caa a22 4500 469057076 CHVBK 20180323132847.0 cr unu---uuuuu 170328e19920601xx s 000 0 ita 10.1007/BF03002970 doi (NATIONALLICENCE)springer-10.1007/BF03002970 Azzaroli A. Centro Interdipartimentale Museo di Storia Naturale e del Territorio Université degli Studi di Pisa Via Roma, 103 -56011, Calci, PI aut Considerazioni sulle echinofaune neogeniche italiane [Elektronische Daten] [A. Azzaroli] Observations on the Italian Neogene Echinoid associations In the present work we are going to examine the Echinoid associations coming from the miocenic and pliocenic Italian sediments. The miocenic association is well diversified in its various sistematic levels and it consists of 9 orders, 23 families, 49 genera and more than 300 already identified species. The association presents high modernity degree with regard to the sistematic levels of order and family while the extinct taxa are more numerous within the generic and specific levels. The pliocenic association shows a smaller taxpnomic diversity compared with the previous one; it consists in fact of 7 orders, 13 families, 19 genera and about 70 species. The disappearance, or the drastic reduction, of the miocenic taxa of tropical affinities, actually widespread in the warm seas, is probably due to a change in the palaeoenvironmental conditions. The pliocenic fauna represents a notable impoverishment of the miocenic one and its composition is very similar to that of the living Mediterranean community. The persistence of the miocenic elements in the pliocenic fauna can be attributed to their survival in the areas bordering the basin (Portugal and Atlantic coast of Africa to the equatorial zone) and their successive reintroduction during the lower Pliocene. Accademia nazionale dei Lincei, 1992 Echinoids nationallicence Miocene nationallicence Pliocene nationallicence Italy nationallicence Rendiconti Lincei Springer-Verlag 3/2(1992-06-01), 125-138 1120-6349 3:2<125 1992 3 12210 https://doi.org/10.1007/BF03002970 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF03002970 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Azzaroli A. Centro Interdipartimentale Museo di Storia Naturale e del Territorio Université degli Studi di Pisa Via Roma, 103 -56011, Calci, PI aut NATIONALLICENCE 773 0- Rendiconti Lincei Springer-Verlag 3/2(1992-06-01), 125-138 1120-6349 3:2<125 1992 3 12210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer