astriclypeidae) from Sardinia are revised on the basis of 110 specimens, collected from 15 localities of Oligo-Miocene age. Since the morphological characters stated in the literature to distinguish the species of Amphiope described in this region cannot provide a clear separation between them, analyses of the plate patterns and of the internal test structure are introduced as taxonomic tools useful for species-level taxonomy in this genus. Five different species of Amphiope are identified. Three of the six species erected on the basis of fossil material from Sardinia are confirmed as valid: Amphiope lovisatoi Cotteau, 1895, A. montezemoloi Lovisato, 1911 and A. nuragica (Comaschi Caria, 1955). Two additional species are left in open nomenclature. The morphological descriptions and the stratigraphical distributions are updated and improved.

  • Biodiversity Journal, 5 (2): 269-290 - MONOGRAPH

    Paolo Stara & Maurizio Fois
    Analysis on a sample of Echinodiscus cf. auritus Leske, 1778 (Echinoidea Clypeasteroida)

    ABSTRACT
    In order to ascertain the extent of the natural intraspecific variability of living and fossil echinoids belonging to the family Astriclypeidae Stefanini, 1912, morphometric and structural aspects were examined in a number of specimens of extant Echinodiscus cf. auritus Leske, 1778, from Madagascar and Philippines. The data obtained will be compared, in a following work, with those of other echinoids belonging to the same family. The analysis of the results indicates, for the sample studied, a great variability in the length of the posterior ambulacral notches, in the petaloid length and in the position of the periproct respect to the posterior margin, while the study of the complete scheme of the plates has clarified the sta- bility and constancy of some parts of this scheme and the variability of other. On the basis of these observations, it has been claimed that the variability of these measures is not so extensive as to affect or determine specific distinctions, if used without careful analysis of the plating pattern in particular in the interambulacrum 5 and in the ambulacra I and II. The results of these analyses, finally, suggests that these echinoids belong to a different genus, than Echinodiscus Leske, 1778.

  • Biodiversity Journal, 5 (2): 291-358 - MONOGRAPH

    Paolo Stara & Luigi Sanciu
    Analysis of some astriclypeids echinoids (Echinoidea Clypeasteroidea)

    ABSTRACT
    The systematic position of some astriclypeid species assigned through times to the genera Amphiope L. Agassiz, 1840 and Echinodiscus Leske, 1778 is reviewed based on the plating pattern characteristics of these two genera universally accepted, and on the results of new studies. A partial re-arrangement of the family Astriclypeidae Stefanini, 1912 is herein proposed, with the institution of Sculpsitechinus n. g. and Paraamphiope n. g., both of them characterized by a peculiar plating-structure of the interambulacrum 5 and of the ambulacra I and V. Some species previously attributed to Amphiope and Echinodiscus are transferred into these two new genera. Two new species of Astriclypeidae are established: Echinodiscus andamanensis n. sp. and Paraamphiope raimondii n. sp. Neotypes are proposed for Echinodiscus tenuissimus L. Agassiz, 1840 and E. auritus Leske, 1778, since these species were still poorly defined, due to the loss of the holotypes and, for E. auritus, also to the unclear geographical/stratigraphical information about the type-locality. A number of additional nominal fossil and extant species of "Echinodiscus" needs revision based on the same method.