Bollettino SPI Vol. 43 - Issues 1-2, 3
Issues 1-2
Published in November 2004
- Benson R.H. (2004)
Giuliano Ruggieri in the 60’s and 70’s and the Messinian Salinity Crisis: from an American friend’s point of view
pp. 1-9
The influence of Giuliano Ruggieri on the ultimate definition of the Miocene/Pliocene boundary and unraveling of the history of the Messinian Salinity Crisis was one of the tenacity with which he argued far the general eradication of the marine faunas throughout the Mediterranean region and their replacemmt by ostracode faunas typical of paratethyan lakes. Although he recognized a sharp contrast between marine faunas of the late Miocene and those of the earliest Pliocene, it was his aid to others, including the present author, which led to the identification of the sudden establishment of oceanic conditions in the Zanclean, and the continued presence of deep basins. This is a story about that influence… and as well abow Giuliano, the scientist of his time as I saw him.
- Aiello G. & Szczechura J. (2004)
Middle Miocene ostracods of the Fore-Carpathian Depression (Central Paratethys, southwestern Poland)
pp. 11-70
The taxonomy of marine ostracod assemblages from Upper Badenian (Serravallian) sediments of Upper Silesia Basin (Fore-Carpathian Depression, southwestern Poland) has been studied. Twenty-two samples, recovered in the Gliwice 21 borehole, yielded 102 species belonging to 63 genera. Of these species, 56 have been previously described, 8 are tentatively referred to known species; 18 species and 2 subspecies are described as new, the latter are Callistocythere gliwicensis sp. nov., Cytherois ruggierii sp. nov., Cytheroma bonaducei sp. nov., Cytheropteron nadezdae sp. nov., Cytheropteron sagittaeferrum sp. nov., Hemiparacytheridea tuber sp. nov., Kunihirella viatrix sp. nov., Loxoconcha quadrifenestrata sp. nov., Microcythere panis sp. nov., Microcytherura (Microcytherura) everriculum sp. nov., Microcytherura (Tetracytherura) dianae sp. nov., Paracytheridea depressa G. W. Müller 1894 coaequata subsp. nov, Paracytherois nealei sp. nov., Sagmatocythere raiai sp. nov., Sagmatocythere scrupea sp. nov., Semicytherura aviculaecaput sp. nov., Semicytherura furcilla sp. nov, Semicytherura xscripta sp. nov, Swainocythere miniscula (Ruggieri, 1977) anae subsp. nov., and Typhlocythere perparvula sp. nov. Further 7 species are left in open nomenclature and 11 with affinitive status. Stratigraphic and areal distributions of the taxa have been reported. Seven genera, i.e. Hemiparacytheridea, Kunihirella, Loxoconchidea, Rimacytheropteron, Ruggieriella, Swainocythere and Typhlocythere have been recorded for the first time in the Central Paratethys.
- Aiello G., Coimbra J.C. & Barra D. (2004)
Ruggiericythere, a new shallow marine ostracod genus from Brazil
pp. 71-90
The new ostracod genus Ruggiericythere (Hemitytheridae Puri, 1953) is described and illustrated from recent sediments of the Brazilian continental shelf. Seven species assigned to the new genus are discussed and figured: four of these, i.e. R. perspicua, the type-species. R. batistae, R. purperae and R. vixalata, are described as new species; Ruggiericythere dimorphica (Whatley, Moguilevsky, Chadwick, Toy & Ramos, 1998) has been previously described from the Southwestern Atlantic; two species, Ruggiericythere sp. 1 and Ruggiericythere sp. 2, are left in open nomenclature due to paucity of material. Analysis of 934 samples, recovered on the Brazilian shelf, provided data on the geographical and bathymetric distribution of Ruggiericythere. In the study area the genus extends from the coast of Bahia State (17° 59′ S) to the Uruguayan continental shelf (35 ° 14′ S), a region which mainly under the influence of subantarctic waters. Previous records show that Ruggiericythere can be found as far South as the Northern Argentinean continental shelf (41° 52′ S). The depth distribution of this shallow genus ranges from 3.5 to 165 m.
- Arbulla D., Pugliese N. & Russo A. (2004)
Ostracods from the National Park of La Maddalena Archipelago (Sardinia, Italy)
pp. 91-99
Detailed descriptions of their soft anatomies are provided for two Ostracoda recorded from the Bay of Naples: Rectobuntonia subulata (Ruggieri, 1954) and Cytherella vulgatella Aiello, Barra, Bonaduce & Russo, 1996. Additionally, the soft parts of Procytherideis Ruggieri, 1978 are indicated by description of P. subspiralis (Brady, Crosskey & Robertson, 1874); and those of Pseudocytherura calcarata (Seguenza, 1880) and Paracytheridea depressa Müller, 1894 are also described, with discussion on Paracytherideidae. Finally the male soft anatomy of’ Polycopsis compressa (Brady & Robertson, 1869) is detailed with discussion on the family Polycopidae and the diagnosis of Chavturopsis new genus, having the type species Chavturopsis pacifica (Chavtur, 1977).
- Bonaduce G. & McKenzie K.G. (2004)
Soft anatomies of some Ostracoda from the Bay of Naples described by Professor Giuliano Ruggieri and other workers
pp. 101-112
The influence of Giuliano Ruggieri on the ultimate definition of the Miocene/Pliocene boundary and unraveling of the history of the Messinian Salinity Crisis was one of the tenacity with which he argued far the general eradication of the marine faunas throughout the Mediterranean region and their replacemmt by ostracode faunas typical of paratethyan lakes. Although he recognized a sharp contrast between marine faunas of the late Miocene and those of the earliest Pliocene, it was his aid to others, including the present author, which led to the identification of the sudden establishment of oceanic conditions in the Zanclean, and the continued presence of deep basins. This is a story about that influence… and as well abow Giuliano, the scientist of his time as I saw him.
- Bossio A., Ciampo G. & Dall’Antonia B. (2004)
Quaternary environmental evolution of the Venice area based upon ostracod assemblages
pp. 113-122
The cores VE-1 and VE-1bis were drilled on Isola Nuova del Tronchetto (Venice). They are, in all, about 950 m long. Qualitative and quantitative analysis of ostracod assemblages from the interval depth of 917.70 to 5.10 rn were carried out with the aim to study environmental and sedimentary history of this sector of the Venice lagoon. The first occurrence of Hyalinea baltica (Emilian Stage) at 907.98 m and of Globorotalia truncatulinoides excelsa (Sicilian Stage) at 768.99 m, together with ostracods species (i.e. Palmoconcha turbida) allowed to better specify the age of the lower interval of the core. Despite the paucity of the ostracod fauna (many samples are barren), mostly related to the widespread turbidite deposition, it was possible to reconstruct the evolution of the lagoon from the offshore marine environment (maximum inferred depth value of about 190 m) during the Lower Pleistocene to the actual laguna.
- Ciampo G. (2004)
Measurement of the uplift of the La Starza Marine Terrace (Pozzuoli-Italy) by ostracod assemblages
pp. 123-128
The uplift of the marine terrace of La Starza (Pozzuoli – South Italy) has been calculated on the basis of ostracod assemblages. The very swift uplift occurred between 8 and 4.5 kyr BP and it lifted the terrace by at least 68 m.
- Dall’Antonia B., Bossio A. & Guernet C. (2004)
Short taxonomic notes on deep-sea ostracods from the Massignano GSSP for the Eocene/Oligocene boundary (Central Italy)
pp. 129-139
Deep-sea Ostracoda from the Massignano GSSP for the Eocene/Oligocene boundary (Central Italy) are discussed from a systematic point of view. Apart from the genus Krithe, which could not be specifically identified owing to the poor preservation of the fauna, a total of 17 species belonging to 13 genera (one of which remains undetermined) were identified. Previously known species include Agrenocythere ordinata (Deltel), Argilloecia angulata (Deltel), Argilloecia sp. 1 (=Argilloecia sp. /293 Kollmann), Dutoitella eocenica (Benson), Legitimocythere presequenta (Benson), and Trachyleberidea pisinensis (Kollmann). Remaining taxa are left in open nomenclature or assigned to informal group. Taxonomic comments, SEM illustrations and a fundamental synonymy are provided.
- Dall’Antonia B., Ciampalini A., Michelucci L., Zanchetta G., Bossio A. & Bonadonna F.P. (2004)
New insights on the Quaternary stratigraphy of the Livorno area as deduced by borehole investigations
pp. 141-157
This paper reports the main results af an integrated study of 15 boreholes drilled in the subsurface of the Livorno surroundings. Despite this area is one of the most extensively studied of the Coastal Tuscany (Central Italy), especially for the well-known Eutyrrhenian “panchina” deposits (beach rocks), the subsurface stratigraphy is still imperfectly known. The present study focused on an area which comprises the city of Livorno, located on the eustatic Livorno Terrace and the southernmost sector of the Pisa Plain. These two domains are separated by the “Gronda dei Lupi” erosional scarp. Analyses performed included lithological-sedimentological observations, macro-micropalaeontological investigations, and radiocarbon dating. Stratigraphical interpretation of the 15 investigated boreholes allowed to distinguish 7 main lithostratigraphic units, some of which can be correlated with formations outcropping in North-Western Tuscany. Particularly, in the Livorno Terrace domain we have been able to confirm the presence below the Eutyrrhenian “panchina” layer of a relatively thick marine succession belonging to the Santernian-Emilian cycle. In addition. the Lower Pleistocene succession appears to include two units so far unrecognized in the area. Specifically, we identified brackish sediments referable to the regressive phase of the Santernian-Emilian cycle and a second marine Lower Pleistocene cycle, which can be assigned to the Sicilian on the basis of both ostracod faunas (common occurrences of Aurila puncticruciata) and calcareous nannofossils (“small Gephyrocapsa Zone”). Finally, in a single borehole drilled in proximity of the “Gronda dei Lupi” scarp, we recorded nearshore to transitional sediments, which need further investigations, but might likely represent a cycle of probable Upper Pleistocene age (younger than the Eutyrrhenian “panchina” layer). In the Pisa Plain domain, we recorded brackish-continental sediments (with lower levels of probable Upper Pleistocene age), which are truncated by sands referable to the Versilian transgression. Historical coastal deposits close the succession. On the whole, achieved data allowed to refine the Quaternary stratigraphy of the Livorno surroundings and suggest that this area underwent a more complicated stratigraphical history than previously recognized.
- D’Arpa C. & Ruggieri G. (2004)
Pliocene Ostracofauna of the Altavilla section (Altavilla Milicia, Sicily). Systematic remarks
pp. 159-180
The studied Ostracofauna comes from a single level of the most classical Sicilian Pliocene section, located on the right bank of the Milicia River, in the surroundings of the town of Altavilla in the province of Palermo. The studied section is formed by a fifty metre thick sequence of yellow sands with Amphistegina, showing uneven stratification with some more cemented isolated sandstone layers.
Calcareous nannofossils have allowed referring the sampled level as MNN 16 b-17/-Discoaster pentaradiatus Zone, and dating it as upper Piacenzian.
The studied ostracofauna comprises abundant, well-preserved material corresponding to 150 species including 31 new taxa. Eighty species have been already described and illustrated in three former studies by the present authors. The remnant new species. corresponding to genera Sagmatocythere, Paracytheridea, Cytherura, Semicytherura, Hemicytherura, Eucytherura, Cytheropteron and Paradoxostom, are described for the first time in this paper.
The occurrence of some particular species in this sequence has some paleobathimetric implications. Several species of this association are typical of shallow marine environment with vegetation. Most of other species in turn are typical of more open marine conditions, in sub-littoral facies. Some 70% of described taxa belong to such genera as Incongruellina, Tegmenia, Ruggieria, Mutilus, and Paijenborchella, which are no longer typical of Mediterranean Province.
- Galoukas S. & Danielopol D.L. (2004)
Taxonomic diversity of Late Cenozoic Cytheroidea (Ostracoda) from Cyprus Island
pp. 181-199
Late Cenozoic ostracod assemblages of south-western Cyprus offer a unique opportunity to document the faunal changes which occurred at various marine sites during the Upper Miocene-Lower Pliocene around the island coast. Previously, biostratigraphic data based on Ostracoda fauna obtained from Kalavasos and Nicosia Formations pointed to strong environmental changes that presumably are related to the so-called “Messinian Salinity Crisis” event. This information is compared to those restricted on 10 samples belonging to three sections, Amargeti, Polemi, and Mari and the changes in the Cytheroidea taxocenosis documented through a qualitative analysis of the ostracod material. For the first time two indices diversity, the Average Taxonomic Distinctness (called Delta+ index) and the Variation of Taxonomic Distinctness (the Lambda+ index) are used for the characterisation of changes in fossil ostracod assemblages. Information on Cytheroidea assemblages was used for three levels of the Linnaean hierarchy (the species, the genus, and the family), following the Clarke and Warwick (1998, 2001) algorithms for the computation of the taxonomic diversity . The results suggest the occurrence of stressful ecological conditions in the coastal environment during a short period of time, more precisely during a lowering of the marine water level where the sampling area transformed in an environment with brackish lagunar conditions, followed later-on by the reversal to an eumarine situation. It is concluded that the Clarke and Warwick taxonomic diversity indices are useful descriptors for palaeoecological changes and should be more widely used.
- Keen M.C. (2004)
The origin of the modern tropical West African marine Ostracod Fauna with a description of the Ruggieriini n. tribe
pp. 201-216
Many species and genera found today along the West African coast and shelf stretching from the Niger Delta northwards to Mauritania have their origins in a great faunal renewal that took place in the late Oligocene and early Miocene. The hemicytherids are absent from the Miocene, giving the faunas a very different appearance from contemporaneous North African, American, and Mediterranean faunas. Later recruitment to the West African faunas came from the Americas and the northern warm-water Atlantic during the Pliocene and Quaternary, including the hemicytherids. A new tribe of the Trachyleberididae, Ruggieriini, is described, with new genera Tetraruggieria, Afroruggieria, Nigeriruggieria, and Leoniruggieria.
- Mazzini I. (2004)
Quaternary benthic Ostracoda from the Tasman Sea: distribution patterns within circumpolar deep-waters
pp. 217-224
Benthic Ostracoda were recovered from box-core samples collected during the cruise SO 136 of the German R.V. Sonne in the Tasman Sea and Southern Ocean (SW Pacific sector). The distribution of 33 ostracod genera (73 species) identified in 15 sediment samples is analysed in contact with the Circumpolar Deep Water (CPDW).
Q-mode cluster and detrended correspondence analyses of the data partially support the observations made by previous authors that ostracod genera have specific thresholds controlled by water mass characteristics. In fact, the subdivision of the CPDW in three distinct units is well recorded by the ostracod assemblages. Concerning epi-faunal genera such as Bradleya and Poseidonamicus, temperature and dissolved oxygen play a main role in determining specific generic thresholds. Instead, the parameters controlling the distribution of the infaunal genus Krithe are not clear. Within the sediment, the distribution pattern could be driven mostly by the amount of organic matter, oxygen supply and sediment grain size.
At the specific level, R-mode detrended correspondence analysis clearly shows that distribution patterns must be driven by other factors, covering the influence of the water-mass characteristics. Bottom topography, deep ocean currents and flux of organic carbon interplay with the water-mass characteristics, thus creating a complex network of ecological gradients. Within each of the three main communities identified through the Q-mode analysis, the species-specific thresholds are not identical and often the range of the ecological gradients of the most common species does not include those of the rare species. Most likely, dynamics of co-occurring species take place and there involve Ostracoda and other benthic species belonging to the same trophic groupings.
- Montenegro M.E., Pugliese N. & Sciuto F. (2004)
Shallow water ostracods near the Mae Khlong river mouth (NW Gulf of Thailand)
pp. 225-234
The study of the ostracod fauna of shallow marine environments strongly influenced by human activity off the Mae Khlong river mouth (NW Gulf of Thailand, north of Phetchaburi) allows the identification of 34 species. belonging to thanatocoenosis and, subordinately to biocoenosis. The relationships between ostracods and water depth and substrate are discussed in order to identify species which are tolerant of the changes in these environmental parameters. Ostracod distributions are also related to salinity, pH and dissolved oxygen. Moreover, using the Shannon Weaver index as a measure of ecosystem health, it has been possible to highlight the deterioration of environmental conditions at the investigated sampling stations and to identify the species which are tolerant of human-induced environmental changes.
- Atnaful B. & Russo A. (2004)
Late Quaternary lacustrine ostracoda of the Ziway-Shala Basin (Ethiopia) as paleoenvironmental indicators
pp. 235-266
Ostracods from a number of Late Quaternary 14C dated outcrop sections and sediment samples from a core in Langano lake have been studied. Simple statistical characterization of valves, counted for each sample, allowed the recognition of different assemblages that have been interpreted as mainly controlled by salinity changes.
Paleoecological evidence confirms salinity fluctuations, caused by climatic changes, which operated on water dilution, during the time interval considered. In addition, the results are in general agreement with previous results of lake-level changes, obtained using diffirent research approaches.
- Bonaduce G., Montenegro M.E. & Pugliese N. (2004)
The brackish water ostracod Cyprideis torosa (Jones) in marine deposits: the case of the Adriatic Sea
pp. 267-271
Cyprideis torosa (Jones), which is one of the most common brackish water species, has been found in the thanatocoenoses sampled at the offshore bottoms of the Adriatic Sea. C. torosa is characterized by the presence of both well-preserved adults and juveniles valves. This evidence should exclude transport processes and, in consequence, should ensure its autochthony. Findings of autochthonous specimens of C. torosa occur in some marine settings of the Saline Gulf (NE Sardinia). There, this species was found in nearshore settings, which are characterized by the presence of fresh water submarine springs, and that may have created favourable conditions such as microhabitats of brackish water. In the Adriatic Sea the situation is quite different. In fact, C. torosa has been found in several offshore sampling, stations that are far away from any fresh water influence and are located in correspondence to deposits with a high content of sand related to late QQQjjkuaternary littoral settings (e.g., nearshore, lagoon) that characterized the central-northern Adriatic region. During the Holocene transgression, these deposits were subsequently preserved and eventually eroded. Moreover, the location of the offshore sampling stations containing C. torosa seems to have a pattern following that of the Holocene shorelines in the northern Adriatic area. Then, C. torosa found within these deposits has to be considered part of an autochtonous late Quaternary brackish water ostracod fauna, that also contains other very shallow marine species tolerating strong fresh water influence, together with rare non-marine ones. Subsequently, some modern deeper water ostracods may have contaminated this fauna as it results from the presence of an apparently mixed brackish/marine ostracod assemblage.
- Bossio A., Gliozzi E. & Tassone L. (2004)
Taxonomy and distribution of the Late Miocene genus Tavanicythere Bossio, 1980 (Ostracoda, Leptocytheridae)
pp. 273-296
The genus Tavanicythere was established in 1980 by Bossio on the basis of several valves recovered in the lower Messinian brackish deposits of the Radicondoli area (Volterra Basin, Tuscany, central Italy). Three species were included in this genus: Tavanicythere lepida Bossio (the type species), Tavanicythere etrusca Bossio and Tavanicythere pulchra Bossio. Since then, many other specimens referable to Tavanicythere have been collected from several Neogene Tuscany basins (Volterra, Valdelsa, Cinigiano-Baccinello), but no specific identifications were carried out and they were generally reported in literature as Tavanicythere sp. In this paper we have revised all the collected material. Up to 15 different new taxa have been recognised, even if only 11 are formally established herein as new species, due, in some cases, to the scarcity of valves: Tavanicythere varieornata nov. sp., Tavanicythere persculpta nov. sp., Tavanicythere posteroalata nov. sp., Tavanicythere sulcata nov. sp., Tavanicythere magna nov. sp., Tavanicythere nodosa nov. sp., Tavanicythere armata nov. sp., Tavanicythere ioachinoi nov. sp., Tavanicyrhere julianii nov. sp., Tavanicythere parva nov. sp. and Tavanicythere irregularis nov. sp. Only few species of Tavanicythere appear to be distributed in different basins, the majority being confined to one basin only. This could be due to particular brackish environmental conditions that triggered basin endemisms. The recovery of new Tavanicythere species lead to enlarge the stratigraphical distribution of this genus, prior limited to the early Messinian, to the time interval Late Tortonian-Messinian. Tavanicythere seems to be widespread only in the Mediterranean basin and, in particular, in Italy (Tuscany). At present, outside of Italy it has been collected only from the late Messinian brackish deposits of the Sorbas basin (SE Spain).
- Horne D.J. & Smith R.J (2004)
First British record of Potamocypris humilis (Sars, 1924), a freshwater ostracod with a disjunct distribution in Europe and southern Africa
pp. 297-306
The freshwater ostmcod Cyprilla humilis Sars, 1924 was first described from the Cape Province of South Africa, together with four other species of Cyprilla Sars, 1924, a genus subsequently considered by other authors to be a subgenus or a junior synonym of Potamocypris Brady, 1870. It was argued that Cyprilla humilis at a single locality on the southern coast of Finland represented a possibly short-lived population, perhaps originating from a single parthenogenetic female, transported from southern Africa by migratory terns which nest in the Finnish archipelago and overwinter in the Cape Province. Subsequent records from the same Finnish locality and another nearby led to the alternative suggestion that it was a long-term resident that had simply been overlooked. Our discovery of a population in a coastal rockpool on an island off the West coast of Scotland provides the first British record and an opportunity for further description and illustration of its morphology and ontogeny. Notable characteristics include: long swimming setae on the antennae; adult carapace with a sharply truncated posterior margin in lateral view and strongly pitted ornament; prominent anterior and posteroventral marginal flanges in the adult left valve; and the occurrence in juvenile carapaces of prominent tubercles which are completely absent in adults. None of these characteristics is considered adequate to merit the retention of Cyprilla as a separate genus or subgenus, however. We consider possible explanations for its disjunct distribution and discuss the evidence for dispersal of ostracods by birds.
Issue 3
Published in December 2004
- Fugagnoli A. & Posenato R. (2004)
Middle Triassic (Anisian) benthic Foraminifera from the Monte Prà della Vacca/Kühwiesenkopf section (Dont Formation, Braies Dolomites, Northern Italy)
pp. 347-360
The recent discovery at Monte Pra’ della Vacca/Kühwiesenkopf (Braies Dolomites) of a significant plant deposit in the lower part of the Dont Formation, a basinal unit consisting of hemipelagic terrigenous-carbonate sediments, prompted an investigation of the benthic forarniniferal assemblage to provide a better chronostratigraphic definition of the deposit. The Anisian benthic foraminifera discovered in this section are widely distributed in the Tethys domain, and have been studied from the Dolomites region by several authors. The foraminiferal assemblage from Monte Pra’ della Vacca/Kühwiesenkopf has never been previously described or illustrated; it consists mainly of Ammodiscidae, Cornuspiridae and Duostominidae which are concentrated in the carbonate banks, while these are lacking in the stratigraphic interval corresponding to the plant deposit. The Pilammina densa, Meandrospira dinarica and Pilamminella semiplana association, typically Pelsonian in most age, characterizes most of the section; towards the topmost layers, the Paulbronnimannia judicariensis-Paulbronnimannella whittakeri association occurs, which is referred to the upper Pelsonian. It is worth noting the occurrence of Paulbronnimannia judicariensis before the appearance of Meandrospira dinarica, and its co-existence with this latter. According to the foraminiferal association and distribution, the plant deposit can be referred to the Pelsonian.
- Venturi F., Nannarone C. & Bilotta M. (2004)
Eoderoceratidae (Mollusca, Ammonoidea) from the “Corniola” of the Central Apennines, related to the Sinemurian-Pliensbachian boundary in the Mediterranean area
pp. 361-382
The Jurassic calcareous successions of the “Corniola” unit in the Umbria-Marche Apennines contain, probably, the oldest known beds referable to the lower Pliensbachian of the entire Mediterranean Tethys. These beds provide important data for the characterization in this area of the global faunal renewal associated with the Sinemurian-Pliensbachian transition. For ammonite assemblages. this change occurred after the disappearance of Echioceratidae (as Paltechioceras), and, in the Apennines, it consists of a set of contemporaneous appearances: Furlites (small, smooth Polymorphitidae, lacking a keel), Catriceras (primitive and morphologically quite variable Tropidoceratinae, more or less lenticular, keeled and spineless), Galaticeras (mass-occurrence), Radstockiceras. This bioevent is accompanied by the spoliation of the Eoderoceratidae, i.e. by the more or less complete loss of the ornamentation, with the transition from bispinate to monospinate or smooth (spoliated) forms. The present paper deals with the Eoderoceratidae found in the rich fossil:fermis bed “Venturi ’78” (Catriceras catriense bioevent) from the Pallareto Quarry (Mount Acuto), which represents a substantial renewal compared to undoubtedly Sinemurian faunas. Due also to this reason, this bed should be considered the first after-Sinemurian record (beginning of “Tetraspidoceras quadrarmatum” Zone) of the Apennines.
All the taxa represented in our collection (67 specimens, including some forms left without generic and/or specific identification) share various morphological and structural (namely sutural) features, and therefore we think that they must be all included in a single new eoderoceratid subfamily that we called Paramicroderoceratinae.
For our specimens we recognized four species, only one of which (Paramicroderoceras cf. bispinatum) is assigned to an already-known genus. The remaining three species are included in two new, here proposed genera: Omoderoceras (which comprises the new species 0. cantianense as well as 0. cf. latinodosum, which is a firm comparable with a taxon previously assigned to Epideroceras) and Paraderoceras (described for the new species P. picenum).
The presence of an inner monospinate phase of development in the new genus Omoderoceras testifies that, during early Pliensbachian times, the spoliation of the Eoderoceratoidea was a complex pattern, including a paedomorphic transition from smooth innermost whorls to monospinate ones (this monospinate character is well established in Caleites, Miltoceras and some yet undescribed Mediterranean taxa). Conversely in the late Sinemurian, this variation was mainly a peramorphosis. simply occurring with the change from bituberculated inner and medium stages to smooth outer whorls (this is, for example. the case of Epideroceras).
The GSSP of the Sinemurian-Pliensbachian boundary proposed for the Wine Haven section (Robin Hood’s Bay, Yorkshire, England) provides a good reference for Boreal and Sub-boreal regions (North-West Europe), but not for the Tethyan ones (Italy, Morocco, Tunisia, Albania, etc.). Here, in fact, the standard biostratigraphic criteria that characterize the beginning of the middle Lias (presence of Apoderoceras, associated in the stratotype with Bifericeras donovani, and/or presence of Tetraspidoceras quadrarmatum) are inapplicable. In these areas, therefore, the Sinemurian-Pliensbachian boundary cannot be identified with precision and, in the best cases, the correlation between Boreal and Tethyan sections for the early Pliensbachian lacks reliability and resolution beyond the Subzone scale. Since the Wine Haven section does not seem to assure with acceptable confidence the expected correlation potential outside the Boreal domain, a stratorype for the Sinemurian-Pliensbachian boundary based on the current knowledge, might have a palaeogeographic value limited merely to that domain, and thus a too restricted practical significance. As a matter of fact, a ratification of the above-mentioned GSSP might formally not allow a safe recognition of the beginning of the Pliensbachian in the entire Tethys.
The difficulties in establishing careful correlations between Boreal and Mediterranean Zones for the early Pliensbachian are probably caused by a number of palaeobiogeographic and/or palaeoecologic factors. This must induce the research towards new and more complete stratigraphic studies, especially in the Tethyan domain, where, except in the Apennines. the record for the first early Pliensbachian Zone is very scarce.
- Elicki O. & Pillola G.L. (2004)
Cambrian microfauna and palaeoecology of the Campo Pisano Formation at Gutturu Pala (Iglesiente, SW Sardinia, Italy)
pp. 383-401
The microfossil content of nodular limestones of the late Early to Middle Cambrian Campo Pisano Formation from the Gutturu Pala section of southwestern Sardinia is described and discussed with respect to palaeoecological conditions. Based on detailed facies investigations, the vertical succession of the sedimentary evolution and fossil distribution is interpreted as an environmental change from shallow-subtidal conditions at the beginning of the Campo Pisano Formation to at least deep-subtidal conditions at its end. Due to the faunal characteristics, an interim shallowing during that process is likely.
A dramatic facies replacement with the onset of the Campo Pisano Formation indicates a strong reorganisation of the environment, explained by tectonic instability of the platform, accompanied by moderate relative sea-level rise and palaeogeographical and maybe climate changes. During most of the time, the persistence of only one palaeoecological assemblage indicates a more or less stable, open marine, deeper subtidal environment for most of the Campo Pisano time.
Among the taxa represented in the highly fossiliferous sediments, trilobites, echinoderms, brachiopods, and poriferids predominate; further elements are chancelloriids, hyolithids, pelagiellids, hyolithelminthids, and bradoriid arthropods. This occurrence in the Campo Pisano Formation is published here for the first time, The following bradoriid and trilobite species are newly introduced: Hipponicharion ichnusum n. sp., Condylopyge antiqua n. sp., and – described in open nomenclature – Clavigellus? n. sp.
- Schlagintweit F., Schmid D.U. & Mancini E.A. (2004)
Trinocladus? americanus n. sp., a new Dasycladale from the Upper Jurassic Smackover Formation of the Gulf Coast, United States of America
pp. 403-407
A new Dasycladale (calcareous green alga) is tentatively described as Trinocladus? americanus n. sp. from the subsurface Upper Jurassic Smackover Formation of Alabarna, United States of America. The generic uncertainties comprise the possibilities of either third order laterals or the presence of fertile ampullae between the first order laterals. The description of the new taxon increases the micropalaeontological inventory of the New World Mesozoic dasycladales.
- Manganelli G., Spadini V. & Cianfanelli S. (2004)
The xenophorid gastropods of the Mediterranean Pliocene: the record of the Siena Basin
pp. 409-451
The systematics of fossil Euro-Mediterranean xenophorids is still relatively unknown, due to the many problems involved in studying them (very conservative shell structure, few available shell characters, the fact that the attached objects modify whorl shape and vary in amount, the rarity of certain species and the difficulty of finding well preserved specimens). Most of the relevant literature dates back to the classic monographs on Tertiary molluscs by M. Hörnes, F. Sacco and M. Cossmann.
Seven species have been reported from the Euro-Mediterranean Pliocene: Xenophora crispa (König, 1825), X. deshayesi (Michelotti, 1847), X. infundibulum (Brocchi, 1814), X. plioitalica Sacco, 1896, X. scaldensis Glibert, 1958, Stellaria plioextensa (Sacco. 1896), and S. testigera (Bronn, 1831). However, all but three (X. crispa, X. infundibulum, and S. testigera) are practically unknown.
This paper is devoted to six species found in the Siena Pliocene Basin, a classic Italian Pliocene area. Five of them (X. crispa, X. infundibulum, X. plioitalica. S. plioextensa, and S. testigera) are redescribed and current knowledge about them summarized; the sixth secies, known from a dozen specimens, is described as new: X. davolii n. sp. In the remarks to the new species, the status and the relationships of some classical Euro-Mediterranean Tertiary xenophorid species. i.e. X. deshayesi (Michelotti, 1847), X. burdigalensis (Grateloup, 1847) and X. grateloupi (D’Orbigny, 1852), are discussed.
A neotype is designated for two species (X. crispa and S. testigera) and a proposal of neotype designation is made for some Miocene species: X. deshayesi, X. burdigalensis, and X. grateloupi.
- Badodi A. & Gnoli M. (2004)
Evidence of a Quaternary vertebrate fauna from fluvial-lacustrine sediments of the River Secchia, Emilian northern Apennine foothills (Italy)
pp. 453-466
Fossil remains of Cervidae, Rhinocerotidae, Bovidae and Mustelidae, recovered in the Secchia riverbed between 1999 and March 2003 are described, The findings are from mid-Pleistocene fluvial-lacustrine sediments belonging to the so-called “Lower Emiliano- Romagnola Alloformation” sharply erosional overlapping deep-sea sediments. The fauna is characterised by: Stephanorhinus etruscus (Falconer), S. hundsheimensis (Falconer), Leptobos sp., Cervus elaphus Beninde, and Martes martes cf. latinorum (Barrett-Hamilton). Cervus perrieri (Croizet & Jobert) is reported for the first time in Italy. Sedimentological data are in contrast with possible fossil reworking, therefore a true coexistence of recovered fauna is not rejected.