Cryptoplacidae, H. Adams & A. Adams, 1858

Family Cryptoplacidae View in CoL H. & A. Adams, 1858

Genus Cryptoplax de Blainville, 1818 View in CoL

Type species. Chiton larvaeformis de Blainville in Burrow, 1815, by subsequent designation ( Gray 1821).

Distribution. Cryptoplax is known from the Miocene to the Recent, with a living distribution in tropical and temperate Indian and central western Pacific Oceans and the Red Sea (Gowlett-Holmes 2001). The fossil record extends back to the Miocene in Europe ( Laghi 1977; Dell’Angelo et al. 1999, 2016; Dulai 2001, 2005; Ruman & Hudáčková 2015), Melanesia ( Schwabe et al. 2008) and W. Pacific Islands ( Ladd 1966), the Miocene-Pliocene in Australia ( Cotton 1964) and the Pleistocene in the Red Sea ( Selli 1944, 1973; Dell’Angelo et al. 2020a).

Remarks. Three species of Cryptoplax are known from the Miocene of N. Italy and Paratethys: C. weinlandi Šulc, 1934 , C. lanceolatus Laghi, 1977 , and C. margitae Dulai, 2001 .

Chitonellus gigas O.G. Costa (1854), described upon an intermediate valve from the Pleistocene of Cannitello (Reggio Calabria), does not, in fact, belong to the genus Cryptoplax (= Chitonellus Lamarck, 1819 ); the generic attribution of Costa’s species remains uncertain (see below). The main characters of the species here discussed are reported in Tab. 24.