Neogene astropectinids of Italy and extant forms of the Mediterranean Sea: a preliminary reappraisal

Astropectinidae represent the largest family of extant Asteroidea. Within this family, the genus Astropecten including more than two fifths of the total number of species. Although most astropectinids occur in cold waters, various species of Astropecten currently inhabit the Mediterranean Sea, namely: Astropecten aranciacus (Linnaeus, 1758); A. jonstoni (Delle Chiaje, 1827); A. irregularis (Pennant, 1777); A. spinulosus (Philippi, 1837); A. bispinosus (Otto, 1823), and A. platyacanthus (Philippi, 1837). These extant forms share several morphological characters with some fossil individuals referred to the same genus. Indeed, since the mid-XIX Century, several authors described complete astropectinids specimens from the Neogene marine sediment exposed in Central and Northern Italy. The earliest mentioned in literature is the holotype and only known specimen of Crenaster montalionis Meneghini 1852 from Montaione (FI). This specimen is currently subject of redescription and taxonomic re-evaluation by the authors of the present study. Cavara (1866) and Sacco (1893) illustrated A. bononiensis Cavara, 1866, A. cf. bispinosus Otto, 1823 and Astropecten sp. all from the Piacenzian outcrops of the Asti Province. Del Prato (1896) described the new species A. linati Del Prato, 1896 from the Mio-Pliocene deposits of the Parma Province as well as Astropecten sp. from the Langhian beds of Gombio (RE); this specimen was later referred by Borghi & Bajo Campos (2008) to Astropecten cf. forbesi Heller, 1858. Moreover, after a huge gap, Repetto & Bicchi (2013) described Astropecten cf. irregularis pentacanthus Delle Chiaje, 1825 from the muddy clay outcrops of Cherasco (AT).