Historical biogeography of the genus Rhadinaea (Squamata: Dipsadinae)

Multiple geological and climatic events have created geographical or ecological barriers associated with speciation events, playing a role in biological diversification in North and Central America. Here, we evaluate the influence of the Neogene and Quaternary geological events, as well as the climatic changes in the diversification of the colubrid snake genus Rhadinaea using molecular dating and ancestral area reconstruction. A multilocus sequence dataset was generated for 37 individuals of Rhadinaea from most of the biogeographical provinces where the genus is distributed, representing 19 of the 21 currently recognized species, and two undescribed species. Our analyses show that the majority of the Rhadinaea species nest in two main clades, herein identified as “Eastern” and “Southern”. These clades probably diverged from each other in the early Miocene, and their divergence was followed by 11 divergences during the middle to late Miocene, three divergences during the Pliocene, and six divergences in the Pleistocene. The ancestral distribution of Rhadinaea was reconstructed across the Sierra Madre del Sur. Our phylogenetic analyses do not support the monophyly of Rhadinaea. The Miocene and Pliocene geomorphology, perhaps in conjunction with climate change, appears to have triggered the diversification of the genus, while the climatic changes during the Miocene probably induced the diversification of Rhadinaea in the Sierra Madre del Sur. Our analysis suggests that the uplifting of the Trans‐Mexican Volcanic Belt and Chiapan–Guatemalan highlands in this same period resulted in northward and southward colonization events. This was followed by more recent, independent colonization events in the Pliocene and Pleistocene involving the Balsas Basin, Chihuahuan Desert, Pacific Coast, Sierra Madre Occidental, Sierra Madre Oriental, Sierra Madre del Sur, Trans‐Mexican Volcanic Belt, and Veracruz provinces, probably driven by the climatic fluctuations of the time.     

Systematics,palaeoecology and palaeobiogeography of the Neogene fossil sharks from the Azores (Northeast Atlantic)

The Azores Archipelago is a group of isolated islands located in the North Atlantic Ocean. One of these oceanic islands – Santa Maria – exhibits marine fossiliferous sediments of late Miocene/early Pliocene and also of Pleistocene age. Recent research provided new selachian fossil material, with three new records (Carcharias acutissima, Megaselachus megalodon, and Carcharhinus cf. leucas) increasing the number of fossil sharks reported from the Azores (Santa Maria Island) to seven species (Notorynchus primigenius, C. acutissima, Cosmopolitodus hastalis, Paratodus benedenii, Isurus oxyrinchus, M. megalodon, and C. cf. leucas). So far, no teeth of batoids or small sharks have been found despite the screen-washing of several sediment samples from Santa Maria. The Azorean Mio-Pliocene selachian fauna clearly differs from those described from sediments deposited on continental shelves, in which batoids and small benthic sharks (e.g., scyliorhinids) are usually well represented. During the late Miocene/early Pliocene, subtropical to warm-temperate seas were prevalent in the area of the Azores, as deduced from palaeontological, geological and isotopic data, all indicating a warmer climate than in the present.     

Cenozoic record of elongate,cylindrical, deep-sea benthic foraminifera in the North Atlantic and equatorial Pacific Oceans

In the late Pliocene–middle Pleistocene a group of 95 species of elongate, cylindrical, deep-sea (lower bathyal–abyssal) benthic foraminifera became extinct. This Extinction Group (Ext. Gp), belonging to three families (all the Stilostomellidae and Pleurostomellidae, some of the Nodosariidae), was a major component (20–70%) of deep-sea foraminiferal assemblages in the middle Cenozoic and subsequently declined in abundance and species richness before finally disappearing almost completely during the mid-Pleistocene Climatic Transition (MPT). So what caused these declines and extinction?In this study 127 Ext. Gp species are identified from eight Cenozoic bathyal and abyssal sequences in the North Atlantic and equatorial Pacific Oceans. Most species are long-ranging with 80% originating in the Eocene or earlier. The greatest abundance and diversity of the Ext. Gp was in the warm oceanic conditions of the middle Eocene–early Oligocene. The group was subjected to significant changes in the composition of the faunal dominants and slightly enhanced species turnover during and soon after the rapid Eocene–Oligocene cooling event. Declines in the relative abundance and flux of the Ext. Gp, together with enhanced species loss, occurred during middle–late Miocene cooling, particularly at abyssal sites. The overall number of Ext. Gp species present began declining earlier at mid abyssal depths (in middle Miocene) than at upper abyssal (in late Pliocene–early Pleistocene) and then lower bathyal depths (in MPT). By far the most significant Ext. Gp declines in abundance and species loss occurred during the more severe glacial stages of the late Pliocene–middle Pleistocene.Clearly, the decline and extinction of this group of deep-sea foraminifera was related to the function of their specialized apertures and the stepwise cooling of global climate and deep water. We infer that the apertural modifications may be related to the method of food collection or processing, and that the extinctions may have resulted from the decline or loss of their specific phytoplankton or prokaryote food source, that was more directly impacted than the foraminifera by the cooling temperatures.     

Late Neogene nannofossil biostratigraphy and paleoceanography of the northeastern Gulf of Mexico and adjacent areas

Two 305 m cored sections from the northwest Florida continental shelf contain a nearly complete record of late Neogene hemipelagic sedimentation. One of the sites, south and east of De Soto Canyon, is isolated from terrigenous sediment except for sediment transported in suspension. This site contains a continuous record from the late Miocene to the Recent. The second site, on the western rim of De Soto Canyon, is more expanded and continuous from the late Pliocene to the Recent. A hiatus separates the late Pliocene from the middle Miocene. Six prominent nannofossil biohorizons were recognized within the Pleistocene, seven within the Pliocene, and three within the Miocene; in addition one biohorizon marks the base of the Pleistocene and another the base of the Pliocene.Nearly all carbonate in the sediment is pelagic. Terrigenous detrital sedimentation was controlled by glacioeustatic sea level fluctuations during the Pleistocene, and sea level changes are probably responsible for fluctuations in the ratio of pelagic carbonate to clayey detritus in pre-Pleistocene sediments also. Carbonate content, coarse fraction percent, and relative abundances of environmentally sensitive nannoplankton species suggest important paleoceanographic changes in the northeastern Gulf of Mexico and adjacent areas. Fluctuations in the relative abundance of the solution-resistant coccoliths of the genusCyclococcolithus indicate that waters at a depth of 600–1000 m were more corrosive during the late Miocene than they are today. The decrease in carbonate dissolution during the late Miocene probably was a response to gradual constriction of the Central American passage and the consequent restriction of flow of corrosive water from the Pacific. Short term fluctuations in dissolution during the Pliocene and Pleistocene are related to climatic cycles.Productivity variations in the surface waters, recorded mainly by the relative abundance of small and large morphotypes of closely related coccolith species, indicate that productivity increased during the Pliocene, but the most dramatic change — a major oceanwide increase in productivity — occurred during the Pleistocene, during and just prior to the Jaramillo magnetic event about 0.9 m.y. ago. Surprisingly the late Miocene Messinian event did not leave a significant imprint in the northeastern Gulf of Mexico.     

Evolution of bird communities in the Neogene of Central Asia,with a review of the Neogene fossil record of Asian birds

A complete taxonomic review of Neogene birds of continental Asia is provided. To date, avifauna from the latter half of the Miocene and Pliocene of Central Asia (Mongolia and adjacent regions of Inner Asia) are most thoroughly investigated. Available data enable a reconstruction of successive replacement of Early and Middle Miocene avifaunas by communities of the Recent type. Middle Miocene avifaunas of Mongolia include a great number of extinct genera and species, many of which were widespread in Eurasia. Extant genera became dominant in the Late Miocene and taxa close to living species appear in the Late Pliocene fossil record. Late Pliocene communities of birds of Central Asia were complex in genesis, composed of Miocene relicts (Struthio), immigrants from the European regions of the Palearctic (phasianid Plioperdix), North American immigrants (Calcarius), and also autochthonous elements, the origin of which is apparently connected with the arid belt of Central Asia (diverse passerines).     

Late neogene biostratigraphy and stable isotope stratigraphy of a drilled core from the Gulf of Mexico

Late Neogene stable isotope stratigraphy and planktonic foraminiferal biostratigraphy have been examined in a high sedimentation rate core (E67-135, Shell Oil Co.) drilled at 725 m water depth in the De Soto Canyon, Gulf of Mexico. The 305 m core contains sections that are Late Miocene, Early Pliocene, Late Pliocene, and Quaternary in age, and is rich in well-preserved assemblages of planktonic foraminifera.A biostratigraphy has been established based on the ranges of 34 selected species of foraminifera. The core 3orrelates with sections from the Gulf of Mexico, the Caribbean Sea, and the subtropical North and South Atlantic Oceans using, as datums, the evolutionary appearances of Globorotalia miocenica Palmer and Globorotalia margaritae evoluta Cita, the extinction of Globorotalia miocenica and the first appearance of Globorotalia truncatulinoides (d'Orbigny).Oxygen and carbon isotope stratigraphy is based on analysis of the benthonic foraminifer, Uvigerina d'Orbigny. Isotopic trends are similar to those observed in the Pacific and Atlantic Oceans. From Early Pliocene to Late Pleistocene time, average δ¹⁸O values increase (2.42‰ to 3.36‰) and exhibit a wider range of values (0.71‰ in Early Pliocene compared to 1.65‰ in Late Pleistocene sediments), probably reflecting Late Neogene climatic deterioration. The ratio ${}^{13}\text{C}{}^{12}\text{C}$ decreases significantly by ?0.21‰ from the Late Miocene to the Early Pliocene. A decrease in δ¹³C is observed in other cores and is probably related to changing oceanic circulation patterns in Late Miocene time.     

The chronostratigraphic position of the Camping Francas section(Neogene of Tarragona,Spain)

The presence of Cirsotrema (s.s.) pumiceum (BROCCHI) and Chlamys (Manupecten) pesfelis (LINNE) in the section of Camping Francás (Province of Tarragona, Spain) suggests that the age of the deposits be changed from the upper Miocene (Tortonian) to the Pliocene. The change is of particular significance as the site is one of the classic localities of Pectinidae of the Neogene in North East Spain, and is type locality of Pecten (Flabellipecten) constisulcatus ALMERA & BOFILL.     

Paleocene-Pleistocene benthic foraminiferal evidence of major paleoceanographic events in the eastern South Atlantic (DSDP Site 525, Walvis Ridge)

Benthic foraminifers in the size-fraction greater than 0.073 mm were studied in 88 Paleocene to Pleistocene samples from Deep Sea Drilling Project Site 525 (Hole 525A, Walvis Ridge, eastern south Atlantic). Clustering of the samples on the basis of the 86 most abundant foraminifers (in total, 331 taxa were identified) allowed separating two major assemblage zones: the Paleocene to Eocene interval, and the Oligocene to Pleistocene interval. Each of these, in turn, were subdivided into three minor subzones as follows: lower upper Paleocene (approx. 62.4 to 57.8 Ma); upper upper Paleocene (56.6 to 56.2 Ma); lower and middle Eocene (55.3 to 46.8 Ma); upper Oligocene to middle Miocene (25.3 to 16 Ma); middle Miocene to Pliocene (15.7 to 4.2 Ma); and lower Pleistocene (0.4 to 0.02 Ma), with only minor differences with the previous zone. Some very abundant taxa span most of the column studies (Bolivina huneri, Cassidulina subglobosa, Eponides bradyi, E. weddellensis, Gavelinella micra, Oridorsalis umbonatus, etc.). Several of the faunal breaks recorded coincide with conspicuous minima in the specific diversity curve, thus suggesting that the corresponding turnovers signal the final stages of periods of faunal impoverishment. At least one major bottom-water temperature drop (as derived from δ¹⁸O data) is synchronous with a decrease in the foraminiferal specific diversity. On the other hand, a specific diversity maximum in the middle Miocene might be associated with a δ¹³C increase at approx. 16 to 12 Ma. Highest foraminiferal abundances (up to 600–800 individuals per gram of dry sediment) occurred in the late Paleocene and in the early Pleistocene, in coincidence with the lowest diversity figures calculated. The magnitude of the most important faunal turnover recorded, between the middle Eocene and the late Oligocene, is magnified in our data set by the large hiatus which separates the middle Eocene from the upper Oligocene sediments. Considerably smaller overturns occurred within the late Paleocene (in coincidence with changes in the specific diversity, absolute abundance of foraminiferal tests, and δ¹³C), and in the middle Miocene (in coincidence with a specific diversity maximum and a δ¹³C excursion). New information on the morphology and the stratigraphic ranges of several species is furnished. For all the taxa recorded the number of occurrences, total number of individuals identified and first and last appearances are listed.     

Regional patterns of evolutionary turnover in Neogene coral reefs from the central Indo-West Pacific Ocean

The Indo-Pacific is an area of intense ecological interest, not least because of the region’s rich biodiversity. Important insights into the origins, evolutionary history, and maintenance of Indo-Pacific reef faunas depend upon the analysis of faunal occurrences derived from detailed stratigraphic sections. We investigated Neogene origination and extinction patterns derived from a combination of new coral occurrences and previously published records from the central Indo-West Pacific Ocean (cIWP, Indonesia, Papua New Guinea and Fiji). Two faunal turnover events were observed. In the first, an increase in generic richness of Scleractinia from the cIWP during the middle Miocene (17–14 Ma) coincided with both large-scale sea level fluctuations and the great Mid-Miocene collision event. We raise the hypothesis that Mid-Miocene origination was facilitated by habitat and population fragmentation associated with tectonism and sea level fall. The second, subsequent, turnover event was characterized by an overall lowering of generic diversity throughout the late Miocene and Pliocene (7–3 Ma), and was followed by a pronounced pulse of extinction at the Pliocene–Pleistocene boundary (~2.6 Ma). With the exception of the onset of Pleistocene sea-level cycles and the onset of northern hemisphere glaciation around 2.5 Ma, which might explain increased extinction during this time interval, there are no tectonic, eustatic, climatic or oceanographic events that neatly coincide with this second episode of Neogene coral taxonomic turnover. Our results reveal a total of 62 genera, including synonyms, from the Miocene to the Pleistocene. Neither episode of turnover among coral genera is exactly coincident with turnover in the Atlantic thus regional environmental change is found to drive Neogene reef dynamics.     

Late Cenozoic sea level changes evidenced by ostracodes in the Pelotas basin,southernmost Brazil

Ostracodes recovered from sediments in seven onshore boreholes within the Pelotas basin, State of Rio Grande do Sul, indicate several continuous nearshore environments and at least four brief transgressive-regressive cycles are present. This interpretation is based on the distribution throughout upper Neogene and Quaternary sequences of species that characterize one or more biofacies depending on the borehole position in the basin. Bradleya pelotensis, Krithe coimbrai, Henryhowella kempfi and H. rectangulata are considered shelf-upper bathyal species whereas the shelf species are represented by Ambostracon crucicostatum, Argenticytheretta variabilis, A. laevipunctata, Brasilicythere reticulispinosa, Caudites posdiagonalis, Costa riograndensis, Coquimba bertelsae, C. tenuireticulata, Cytheretta punctata, Quadracythere eichlerae and Protocytheretta sp. Species with lagoon-estuarine shelf affinities include Callistocythere litoralensis, C. marginalis and Perissocytheridea kroemmelbeini whereas Cyprideis maxipunctata, C. mostardensis, C. posteroinflata, C. salebrosa and C. sparsopunctata represent a lagoon or estuarine environment, and Cypris cassinensis and Limnocythere sp. are freshwater species. Correlation of the ostracode biozones places the four maximum regressive events in the Late Pliocene and Pleistocene (1250-485 ka, 185 ka and 15 ka), whereas the maximum transgressive events occur in the Late Miocene and Pleistocene (1.6 Ma, 423–400 ka and 120 ka), in a barrier-lagoonal depositional system controlled by glacio-eustatic sea level changes.     

Biostratigraphic and paleoclimatic significance of a new Pliocene foraminiferal fauna from the central Arctic Ocean

A Pliocene benthic foraminiferal fauna containing a previously unknown species association was found in the basal section of a piston core collected from the crest of Northwind Ridge (NWR) in the central Arctic Ocean. The fauna is dominated by Epistominella exigua, Cassidulina reniforme, Eponides tumidulus, Cibicides scaldisiensis, Lagena spp., Cassidulina teretis, Eponides weddellensis, Bolivina arctica, and Patellina corrugata. The presence of Cibicides scaldisiensis in the assemblage and the occurrence of Cibicides grossus higher in the core are indicative of an early Pliocene age. The morphologically distinctive species Cibicidoides sp. 795 of McNeil (in press) which occurs in the NWR core sample was previously known only from Oligocene through Miocene deposits in the Beaufort-Mackenzie Basin of Arctic Canada. Ehrenbergina sp. A and Cibicidoides aff. C. sp. 795, also present in the core, are new and endemic to the Arctic late Miocene and early Pliocene. These species, and possibly others, are survivors of the late Miocene (Messinian) sea-level crisis, which caused a significant faunal turnover in the Arctic Ocean. The predominantly calcareous assemblage indicates deposition above the calcium carbonate compensation depth in an upper bathyal environment. Paleogeographic affinities for the bulk of the assemblage indicate probable connections between the Arctic and the North Atlantic Oceans, but the endemic species identify environmental differences or partial isolation of the western Arctic Ocean. The species association suggests a cold but milder paleoclimate than that which existed during Pleistocene glacial intervals.     

The Oldest Cranium of <Emphasis Type="Italic">Sinomastodon</Emphasis> (Proboscidea,Gomphotheriidae), Discovered in the Uppermost Miocene of Southwestern China: Implications for the Origin and Migration of This Taxon

The origin of the Old World brevirostrine gomphotheriid taxon Sinomastodon has been debated intensively. The discovery of the oldest known Sinomastodon cranium, reported herein, supports its endemic origin and contradicts the prevalent theory of its North America origin. The new cranium was discovered from the Shuitangba locality, southwestern China, and is dated at about 6.5–6.0 Ma, corresponding to the latest Miocene. The new specimen shows distinct characters from the other species of Sinomastodon and was therefore named Sinomastodon praeintermedius, sp. nov. Newly discovered, isolated Sinomastodon-like teeth from the upper Miocene to the lower Pleistocene of southwestern China and Southeast Asia indicate a long evolution of Sinomastodon endemically. Remains of this species are frequently accompanied by those of stegodontid species. These two groups may have had a similar migration route, invading northern China and Japan during the latest Miocene, and retreating or becoming extinct from the Palearctic realm by the end of the Pliocene. The migrations of proboscideans may have been sparked by major paleoenviromental changes, i.e., the strengthened summer monsoon beginning in the late Miocene (~7–8 Ma) and global cooling due to the expansion of ice sheets from the middle Pliocene to the early Pleistocene. The new finding reveals a close relationship of the early Pliocene fauna of northern China and the latest Miocene fauna of southwestern China, and thus provides novel insight into the origin and components of Pliocene fauna in northern China.     

Evidence for diversification of <Emphasis Type="Italic">Calophyllum</Emphasis> L. (Calophyllaceae) in the Neogene Siwalik forests of eastern Himalaya

Here, we report fossil leaves, woods, and pollen grains comparable to Calophyllum L. (mainly to Calophyllum inophyllum L. and Calophyllum polyanthum Wall. ex Choisy) of Calophyllaceae from the upper (Kimin Formation, late Pliocene-early Pleistocene), middle (Subansiri Formation, Pliocene) Siwalik sediments of the Arunachal sub-Himalaya, and lower (Gish Clay Formation of Sevok Group; middle to late Miocene) Siwalik sediments of the Darjeeling foothills, eastern Himalaya. Their presence indicates a warm and humid tropical environment in the region during the period of Siwalik sedimentation. Considering all records of Calophyllum, it is suggested that Calophyllum was a frequent forest element throughout the period of Siwalik sedimentation during the Neogene (Miocene time). At present, C. polyanthum grows in the eastern Himalaya, but C. inophyllum is totally absent from north-eastern regions suggesting differential adaptability of these taxa to changing ecoclimatic conditions. Distinct climate change in the area, possibly related to the Himalayan Orogeny during Miocene–Pleistocene times, might have caused the disappearance of C. inophyllum from the entire eastern Himalaya and north-east Indian plains and a move to littoral/coastal and swampy forests of India and other adjoining south-east Asian regions, Polynesia, and the east coast of Africa. The past global distribution of Calophyllum is also discussed, and it is suggested that India may have been its primary centre of origin. This is the first time Cenozoic fossil leaves Calophyllum siwalikum Khan, R.A.Spicer & Bera, sp. nov. comparable to C. inophyllum are described using the both macro- and micromorphological characters.     

Neogene planktonic foraminiferal biostratigraphy and evolution: Equatorial to subantarctic, South Pacific

Detailed planktonic foraminiferal zonations have been established for the Neogene (Latest Oligocene through present) in six DSDP sites in the South Pacific ranging from equatorial to subantarctic latitudes (48°S). Two basic zonal schemes are readily recognized: tropical and temperate. The tropical zonation is best developed in DSDP Site 289 and the temperate zonation in Sites 206, 207A and 284. Tropical and temperate zonations can be linked by a warm subtropical scheme in Site 208, because this sequence includes a mixture of tropical and temperate elements. A site located close to the Subantarctic Convergence (Site 281) contains a zonation largely of temperate character, but the present of cooler elements and some differences in biostratigraphic ranges have required a slightly different biostratigraphic scheme.Although two broad schemes are recognized, none of the biostratigraphic sequences are identical between any of the sites. This reflects differences in biogeography, evolution and diachronous extinction at various latitudes during the entire Neogene. Diachronism in biostratigraphic ranges continue to create difficulties in correlation across such wide latitudes.Our detailed work has required the establishment of new biostratigraphic zonations in certain parts of the Neogene sequence and modifications in some other parts. Otherwise, previously established schemes are followed as closely as possible. In the temperate region, a new zonation has been established for the Early Miocene to early Middle Miocene. For the remainder of the Neogene the zonation of Kennett (1973) has been largely used. The tropical zonation of Blow (1969) is employed in the equatorial Site 289, but with further subdivisions for Zones N4 and N17. For areas intermediate between tropical and temperate latitudes (Site 208), a modified Early Miocene zonation is established based on changes in tropical and temperate elements.The zonal schemes are established on taxa that exhibit both diachronous and isochronous ranges across the latitudes. Zones that are at least partly diachronous include the Globigerinoides trilobus and Globorotalia miozea Zones of Early Miocene age; perhaps the Globorotalia mayeri Zone (its base) of the Middle Miocene; the Globorotalia conomiozea Zone of the Late Miocene; and the Globorotalia crassaformis Zone of the Early Pliocene.A large number of datum levels are recognized based on first evolutionary appearances or extinctions. The most widely applicable datums are as follows: latest Oligocene — Globigerinoides F.A.; Early Miocene — Globoquadrina dehiscens, F.A., Globorotalia kugleri L.A., Catapsydrax dissimilis L.A. and Praeorbulina glomerosa F.A.; Middle Miocene — Orbulina suturalis F.A., Globorotalia peripheroacuta F.A., Fohsella lineage L.A., Globorotalia mayeri L.A.; Late Miocene — “Neogloboquadrina” continuosa L.A., Globoquadrina dehiscens L.A., Globorotalia cibaoensis F.A.; Early Pliocene — Globorotalia puncticulata F.A., Globorotalia margaritae F.A.; Early Pleistocene — Globorotalia truncatulinoides F.A. A number of other datums are identified which assist with correlation over more restricted latitudinal ranges.The evolution of most Neogene planktonic foraminifera is now well established for a wide range of water masses. Evolutionary lineages are primarily centered in the temperate and tropical regions. Tropical lineages have recently been reviewed by Srinivasan and Kennett (1981) and are not discussed in detail here. However, Sphaeroidinellopsis seminulina is now considered to have evolved directly into S. paenedehiscens during the Late Miocene and S. subdehiscens Blow is considered to be junior synonym of S. seminulina.A new evolutionary lineage is recognized in the warm subtropics (Site 208) whereby Globigerina woodi woodi gave rise to Globigerinoides subquadratus via Globigerina brazieri. The discovery of this lineage clearly demonstrates that Globigerinoides is a polyphyletic “genus”. Another major phylogenetic lineage is recognized within the temperate globorotaliids of Early Miocene age as follows: “N.” continuosa → Globorotalia zealandica incognita → G. zealandica zelandica → G. praescitula → G. miozea. Although parts of this lineage have been recognized earlier, the entire phylogeny has previously been underscribed.A new Early to Middle Miocene lineage is recognized in the subantarctic to temperate areas which involve a transition from Globorotalia praescitula to G. challengeri n. sp. via intermediate forms.Two major Neogene globorotaliid lineages — the Menardella of the tropics and Middle Miocene to Recent forms of Globoconella of the temperate areas — are both considered to have evolved from Globorotalia praescitula beginning in the Early Miocene. This evolution initially was restricted to temperate areas but has since separated into distinctly tropical and temperate phylogenetic elements.     

The circalittoral/bathyal paleocommunities in the Middle Pliocene of Northern Italy: The case of the Korobkovia oblonga-Jupiteria concava paleocommunity type

The Piacenzian section of Campore (Northern Italy) has been used to determine the paleoecological significance of the muddy upper bathyal mollusc associations of the Mediterranean Pliocene. By employing computer-based strategies (cluster and rarefaction analyses) a Korobkovia oblonga-Jupiteria concava paleocommunity type (KJpt) has been defined. The KJpt comprises a mosaic of local paleocommunities and paleocommunities whose taxonomic and trophic structures are mainly controlled by oxygen content, sediment accumulation rate, turbidity, and trophic resources. Comparison with mollusc coenoclines recognized in Northern Italy (Rio Merli and River Reno sections) suggests that the KJpt is bracketed between the deepest muddy circalittoral paleocommunities and the deeper bathyal Bathyspinula excisa-Austrotindaria pusio unit (preliminarily described for the Rio Merli section). The KJpt is very common in Northern Italy outcrops even though reported by previous authors with different names. We interpret this paleocommunity, which does not go beyond the Middle Pliocene, as the last evidence of an upper bathyal environment in the Neogene climatic-oceanographic regime of the Mediterranean.     

The fossil viperfish Chauliodus testa sp. nov. (Stomiiformes: Stomiidae) from the Neogene of western Sakhalin,Russia

The first fossil viperfish from Russia is recorded. It comes from the Neogene of Sakhalin Island and is assigned to a new species, Chauliodus testa (Pisces: Stomiidae). The new species is most similar to living Ch. macouni and differs from it in the completely ossifying cervical centra, the fewer cervical vertebrae, and the short predorsal distance. The finding of deep-sea viperfishes in the Miocene of western Sakhalin is evidence of independent development of the ichthyofauna in the Neogene of the Tartar Strait and Sea of Japan.     

Neogene phasianids (Aves: Phasianidae) of Central Asia: 2. Genera <Emphasis Type="Italic">Perdix,Plioperdix</Emphasis>, and <Emphasis Type="Italic">Bantamyx</Emphasis>

The phasianid genera Perdix, Plioperdix, and Bantamyx from the Neogene of Mongolia and Transbaikalia are reviewed. Based on published data and new material, the diagnoses of Late Pliocene Perdix margaritae Kurochkin and Plioperdix ponticus (Tugarinov) and Late Miocene Bantamyx georgicus Kurochkin are emended. It is shown that a tarsometatarsus from the Upper Miocene of the Pavlodar locality belongs to the genus Palaeoperdix rather than Palaeortyx, as was proposed in the previous studies. Small Neogene Asian phasianids are compared in detail with Neogene taxa from Europe and extant genera.     

Ostracodes et stratigraphie du néogène et du quaternaire méditerranéens

A stratigraphical chart of marine ostracoda from Lower Miocene to Recent is established. Selected species (approximatively 220) are those morphologicaly well characterized and known from different parts of the Mediterranean area. It appears that: • lower Miocene ostracodes are still poorly known; • specific diversity is high during the Tortonian and the Lower Messinian before the complete disappearance of marine Mediterranean species during the Upper Messinian évaporitic episodes; • during the early Pliocene, about half of the Upper Miocene marine species are reintroduced with the Atlantic waters; other species migrate for the first time in the Mediterranean Sea by the same way; • at the end of the Pliocene or at the beginning of the Pleistocene several species known in Mediterranean since the Middle Miocene or before, such as Cytherella sp. gr. transversa and Ruggieria tetraptera, as well some “nordic guests” such as Hemicythere villosa and Cythere lutea, appear. This work is an opportunity to confirme a Late Miocene age for the Neogene of Skyros (Aegean Sea), to assign the “Upper Pliocene” of Terquem to the Lower Pleistocene and to refute the existence of a pliocene psychrosphere.