Bollettino SPI Vol. 42 - Issues 1-2, 3
Issues 1-2
Published in June 2003
- Hammann W. & Serpagli E. (2003)
The algal genera Ischadites Murchison, 1839 and Cyclocrinites Eichwald, 1840 from the Upper Ordovician Portixeddu Formation of SW Sardinia
pp. 1-29
From the siliciclastic Portixeddu Formation, Late Caradoc-Early Ashgill, of Sardinia the genera Ischadites (Receptaculitidae) and Cyclocrinites (Dasycladales) are described. They are represented by Cyclocrinites aff. vanhoeffeni Stolley, 1898 in the lower part and Cyclocrinites sp., Ischadites sp. a and Ischadites sp. b in the higher part of the formation. Cyclocrinites sp. is preserved only as an allomorphic structure at the base of bryozoan colonies. Secondary growth of the thallus of Cyclocrinites happens by addition of a new lateral in the centres of rosettes. As this growth mechanism is different from Receptaculitidae but found in certain Dasycladales, cyclocrinitids are included into the latter. Variation in abundance and spatial distribution of the algae correlate with water depth indicated by energy level, benthic associations and qual- ities of the substrate. In Sardinia Cyclocrinites is confined to siltstone beds deposited below normal wave base. Its association with the Svobodaina Fauna in the lower part and the Nicolella Community in the upper part of the Portixeddu Formation suggests correlation with Benthic Associations 3-4 indicating water depth of 20-60 m. Within this scope the abundance decreases with decreasing depth. Cyclocrinites is absent in intercalated mudstone Beds as well as a very shallow near shore sandstone facies with Calymenella boisseli and Dreyfussina exophthalma. Ischadites has been found only at one locality where it rarely occurs in storm dominated mudstones. The occurrence of the circumequatorial, warm water elements Ischadites and Cyclocrinites supports the concept of southequatorial currents that transported temperate water masses and larvae via Baltica to the North Gondwana margin during Late Caradoc to Middle Ashgill times. It also supports plate tectonical concepts that view SW Sardinia in a marginal position within the outer unstable shelf region of North Gondwana during that time.
Štorch P. & Leone F. (2003)
Occurrence of the late Ordovician (Hirnantian) graptolite Normalograptus ojsuensis (Koren & Mikhaylova, 1980) in south-western Sardinia, Italy
pp. 31-38
Common graptolite rhabdosomes assigned to the late Ordovician zonal index species Normalograptus ojsuensis (Koren & Mikhaylova, 1980) are recorded from the upper part of the Punta Arenas Member of the Rio San Marco Formation (Iglesiente-Sulcis region, south-western Sardinia). They provide biostratigraphical evidence for the previous assumption that at least the upper part of the Punta Arenas Member is Rawtheyan/Hirnantian or early Hirnantian in age. The present graptolite material refers the upper part of the Punta Arenas Member to the early Hirnantian extraordinarius — ojsuensis Biozone. The Hirnantian age of the succeeding Cuccuruneddu Member has already been established by the presence of an Hirnantia Fauna and glacio-marine diamictites.
- Mastandrea A., Perri E., Neri C. & Russo F. (2003)
Conodont biostratigraphy of the Norian-Rhaetian deposits in the Northern Calabria: the Valle Corvino and Grisolia sections
pp. 39-47
The present paper deals with the bio-chronostratigraphy of the Upper Triassic sediments in the Northern Calabria. The study has been carried out through the conodont biostratigraphy of two sections (Valle Corvino and Grisolia, Cosenza, Italy) representing, as a whole, the Triassic basinal successions pertaining to the Verbicaro Unit Auct. The sections yielded three distinct monotypic faunas of Norian and Rhaetian age, represented, in the stratigraphic order, by: a) Epigondolella n. sp. C population Orchard, 1983; it has been found in the lower part of the Valle Corvino section as well as in the upper slope of the adjacent carbonate platform; it allows to refer the upper part of the Lower Unit to Mid-Alaunian; b) Epigondolella slovakensis (Kozur) emend. Budai & Kovacs, 1986; it occurs through large part of the Valle Corvino section, within the Upper Unit, and can be referred to the Late Alaunian-Sevatian; c) Misikella posthernsteini Kozur & Mock; it occurs in the lower part of the Grisolia section and, being preceded by M. hernsteini, marks the base of the Rhaetian Stage.
Therefore, in this sector of Northern Calabria, it has been possible to date accurately the basinal successions and the correlated carbonate platforms. The monotypic nature of the faunas and the presence of E. slovakensis suggest that the studied sediments have been deposited within an intraplatform trough characterized by disoxic to anoxic conditions.
- Brunetti M. & Vecchi G. (2003)
On the finding of Teretia elegantissima (Foresti, 1868) in the Emilia and Tuscany Pliocene
pp. 49-57
The Authors would like make known the discovery in some localities of Emilia, and for the first time in two coeval localities of Tuscany too, of Teretia elegantissima (Foresti, 1868), an exclusive species of Italian Pliocene, recorded only in the past century (Seguenza, 1875, in 1873-77; Bellardi, 1877; Bagatti, 1881). The study point up the filetic importance of the species within a natural group conventionally named “Teretia anceps group”.
- Bianucci G., Landini W. & Varola A. (2003)
New records of Metaxytherium (Mammalia: Sirenia) from the late Miocene of Cisterna quarry (Apulia, southern Italy)
pp. 59-63
New records of Metaxytherium (Mammalia: Sirenia) from Tortonian (late Miocene) sediments of Cisterna quarry, Apulia (southern Italy) are described. They are two fragmentary specimens consisting of a skull roof with one associated rib and one isolated rib. On the basis of this datum and other published and unpublished records, Metaxytherium occurred relatively frequently and with a wide geographical distribution in the Mediterranean during the Miocene. In particular, high frequency and wide distribution have been observed in the late Miocene for the species M. medium, the only recorded in the Mediterranean during this time interval.
- Di Stefano G. & Di Canzio E. (2003)
Pleistocene Artiodactyls from Vieste (Gargano, Italy)
pp. 65-74
Some bone remains in a fairly good state of preservation have been collected during a field work in the area of Vieste (Gargano promontory, Southern Italy). The remains have been found in a wide fissure inside the calcareous rocks of an old quarry. The studied bones can be attributed to four Artiodactyls species representing a local fauna referable to the late Middle Pleistocene. More particularly the presence of Dama dama tiberina and of an advanced form of Cervus elaphus allow to refer the remains from Vieste to the Vitinia Faunal Unit. The age showed by these remains is also important because they represent the first occurrence of a faunal association referable to the middle Aurelian in the Adriatic side of central-southern Italy.
- Martinetto E. (2003)
Leaves of terrestrial plants from the Pliocene shallow marine and transitional deposits of Asti (Piedmont, NW Italy)
pp. 75-111
This paper provides an updated taxonomic synthesis on the leaf assemblages from the shallow marine and transitional deposits of the surroundings of Asti, whose deposition took place within latest Early Pliocene and/or early Middle Pliocene (ca. 3.8-3.1 Ma). The 1960s and 1990s collections from the basal part of the Arboschio quarry, stored at the Museo di Geologia e Paleontologia of the Turin University, have been thoroughly revised. In addition the fossil leaf specimens recently collected from Asti-Cascina Risso, Baldichieri-Fornace, Baldichieri-North, Castagnole Monferrato, Cerro Tanaro and Valmanera have been studied. Furthermore, a taxonomic revision of lost material from Castello d’Annone, Ferrere, San Damiano and Pralormo has been attempted on the basis of unpublished drawings by Paolo Peola (ca. 1890). The composition of the majority of assemblages studied is rather homogeneous, so that reference is made to a collective “Asti” palaeoflora, dominated by deciduous trees which formed at least two types of plant communities: azonal riparian forests and zonal mesophytic forests. The abundance of riparian elements testifies that the leaf remains were transported by rivers to the shallow-marine bottoms, probably in occasion of strong floods. The “Asti” palaeoflora provides a good leaf signature for the “Stura Floristic Complex’, previously defined on the basis of fruit and seed assemblages. Such complex represents a phase when the western margin of the Po Basin was covered by high-diversty forests of East Asian affinity, with dominant summergreen trees, indicating warm-temperate and humid conditions (mean annual temperature around 13-14 °C).
- Bona F. & Cattaneo C. (2003)
Unusual tracks of predation on Ursus spelaeus
pp. 117-121
The present study led to the identification of a failed attempt at predation dating about 39,000 years ago. This attack left healed signs of trauma on the cranial vault. The object of this study is a young cave bear (Ursus spelaeus) found at the Caverna Generosa (Lo Co 2694), located on Italian side of Monte Generoso (Como). The study entailed CAT scans and the macroscopic study of the bones which showed how the trauma suffered by the young bear was not lethal: in fact the animal died probably 3 to 12 months after this attack. The morphology of the partially healed lesion has led the authors to the following reconstruction: an attack from behind and above, using probably the two right canines (upper and lower). The list of possible predators includes: Panthera leo spelaea, Crocuta crocuta spelaea, Canis lupus and the cave bears themselves. Given the characteristics of Crocuta crocuta spelaea and Canis lupus, the most likely predators are bear and lion.
- Bonfiglio L., Galeani D., Mangano G., Marra C.A. & Insacco G. (2003)
Elephas falconeri (Busk, 1867) and Leithia melitensis (Adams, 1863) from a karst fissure of the Hyblean Plateau (South-eastern Sicily)
pp. 123-128
A new karst fissure deposit containing vertebrate fossil remains has been recently found during building works at Contrada Annunziata, in the Ragusa carbonatic platform. The excavations have brought to light a cavity, filled with red residual soil sediments containing several skeletal parts of the pigmy elephant Elephas falconeri (Busk, 1867) and giant dormouse Leithia melitensis (Adams, 1863), associated with some limbs bones of birds and scarce carapace fragments of tortoise. Some E. falconeri remains have been found in anatomical connection. L. melitensis remains were particularly accumulated into two points. Taphonomic features suggest that the fissure acted as a morphological trap, where remains accumulated after animal death. Micromammal remains could reach the cave as disgorged piles by birds of prey. The new faunal assemblage of Contrada Annunziata belongs to the Elephas falconeri Faunal Complex, early Middle Pleistocene in age, characterized by a poorly diversified faunas with marked endemic features, such as the large mammals dwarfism (E. falconeri) and the small mammals giantism (L. melitensis) The new finding of Contrada Annunziata represents a new contribution to the knowledge of the Quaternary vertebrate populations of Sicily.
- Di Canzio E., Bedetti C., Petronio C. & Sardella R. (2003)
Middle Pleistocene vertebrate fauna from Cretone (Sabina, Latium)
pp. 129-132
A fossil vertebrates assemblage has been discovered near the Cretone spa (Sabina, Latium). The fauna can be referred to the late Middle Pleistocene (Torre in Pietra F.U., Aurelian Mammal Age). Several taxa of small and large mammals and the avifauna testify temperate-cold climatic conditions and a woody environment with several open spaces.
- Di Geronimo I., Di Geronimo R., Rosso A., Girone A. & La Perna R. (2003)
Autochthonous and allochthonous assemblages from Lower Pleistocene sediments (Palione river, Sicily)
pp. 133-138
Fossil assemblages from lower Pleistocene sediments cropping out along the Palione river (Grammichele, SE Sicily) and belonging to the basal part of the Poggio Spica Unit have been studied. Sediments, 12.5 m thick, are mainly pelitic and contain some fossiliferous layers in their upper part, where a coarse organogenic level, 30 cm thick, is also present. Marls contain autochthonous fossil assemblages, mainly consisting of molluscs, bryozoans and fish otoliths, and indicating a shelf-margin environment grading into the bathyal zone, with an inferred depth of 100-200 m. The coarse organogenic bed is mostly formed by calcareous algae, for which an allochthonous origin from mid-shelf (40-80 m) current swept bottoms is inferred. This algal bed is explained as caused by a gravitative mass deposition.
- Frigo Sorbini M., Landini W. & Piccoli G. (2003)
Bolca: thirty years (1968-1998) of activity and research
pp. 139-143
The over 250 species of 140 genera, 90 families and 19 orders recognised in Bolca represent the worldwide most important fossil fish association of reef environment. The modern knowledge on the Bolca fauna preserved in the City Museum of Natural History in Verona and in many other museums scattered all over the world, is the result of a research program started thirty five years ago by Jacques Blot and Lorenzo Sorbini. Two lines of research developed along with this activity: one of systematic-philogenetic type, the other with paleoecologic interest. Since 1968 systematic studies have been carried out for the redefinition of historic taxa and for the definition of new taxa. In the 60s, 70s and 80s Cav. Massimiliano Cerato, heir of a family of quarrymen who escavated in Bolca for more than 200 years, according to a particular State agreement, carried out the excavation under the control of the Verona Museum. The Bolca deposit is the fossiliferous site with the more ancient historic documentation. Since 1500, when the area belonged to the Republic of Venice, until now, not less than 250 million people in the five continents became acquainted with Bolca fossil fishes.
- Marra A.C. (2003)
Ursus arctos from selected Pleistocene sites of Eastern Sicily
pp. 145-150
In this paper, bear remains coming from three Pleistocene sites of Sicily are studied. In two sites (Acquedolci, near Messina; Contrada Cimilla, near Ragusa) the remains are contained in an assemblage of the Elephas mnaidriensis Faunal Complex(late Middle Pleistocene-late Pleistocene), while in Contrada Pianeti (near Ragusa) the assemblage is typical of the “Grotta S. Teodoro-Pianetti” Faunal Complex (late Pleistocene). Morphological and biometrical data are according to those known for Pleistocene and modern Ursus arctos. The bears of Sicily are very similar to mainland ones and seem to have not endemic features due to insular conditions.
- Palombo M.R. & Curiel V. (2003)
Tooth microwear analysis of Mammuthus (Archidiskodon) meridionalis gromovi (Alexeeva & Garutt, 1965) from Montopoli (Lower Valdarno, Tuscany, Italy): a methodological approach
pp. 151-155
The alimentary habits of large mammals can be deduced from the microwear tracks on tooth enamel examined under the Scanning Electronic Microscope. The data obtained from a preliminary analysis of the last upper molars of a Mammuthus meridionalis gromovi (Alexeeva & Garutt, 1965) specimen from Montopoli (lower Valdarno, Tuscany; Montopoli faunal unit, Middle Villafranchian Mammal Age) are consistent with the hypothesis of a predominantly browser type of diet. During the deposition of the fossiliferous level, the paleoenvironment at Montopoli was likely to have been quite open, as shown by paleovegetation data; browsing in elephants may be explained by the increase in browse eaten during the dry period, when grass tended to wither, as reported for most extant savanna elephants.
- Palombo M.R., Melis R., Meloni S. & Tuveri C. (2003)
A new Cervid in the Pleistocene of Sardinia: preliminary report
pp. 157-162
In the Su Fossu de Cannas Cave (Sadali, central-eastern Sardinia), cut into the Mesozoic limestone in the Barbagia of Seulo, various cervid remains have recently been discovered whose dimensions exceed the range of variability calculated for the endemic species “Megaceroides” cazioti (Depéret, 1897), and are comparable to those of the continental red deer. The specimens analysed thus far, however, show close morphological affinities with endemic Sardinian megalocerines, from which in any case the Sadali cervid differs in its proportionally smaller teeth and limb proportions, as well as in some morphological features which, if confirmed by further data, might suggest its attribution to a new taxon, congeneric with the endemic species “Megaceroides” cazioti, of which it might be the ancestor.
- Pavia M. & Bedetti C. (2003)
The late Pleistocene fossil avian remains from Grotta dei Fiori, Carbonia (SW Sardinia, Italy)
pp. 163-169
The results of the analysis of the fossil bird association from a clay and sandy-clay succession filling a karst cavity, known as Grotta dei Fiori, close to the town of Carbonia, SW Sardinia, are presented. A rich vertebrate association was sampled including mostly micromammal, scarce macromammal and bird remains. The micromammals allow to refer the whole association to the Late Pleistocene. The analysis of the fossil bird remains revealed the presence of the following taxa: Ciconia nigra, Gypaetus barbatus, Aquila sp., Columba livia, Turdus viscivorus, Pyrrhocorax pyrrhocorax, Pyrrhocorax graculus, Corvus corone/frugilegus, Corvus corax, Emberiza cirlus/schoeniclus. The bird assemblage contains no endemic taxa, on the contrary of the mammal assemblage, which is wholly formed by species endemic to Sardinia and Corsica. Particular interest is shown by the remains of Ciconia nigra, rarely reported as fossil; this species is quite common in the Grotta dei Fiori assemblage, even with unable-to-fly individuals, testifying its nesting status close to the cave. The fractures and conservation of the micromammal remains allow to hypothize that their accumulation was partially due to the hunting activity of a Strigiformes, even if no fossil remains have been found.
- Sanfilippo R. (2003)
Climatic response in the genus Placostegus Philippi, 1844 from Plio-Pleistocene to Recent Mediterranean, with description of a new species (Polychaeta, Serpulidae)
pp. 171-178
The serpulid genus Placostegus Philippi, 1844 is represented in the Recent Mediterranean by two species: P. tridentatus (Fabricius, 1779), typical of deep circalittoral and bathyal bottoms, and P. crystallinus sensu Zibrowius, 1968 at shallower depths. P. tridentatus is well known from Arctic, Northern Atlantic and Mediterranean waters.
The tube of P. tridentatus is re-described using material from Icelandic waters, the Western and Central Mediterranean, as well as from Plio- Pleistocene sediments of Southern Italy.
An “Atlantic” and a “Mediterranean” morphotype of P. tridentatus are distinguished based on differences in size and morphological characters of the tubes. Some tubes from the Plio-Pleistocene are described as a new species, Placostegus zibrowii.
Stratigraphical, geographical and ecological distribution of these taxa are discussed.
- Sciuto F. (2003)
Preliminary data on Pliocene ostracods from Capo Milazzo (NE Sicily)
pp. 179-184
Ostracod benthic assemblages from deep-water Upper Pliocene sediments cropping out at Cala S. Antonino (Capo Milazzo, NE Sicily) have been studied. Layers, consisting of silts and sands, locally about 13 metres thick, fill previous depressions. They overlie Tortonian conglomerates and are overlaid by Tyrrhenian shallow water deposits topped by tuffs.
Seven samples delivered 43 taxa, 34 of which determined at specific level. Ostracods are relatively abundant (51-113 specimens per sample) although assemblages are poorly diversified, above all in the basal samples. Assemblages mainly consist of a group of five common and abundant species i.e. Bythocypris bosquetiana (Brady), B. obtusata (Sars), Bairdoppilata conformis (Terquem), B. profunda Aiello, Barra & Bonaduce and Agrenocythere pliocenica (Seguenza). Other five species (Costa tricostata (Reuss), C. tricostata pliocenica Ruggieri, Henryhowella sarsi profunda Bonaduce, Barra & Aiello, Acanthocythereis histrix (Reuss) and Quasibuntonia seguenziana (Ruggieri) are less frequent and abundant.
Assemblages are dominated by species whose distribution is restricted to bathyal environments together with species, which are widely distributed. Among the most abundant species in fact the still living Bythocypris obtusata, is known in the Atlantic-Mediterranean region from 595 to 2700 metres whereas Quasibuntonia radiatopora, seemingly extinct in the Mediterranean, has been recorded from 975 to 2780 metres in the Atlantic. Also Henryhowella sarsi profunda seems to have a similar distribution together with the extinct Bairdoppilata profunda and Costa tricostata pliocenica, both species exclusively found in typically bathyal assemblages from the “Trubi” and the grey-bluish clays. Finally it is worth to note the constant presence of Agrenocythere pliocenica, the only ostracod considered as strictly psicrospheric, thus indicating oceanic hydrological conditions. Other species show wider distributions also thriving in shallower waters as Cytherella vulgatella, which colonises also infralittoral bottoms; Bairdoppilata conformis, Pseudocythere caudata and Cytheropteron alatum, also living in all the Circalittoral zone; and Bythocypris bosquetiana and Monoceratina mediterranea, whose distribution extends up to the shelf-break. Species exclusively living in shelf environments are absent or extremely rare.
The scant diversification of species points to a deep-water palaeoenvironment as well as the structure of the assemblages, characterised by the dominance of a few number of species, which appear to be typical of bathyal environments, usually relatively stable although difficult to colonise. All considering, it has been possible to infer a deep palaeobiotope located at a depth seemingly exceeding 600 metres, which agrees with evaluations made using foraminifers.
- Sorbini C. & Landini W. (2003)
A new fishfauna in the Plio-Pleistocene of Monte Singa (Calabria, southern Italy)
pp. 185-189
A new fossil fishfauna (both ichthyoliths and otoliths) is reported from the Plio-Pleistocene sedimentary section of Monte Singa (Calabria, southern Italy). After the correlation of its sapropelitic layers with astronomical cycles, this section has been carefully studied under many different aspects but no fossil fishes had been found in its layers before this find. The fauna consists in 41 taxa, 21 genera, 14 families and 8 orders of Teleostei.
- Testa M. & Andri E. (2003)
Preliminary note on the Upper Miocene Radiolarian assemblage of Cappella Montei (Alessandria)
pp. 191-195
We carried out a preliminary quantitative and qualitative study on the radiolarian fauna of the spongolitic levels of Cappella Montei. The radiolarian assemblage, formed by 60 taxa, proves, in our opinion, that these levels settled in a neritic environment.
- Violanti D. & Gallo L.M. (2003)
New finding of Hastigerinella digitata (Rhumbler) in Messinian outcrops of Piedmont
pp. 197-200
Hastigerinella digitata (Rhumbler), a planktonic foraminifer previously recovered in pre-Pleistocene sediments only in two Messinian outcrops of Piedmont (Northwestern Italy) is preserved also in laminated clayey marls recently exposed in the surroundings of Nizza Monferrato (near Asti, Piedmont). Microfaunas are dominated by planktonic foraminilers and are referable to the lower Messinian, Globorotalia conomiozea biozone. A correlation with the well known Messinian Albese sections is proposed. Moreover, it is here given the first documentation of pelagic pre-evaporitic Messinian in the Asti area.
Issue 3
Published in December 2003
- Tongiorgi M., Bruton D.I. & Di Milia A. (2003)
Taxonomic composition and palaeobiogeographic significance of the acritarch assemblages from the Tremadoc-Arenig (Hunneberg, Billingen, and lower Volkhov Stages) of the Oslo Region
pp. 205-224
Fifty two taxa of acritarchs have been identified from 25 samples of the Tremadoc-Arenig Toyen Shale Formation (Hunneberg-Volkhov) of the Oslo Region, Norway. Preservation is generally poor but most taxa can be identified to the species level. Samples from the Hunneberg Stage contain a mixed cold-water (elements of the messaoudensis–trifidum assemblage) and warm-water (Aryballomorpha-Athabascaella-Lua assemblage) microflora. Samples from the Billingen – lower Volkhov Stages contain species recorded from the Yangtze Platform (South China), which is considered to be part of the cold-water realm (or “Mediterranean Province”) located at high southern latitudes around the margin of Gondwana. However, the Oslo samples lack the typical cold- to cool temperate-water indicatory from Perigondwana, such as Arbusculidium, Aureotesta, Coryphidium, Striatotheca and Vavrdovella. This is compatible with a mid-latitude position of Baltica during the Arenig and with a pattern of ocean currents causing a warmer climate than in China. On the contrary, the late Volkhov-early Kunda Baltic microflora belongs neither to the cold water Perigondwana realm nor to a less well-defined warm-water realm. Evolution in the composition of phytoplankton from an early Arenig “Mediterranean microflora” to a late Arenig “Baltic microflora” occurs in both South China and Baltica. This implies a reciprocal exchange within a mid-latitude realm controlled more by the pattern of subtropical oceanic gyres rather than latitudinal position alone. A similar evolution of acritarch assemblages is also noted over the East European Platform in Russia and Poland.
- Pittau P., Cotza F. & Del Rio M. (2003)
Early Silurian siliceous sponge spicule assemblages from the Sardinia Hercynian Chain (Italy)
pp. 225-239
Moderately well preserved, disarticulated sponge spicules occur in the Llandovery Demirastrites convolutus –Streptograptus crispus zonal succession of south-eastern Sardinia, Italy. The spicules-bearing strata are believed to have been deposited in a distal platform environment, characterized by limited water circulation and anoxic – dysoxic bottom conditions, which is characterized by epipelagic communities of graptolites, chitinozoans and radiolarians. Assemblages recovered from four stratigmphic horizons include fairly diverse siliceous sponge spicules without co-occurrence of sponge body fossils. Representatives of demosponges and hexactinellids have been identified and four distinctive new form taxa, Nabaviella? sp.A, Nabaviella? sp.B, Nabaviella? sp.C and Thoracospongia ichnussiella have been described. These are the first Early Silurian spicule assemblages described from a northern Gondwanan terraine and this is the first recording of specialized propeller-like spicules and pulvinusactines in sediments younger than Cambrian. Given that siliceous sponge spicule assemblages are not frequently discovered in the Lower Paleozoic, these new data add to the understanding of sponge taxonomy, biostratigraphy and evolution. The occurrence of diverse siliceous sponge spicules in oxygen-poor bottom environment, where black shale is deposited, suggests that the sponges were likely transported after death by water currents, or that they lived attached to floating organisms.
- Braga G. & Bahr S.A. (2003)
Bryozoa from the Oligocene succession of Jabal Hafit, Al Ain, United Arab Emirates and Arabian Peninsula
pp. 241-265
The stratigraphy of the Paleogene sequences off Jabal Hafit (Al Ain region, U.A.E. – Arabian Peninsula) is described and analyzed in detail. The Asmari Formation (Oligocene), mostly consisting of shallow water fossiliferous limestones, can be divided in three members. The lower part with maroon brown silty marls (Zakher Mb.) early-middle Oligocene, while the upper (Mutaredh and Muwaiji Mbs.) mainly of algal bioclastic limestones, is entirely of middle Oligocene age. In nearly the whole sequences, fragments of nummulitids, pelecypods, gastropods, echinoids and bryozoans are common. This paper deals particularly with the bryozoans. which are not frequent but very interesting. Fiftyfour species (15 Cyclostomatida and 39 Cheilostomatida), have been recognized; some left in open nomenclature, four being new species: Steginoporella arabica, Adeonellopsis omanensis, Beisselina robusta and Batopora stellata.
The Indo-Pacific character of this bryozoan fauna is emphasized, especially regarding the Tethyan distribution of its content, and the interruption of the supposed eastward bryozoan migration in the Lower Miocene due to the Arabian plate motion. The paleoecology of area, typical of shallow marine water and with warm-temperate or subtropical temperatures, is inferred also in the basis of zoarial form.
- Sciuto F., Rosso A. & Torrisi S. (2003)
Pliocene ostracod assemblages from Centuripe (Sicily): palaeoenvironmental inferences
pp. 267-280
Ostracod assemblages from a 327 metres thick Pliocene terrigenous succession cropping out near Centuripe (Sicily) in a complex geological context, have been studied.
Palaeoenvironmental reconstruction was performed integrating different approaches such as the autoecological meaning of single species with the analysis of specimen abundance, species richness, population structure and taphonomic features, all joined with the grouping of ostracod species within zone distribution stocks. This study allowed tracing the evolution of the depositional basin.
A deep although proximal environment with a palaeobathymetry not shallower than about 300 metres and not deeper than 500 metres has been hypothesised for the basal layers containing species living in bathyal environments, but lacking in the psycrosphaeric ones. Abundant specimens belonging to infra-circalittoral or even exclusively infralittoral species, have been interpreted as displaced from shallower bottoms and added to the authocthonous assemblages. A shallowing has been postulated for the middle part of the section owing to the presence of species having circalittoral-to-bathyal distributions joined with the disappearance of exclusively deep-water species. Finally, the upper part seemingly deposited in circalittoral palaeoenvironments and the top-most part, near the infra-circalittoral boundary as infra-circalittoral species, characterised by shallower depth ranges progressively appear. Allocthonous, exclusively infralittoral inputs are obvious also in this part of the section.
The extent of displacements, all along the section, points to a marginal location of the sedimentary environment, adjacent to a steep palaeobasin border and seemingly triggered off by sintectonic activity.
- Stefanelli S. (2003)
Benthic foraminiferal assemblages as tools for paleoenvironmental reconstruction of the early-middle Pleistocene Montalbano Jonico composite section
pp. 281-299
Quantitative analyses on benthic foraminifera were carried out on the early – middle Pleistocene Montalbano Jonico composite section. Statistical analyses (Hierarchical Cluster Analysis and Principal Component Analysis) were performed to better understand the distributional patterns of the assemblages. Hierarchical Cluster Analysis indicates that a difference between assemblages and benthic foraminiferal distribution exists. The difference and the distribution are related to depth and oxygen content variations, respectively. Results of the PCA – analysis reveals that the greatest correlation with water depth is accounted for by the first axis, while the third and the fifth axes are closely related to oxygen content. In particular, the fifth axis allows the identification of three severe reductions in oxygen content during the periods of sapropel deposition. The Montalbano Ionico composite section deposited during a period of marine regression, registered depth-changes of 500 – 30 m, and was characterized by several shallowing-deepening cycles. The inferred sedimentary cyclicity is believed related to tectono-eustatic forcing in the early Pleistocene and to eustatically-controlled cyclicity in the middle Pleistocene.
- Napoleone G., Albianelli A., Azzaroli A. & Mazzini M. (2003)
Dating the late Villafranchian (Pliocene) vertebrate collections of the Upper Valdarno (Tuscany, Italy) by the magnetochronologic framework of the basin fìll
pp. 301-313
The Upper Valdarno fossil vertebrates in the collections of the Natural History Museum of Firenze include faunas of the
Villafranchian events, but more than 70% of their specimens are catalogued without precise stratigraphic position, and most of them from the old collections. Magnetostratigraphy has dated the earlier two successions of the basin fill, from the late Gauss chron throughout the Olduvai, in
the interval from 3.3 Ma to about 1. 75 Ma, and the fossil faunas there collected can be placed in a chronological asset with time resolutions up to few ky. A relevant part of collections labelled in the Museum inventory with ages of Pleistocene or early Pleistocene is now dated in the last 200 ky of the Pliocene, and shortly after the P/P boundary, which has been fìxed in the stratotype at 1.8 Ma. The new accuracies range from ± 50 ky
for the ones of lesser grade to ± 30 ky for most of the old collections when their position is reconstructed from the catalogue information to lie in one of the lithostratigraphic units which are now well dated. Dates better than this are provided for the best repositioned ones, as Nesti’s Rhinoceros of 1811 dated 1.83 ± 0.01 Ma, and Azzaroli’s Elephant of 1953 at 1.850 ± 0.015 Ma, while the new finds reported with 1 m accuracy in the Faella magnetostratigraphic type section are dated with ± 2 ky.
- Argenti P. & Sardella R. (2003)
Early Pleistocene large mammals from Villa Spinola (Perugia, Central Italy)
pp. 315-321
At the end of the 19th century, in the surroundings of Villa Spinola (Perugia), fossil mammal remains including proboscideans. rhinos, equids. suids, bovids and a panther were discovered. Unfortunately, most of these fossil bones were lost. The present work focuses on the still available fossil bones of Panthera gombaszoegensis and Mammuthus meridionalis (advanced form), stored at Perugia in the Cicioni and Bellucci Collections. Such analysis enables to point out considerations on the faunal assemblage biochronology and on the stratigraphy of the deposit, not visible anymore. The fauna can be referred to the Late Villafranchian (Early Pleistocene). Consideration on the fossilization suggest that the fossil bones come from a paleosoil that has never been recognised below.
- Venturi F. & Nannarone C. (2003)
Oxydiscoceras, a new name for the genus Oxydiscus Venturi & Nannarone, 2002 (Ammonoidea, Arietitoidea), preoccupied by Oxydiscus Koken, 1889 (Gastropoda, Bellerophontidae)
p. 323