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Late Miocene brackish Loxoconchidae (Crustacea, Ostracoda) from Italy.
No full textThe Family Loxoconchidae Sars 1925 includes over 800 fossil and extant species that mainly inhabit littoral and sublittoral marine environments. Only few living species (i.e. Loxoconcha elliptica Brady, Elofsonia baltica (Hirschmann), Hirschmannia viridis (Müller), Sagmatocythere pennata (Schornikov), Loxoconchissa (Loxocaspia) immodulata Schornikov) can withstand brackish waters.During Late Miocene, in the Paratethyan domain wide brackish basins developed and numerous Loxoconchidae adapted to the decreased salinity. Beside several species pertaining to the genus Loxoconcha, other species have been referred to the genera Loxocorniculina, Loxoconchissa s.s. and Loxoconchissa (Loxocaspia). In the Italian brackish basins developed during Late Miocene it is possible to recognise the presence of all these genera: Loxoconcha and Loxocorniculina are mainly documented in the latest Messinian lago-mare biofacies [i.e. Loxoconcha eichwaldi Livental, Loxoconcha muelleri (Mehés), Loxoconcha rhombovalis Pokorny and Loxocorniculina djafarovi (Sneider in Suzin)]; on the contrary Loxoconchissa s.s. and Loxoconchissa (Loxocaspia) seem to be confined to the Late Tortonian-early Messinian brackish basins of Tuscany (Volterra-Radicondoli, Cinigiano-Baccinello and Velona Basins) and are represented by new species.A re-definition of the genus Loxoconchissa s. l. on the base of the hinge and of the sexual dimorphisms is presented in this paper and its geographic and stratigraphic distribution are discussed
The genus Cyprideis Jones, 1857 (Crustacea, Ostracoda) in the Neogene of Italy: a geometric morphometric approach.
No full textAs a result of the use of geometric morphometrics, multivariate statistics and classical morphological observations the authors propose a
taxonomic revision of the Neogene Italian Cyprideis species. On this basis, the Cyprideis valves collected in Tortonian, Messinian and Pliocene
brackish deposits of Italy are referred to 12 species, six of which are new: Cyprideis alexandri nov. sp., Cyprideis arvedoi nov. sp., Cyprideis
lepianensis nov. sp., Cyprideis rooki nov. sp., Cyprideis strollae nov. sp., and Cyprideis toscana nov. sp. Some species are rather widespread in the
Italian Peninsula (Cyprideis ruggierii Decima and Cyprideis crotonensis Decima) or even in the whole Palaeomediterranean (Cyprideis agrigentina
Decima and Cyprideis anlavauxensis Carbonnel). For C. ruggierii, C. agrigentina and C. crotonensis, a phyletic relation is suggested. The new
species are confined both geographically and stratigraphically in several Tuscan athalassic brackish basins, suggesting endemic speciation similar
to those occurring in ancient lakes
New species of Mediocytherideis (Ostracoda, Mediocytherideisinae) in the brackish Messinian of Italy
No full textIn questo lavoro vengono studiati il genere Mediocytherideis Mandelstam, 1956 con i suoi sottogeneri Mediocytherideis s.s. e M. (Sylvestra) Doruk, 1973 e vengono fornite, per entrambi, le diagnosi emendate. Vengono istituite sei nuove specie: Mediocytherideis (Sylvestra) etrusca nov. sp., Mediocytherideis (Sylvestra) fossata nov. sp., Mediocytherideis (Sylvestra) ornata nov. sp., Mediocytherideis (Sylvestra) punctata nov. sp., Mediocytherideis (Sylvestra) sulcata nov. sp. e Mediocytherideis (Sylvestra) tetrafoveolata nov. sp., rinvenute nei sedimenti messiniani salmastri dei bacini di Volterra-Radicondoli e di Velona (Toscana, Italia centrale). Inoltre, a causa dello scarso materiale rinvenuto, sono state lasciate
in nomenclatura aperta tre forme di Mediocytherideis s.l. provenienti dai sedimenti salmastri messiniani del bacino di Velona, dalla sezione del cimitero di Taranta Peligna (Montagna della Majella, Italia centrale) e dalla sezione Trave (Ancona, Italia centrale). Viene effettuata, inoltre, una revisione delle specie di Mediocytherideis s.l. note fino ad oggi in letteratura, ponendo particolare attenzione alla loro distribuzione stratigrafica e, sulla base di questi dati, vengono discusse l’origine e la distribuzione stratigrafica e paleobiogeografica del genere. Il database mostra che sia Mediocytherideis s.s. sia M. (Sylvestra) appaiono più o meno contemporaneamente nell’area mediterranea
e in quella paratetidea durante il Serravalliano, quando i due paleodomini non erano ancora separati. Dopo la chiusura della connessione tra Mediterraneo e Paratetide, avvenuta durante il Serravalliano superiore, Mediocytherideis s.l. continuò ad evolversi, con differenti specie, nelle due paleobioprovince. Nella Paratetide le specie di Mediocytherideis s.l. furono sempre caratteristiche di ambienti salmastri o, nei primi momenti della storia evolutiva del genere, di ambienti marini poco profondi stressati; nel Mediterraneo, al contrario, fin dalla sua prima comparsa il genere diede origine a differenti specie adattate o ad ambienti marini poco profondi o ad ambienti salmastri. Sfortunatamente, le conoscenze troppo frammentarie sulle specie di Mediocytherideis s.l. rendono impossibile definire il centro di origine del genere. Allo stesso tempo, è impossibile stabilire se le specie salmastre mediterranee di Mediocytherideis s.l. si originarono da uno stock mediterraneo o da forme salmastre paratetidee migrate verso ovest attraverso la dispersione passiva.The genus Mediocytherideis Mandelstam, 1956 with its subgenera Mediocytherideis s.s. and M. (Sylvestra) Doruk, 1973 are here revised and the emended diagnosis of the two subgenera are given. Six new species have been introduced: Mediocytherideis (Sylvestra) etrusca nov. sp., Mediocytherideis (Sylvestra) fossata nov. sp., Mediocytherideis (Sylvestra) ornata nov. sp., Mediocytherideis (Sylvestra) punctata nov. sp., Mediocytherideis (Sylvestra) sulcata nov. sp. and Mediocytherideis (Sylvestra) tetrafoveolata nov. sp., coming from the Messinian brackish sediments of the Volterra-Radicondoli and Velona basins (Tuscany, central Italy). Three more taxa are described, left in open nomenclature, coming from the Messinian brackish sediments of the Velona Basin, the Taranta Peligna cemetery section (Majella Mt.,
central Italy) and the Trave Section (Ancona, central Italy).
An overview of the known Mediocytherideis s.l. species is given and the stratigraphic distribution and palaeobiogeography of this genus is discussed. The database shows that both Mediocytherideis s.s. and M. (Sylvestra) appear, more or less at the same time, either in the Mediterranean and in the Paratethys regions during Serravallian, a time interval in which these two palaeodomains were not yet divided. After the closure of the Mediterranean-Paratethys connection, occurred during the late Serravallian, Mediocytherideis s.l. continued to spread in each bioprovinces: in the Paratethys it is characteristic of brackish environments or, at least at the very beginning of its evolutive history, of shallow stressed marine environment; in the Mediterranean, on the contrary, since its appearance the genus gave rise to different species adapted to shallow marine environment or brackish environment. Unfortunately the too much-fragmented knowledge on Mediocytherideis s.l. species prevents the recognition of the centre of origin of the genus. Similarly, it is impossible to establish whether the brackish Mediterranean Mediocytherideis s.l. evolved from a Mediterranean stock or from Paratethyan brackish species migrated westwards by passive dispersal
Resistenza genetica ai nematodi G.I. degli ovini: ricerca dei Quantitative trait locus (QTL) sul cromosoma 3.
No full textOccurrence of Vestalenula (Darwinuloidea, Ostracoda) in the Neogene of Italy, Crete and Serbia, with the description of one new species
No full textThe morphology of fossil remains of Vestalenula (Darwinuloidea, Ostracoda) from Crete
(Greece), Serbia and Italy were analysed using morphometric valve variability analysis. Three new species
were distinguished and described, Vestalenula angulata n. sp., Vestalenula longissima n. sp. and Vestalenula
pliocenica n. sp., and represent the first record of this genus in the Neogene of Italy and Serbia. Vestalenula
angulata n. sp. was recorded from the early Messinian of Tuscany, Italy (Baccinello and Velona Basins),
Vestalenula longissima n. sp. was collected in the Upper Pliocene (Gelasian) sediment core drilled in the
Sabina area (Latium, Italy), and Vestalenula pliocenica n. sp. was collected from the Early Tortonian of
Vrysses (Rethymnon Basin, Crete), from the lower Messinian deposits of the Velona Basin (Tuscany,
Italy), in the Late Pliocene of the Paludinian Beds (Middle Danube Plain) and Mazgoš deposits (Serbia),
and in the Upper Pliocene deposits of the Sabina area (Latium, Italy). Despite the freshwater character of
most living species of Vestalenula, the fossil species here analysed were found associated with halotolerant
forms, showing they could also withstand oligohaline conditions
Late Miocene palaeoenvironmental evolution of the Baccinello–Cinigiano Basin (Tuscany, central Italy) and new autoecological data on rare fossil fresh- to brackish-water ostracods
No full textThis paper reports the results of palaeoecological analyses on fossil ostracod communities of the Tortonian and
Messinian deposits cropping out in the Baccinello–Cinigiano Basin, a Tuscan (central Italy) post-collisional
continental basin. Through multivariate analyses, such as Cluster Analysis (UPGMA) and Detrended Correspondence
Analysis (DCA), several physico-chemical variations in the water body have been recognised. The more
ancient (Middle–Late Tortonian) lacustrine environmentwas characterised by a shallowproximal and a deep distal
facies with oligo-mesohaline waters. During this stage, the salinity of the lake water was controlled by the
dissolution of Triassic evaporites buried at shallow depth in the basin. Instead, the subsequent lower Messinian
fluvio-lacustrine environment was characterised by shallow freshwater habitats with variable water flow
conditions. During the uppermost lower Messinian, the lake was deep and contained brackish water again. These
reconstructions add newinformation on the variability of several ecological parameters such as depth, salinity and
water flowconditions and help to clarify the autoecology of poorly known fossil ostracods.Within the fossil genus
Tavanicythere, the species Tavanicythere irregularis, Tavanicythere parva and Tavanicythere sp. Q are adapted to deep
and saline waters, Tavanicythere lepida is a shallow and less saline water inhabiting species, while Tavanicythere
nodosa occupies an intermediate position with respect to palaeodepths and palaeosalinities. Within the genus
Loxoconchissa, Loxoconchissa (Loxoconchissa) kinoi and Loxoconchissa (Loxocaspia) tuberosa are characteristic of an
oligohaline and deep environment, while Loxoconchissa (Loxocaspia) nuda and Loxoconchissa (Loxocaspia) sp.1 are
more halophile species. Potamocypris gracilis is a polyrheophilic and rather profundal species that can tolerate
shallower depths. Paralimnocythere bicornis is a freshwater to slightly halophylic and reophobic species. Vestalenula
sp. is one of the few known Vestalenula species that can withstand slightly saline waters
Parathethyan ostracod immigrants in Italy during Late Miocene.
No full textDuring Serravallian, the emersion of the Carpathians and of the Alpine foreland domain closed the northern connection between the western and the eastern Tethys. In the late Miocene this latter became subdivided into several basins (Vienna Basin, Pannonian Basin, Dacic Basin, Ponto-Euxinic Basin and Caspian-Aral Basin) which, due to the freshwater input from several important rivers, were progressively characterised by brackish waters. The connection via the present Dardanelli straight was still open but the different salinity between western and eastern Tethys represented an ecological barrier, preventing the faunistic exchanges and causing the onset of two different Late Miocene bioprovinces: the Paleomediterranean bioprovince to the west and the Paratethyan bioprovince to the east.Notwithstanding the Late Miocene isolation of Paleomediterranean from Paratethys, during Late Tortonian-early Messinian it is possible to recognise in Italy few brackish and freshwater ostracods with Paratethyan affinity. The palaeogeography of the area prevents to suppose a normal aquatic migration, and, indeed, the distribution of several Paratethyan genera seems disjuncted. In this case, only a passive dispersal by aquatic birds can be claimed. Paratethyan genera transported in Italy are Camptocypria (Sirmiella), Bakunella, Propontoniella, Labiatocandona, Zalanyiella (all included in the Subfamily Candoninae), Loxoconchissa s.s. and Loxoconchissa (Loxocaspia), included in Family Loxoconchidae and Amnicythere (and may be Chartocythere and Mediocytherideis) included in Family Leptocytheridae.During the latest Messinian lago-mare event, the closure of the Atlantic-Mediterranean connection and the subsequent humid global climate phase caused a salinity lowering of the Paleomediterranean waters. The ecological barrier between Paleomediterranean and Paratethys was disrupted and an important contingent of Paratethyan ostracods migrated westwards colonising the Paleomediterranean, whose endemic fauna was severely impoverished by the Messinian salinity crisis and the following water dilution. The Italian (and Paleomediterranean) latest Messinian lago-mare deposits are characterised by Paratethyan species such as Caspiocypris pontica, Lineocypris cf. L. fossulata, Lineocypris cf. L. hodonensis, Pontoniella pontica, Zalanyiella venusta, Amnicythere accicularia, Amnicythere anormalis, Amnicythere cellula, Amnicythere costata, Amnicythere idonea, Amnicythere pontica, Amnicythere lata, Amnicythere litica, Amnicythere multituberculata, Amnicythere palimpsesta, Amnicythere propinqua, Amnicythere cf. A. rosalinae, Amnicythere subcaspia, Euxinocythere (Maeotocythere) praebaquana, Euxinocythere (Maeotocythere) bosqueti, Loxoconcha (Loxoconcha) eichwaldi, Loxoconcha (Loxoconcha) muelleri, Loxoconcha rhombovalis, Loxoconcha cf. L. schweyeri, Loxocorniculina djafarovi, Pseudocythere limata, Cytherura pyrama, Tyrrhenocythere ruggierii, Tyrrhenocythere pontica
Livelli ematici di Glucosio, NEFA e Insulina in pecore sarde al pascolo con differenti disponibilità di erba e concentrato.
No full textParatethyan faunas in the Tortonian succession of the CARG-FVG S6 “Col Vergnal” drilling (Friuli, NE Italy)
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