Messinian Lago-Mare deposits near the Strait of Gibraltar (Malaga Basin,S Spain)

A new stratigraphic unit (named LM unit) located at the base of the Pliocene marine succession in the eastern sector of the Malaga Basin has been distinguished. This unit is composed of two fining-upward sequences bounded by a discontinuity related to synsedimentary tectonic activity. Both sequences are made up of basal alluvial deposits overlain by subaquatic deposits. The lower sequence contains rich mollusc faunas characterized by bivalves Lymnocardiinae and Dreissenidae of Paratethyan origin, and non-marine gastropods, typical of oligo-low mesohaline shallow waters, and low diversified ostracod faunas of Paratethyan origin (Loxocorniculina djafarovi, Tyrrhenocythere pontica, Euxinocythere (Maeotocythere) praebaquana and Amnicythere propinqua) typical of low mesohaline waters. Alternances of monospecific ostracod assemblages made of Cyprideis agrigentina or oligotypic assemblages made of C. agrigentina and Loxoconcha spp. and richer assemblages made of L. djafarovi accompanied by several Amnicythere spp. and Camptocypria sp.1 characterize the upper sequence, pointing to more unstable environment affected by salinity and depth changes. Some samples collected from this upper sequence yielded rare, planktonic and benthic foraminifera, which could suggest the sporadic establishment of quasi-normal marine conditions in the westernmost Mediterranean during the deposition of this sequence. The palaeontological data and the palaeomagnetic results obtained in both the LM unit and the overlying Pliocene marine sediments restrict the age of the former to the post-evaporitic late Messinian. The age and the environmental conditions correlate these deposits with the Lago-Mare event occurring throughout the Mediterranean before the quick and widespread marine flooding of the Mediterranean at the beginning of the Pliocene.     

A gastropod from the tropical Atlantic becomes an established alien in the Mediterranean

We report the occurrence of an established population of the gastropod Mitrella psilla (Duclos, 1846), native on west African coasts of Mauritania, Senegal and Angola, on the shore of La Goulette, Bay of Tunis. The molluscan species of tropical West African affinity hitherto ascertained in the Mediterranean are not aliens, but have a native range which encompasses at least part of the Alboran Sea since historical times. Mitrella psilla appears therefore as the first instance of a mollusc with a tropical Atlantic origin being added to the Mediterranean fauna. The species was found near an important commercial harbour and is presumed to have been introduced by shipping.     

A review of European 'Mysella' species (Bivalvia, Montacutidae), with description of Kurtiella new genus

The type species of the genera Mysella Angas, 1877, RochefortiaVélain, 1878, Rochefortula Finlay, 1927 and AltenaeumSpaink, 1972 are illustrated and discussed. A new genus Kurtiellais introduced for ‘Mysella’ bidentata (Montagu,1803) and other European species currently placed in Mysella.These species display a unique diagnostic character state inhaving the cardinal platform deeply receding to house the internalligament, along with an array of more general montacutid traits.At the species level, diagnostic characters are given for thetype species K. bidentata, and for other included species K.ovata (Jeffreys, 1881), K. pellucida (Jeffreys, 1881), K. triangularis(Watson, 1897) and K. tumidula (Jeffreys, 1866), based mostlyon characters of the prodissoconch and on shell outline. Montacutasimillima Smith, 1892, from St Helena, is considered a juniorsynonym of K. pellucida. The loss of labial palps in K. tumidulais interpreted as a further derived character, which does notconflict with the generic placement in Kurtiella. (Received 28 August 2007; accepted 1 December 2007)     

A new genus and species of Asteriidae (Asteroidea; Echinodermata) from the Upper Cretaceous (Coniacian) of Angola,Africa

Afraster scalariformis n.gen. et sp., from the Upper Cretaceous (Coniacian) of Angola, southwest Africa, is assigned to the Pedicellasterinae, a subfamily of the Asteriidae. An associated foraminiferal fauna is dominated by planktic species; also present are lagenids that are indicative of a shelf setting. The subfamily Pedicellasterinae is peculiar in that only two rows of podia are present, rather than the four typical of the family. Intimate association ofAfraster with oysters suggests the predatory habits typical of modern asteriids; general arm and disk arrangement also suggest such a behavior.Afraster is the first recorded fossil asteroid from Angola.