A rich Pliocene malacofauna has been recovered in a sandy bed of a section outcropping at Malverzana (Pisa, Tuscany) along the orographic right side of the torrente Cascina. The fossiliferous level belongs to sandy deposits representing the regressive phase of the Pliocene cycle in this area. The fossil assemblage consists of 125 taxa among which 67 gastropods, 54 bivalves and 4 scaphopods. Among the gastropods, 11 species (Gibbula semirotonda, Rissoa angulatacuta, Alvania cioppii, A. thalia, A. transiens, Pusilina nilae, Nassarius corrugatus, Gibberula sabatica, Bela megastoma, Odostomia conoastensis e Acteon semistriatus) are characteristic of the Pliocene time, and two of these (Rissoa angulatacuta e Odostomia conoastensis) are considered exclusive of Lower-Middle Pliocene. In this paper we figure, briefly describe and discuss Odostomia lukisii, Acteocina knockeri and Cylichnina crebrisculpta, for the first time recognized in Pliocene sediments along with a Melanella species very similar to the extant M. frielei that we prefer to left in open nomenclature. Moreover, we take also into account Gibbula semirotunda and Spaniorinus farnesinianus, both very rarely reported from Pliocene deposits. Characters allowing to distinguish described species from co-generic ones are pointed out.
Prima segnalazione di Odostomia lukisii Jeffreys, 1859, Acteocina knockeri (Smith E.A., 1872) e Cylichnina crebrisculpta Monterosato, 1884 nel Pliocene mediterraneo
RAGAINI, LUCA;
2007-01-01
Abstract
A rich Pliocene malacofauna has been recovered in a sandy bed of a section outcropping at Malverzana (Pisa, Tuscany) along the orographic right side of the torrente Cascina. The fossiliferous level belongs to sandy deposits representing the regressive phase of the Pliocene cycle in this area. The fossil assemblage consists of 125 taxa among which 67 gastropods, 54 bivalves and 4 scaphopods. Among the gastropods, 11 species (Gibbula semirotonda, Rissoa angulatacuta, Alvania cioppii, A. thalia, A. transiens, Pusilina nilae, Nassarius corrugatus, Gibberula sabatica, Bela megastoma, Odostomia conoastensis e Acteon semistriatus) are characteristic of the Pliocene time, and two of these (Rissoa angulatacuta e Odostomia conoastensis) are considered exclusive of Lower-Middle Pliocene. In this paper we figure, briefly describe and discuss Odostomia lukisii, Acteocina knockeri and Cylichnina crebrisculpta, for the first time recognized in Pliocene sediments along with a Melanella species very similar to the extant M. frielei that we prefer to left in open nomenclature. Moreover, we take also into account Gibbula semirotunda and Spaniorinus farnesinianus, both very rarely reported from Pliocene deposits. Characters allowing to distinguish described species from co-generic ones are pointed out.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
