ABSTRACTS VOL 109 (2003) N. 3

Upper Carboniferous (Pennsylvanian) conodonts from South Guizhou of China

Wang Zhihao & QI Yuping.

This paper describes in detail che conodont sequence of che Upper Carboniferous (Pennsylvanian) and the upper and lower boundaries in this interval at the Nashui section in Luodian, South Guizhou. The following 23 conodont zones, in descending order, can be recognized: Streptognathodus isolatus, S. wabaunsensis, S. tenuialveus, S. firmus, S. nashuiensis, S. simulator, S. guizhouensis, S. gracilis-S. excelsus, S. cancellosus, S. clavatulus, S. nodocarinatus, Idiognathodus podolskensis, Mesogondolella clarki-Idiognathodus robustus, Diplognathodus orphanus-D. ellesmerensis, ldiognathoides ouachitensis, Streptognathodus expansus, Idiognathoides sulcatus parvus, Neognathodus bassleri-Idiognathodus primulus, N. symmetricus-Idiognathodus primulus, N. symmetricus, Idiognathoides corrugatus-I. pacificus, I. sinuatus, I. sulcatus sulcatus and Declinognathodus noduliferus zones. The first occurrences of Streptognathodus isolatus and Declinognathodus noduliferus afe recognized at the bases of che Permian and the Upper Carboniferous (Pennsylvanian), respectively. The Upper Carboniferous (Pennsylvanian) conodont sequences are discussed and based on these conodont sequences, correlations between Upper Carboniferous (Pennsylvanian) Stages in Chinese and Russian sections, as well as North America are discussed. Additionally, eight new conodont species are also described in this paper.

Carboniferous-Permian stratigraphy and fusulinids of the East Iran.

Gzehelian and Asselian deposits of the Ozbak-kuh Region

Ernst Ja. Leven & Azizolah Taheri

Deposits of the Gzhelian-Asselian Stages were recognized by fusulinid occurrences in the upper part of the Sardar Formation (Zaladu Member) of the Ozbak Kuh region, East Iran. These deposits cannot be referred to the Bage-Vang Formation, which contains Bolorian fusulinids of the early Permian and lies at the base of a trangressive carbonate sequence. The results obtained in the Carboniferous-Permian section of East Iran are similar to those of western and southern Tethys. Everywhere the Asselian and, locally, the Sakmarian deposits are closely related to the Upper Carboniferous ones. After the late Sakmarian.Yakhtashian regression, carbonate platforms were formed from the Bolorian time through the Late Permian. The Zaladu Member contains 10 genera – Rauserites, Kushanella (?), Schellwieina, Anderssonites (?), Praepseudofusulina, Quasitriticites, Ruzhenzevites, Paraschwagerina, Pseudoschwagerina, Sphaeroschawagerina (?), and 37 species and subspecies of fusulinids. New species and subspecies are described: Rauserites infrequentis, R. tabasensis, R. fusoides, R. inobservabilis, R. (?) persicus, Quasitriticites iranicus, Ruzhenzevites zaladuensis zaladuensis, R. zalanduensis brevis, and R. ferganensis curtus.

Upper Olenekian (Spathian) ammonoids from Chios (Lower Triassic, Greece):

taxonomy and stratigraphic positions

DOROTHEE Mertmann & VOLKER Jacobshagen

On the Greek island of Chios, Lower Triassic sections bave delivered rich ammonoid faunas from red limestones of the Hallstatt facies. Here, we present a palaeontological description of Spathian ammonoids, which have been collected during two field campaigns by Italian-German teams (Assereto et al. 1980; Gaetani et al. 1992). The ammonoid associations are composed of Ceratitida and Phylloceratida, each order containing species of the Noritaceae, Hedenstroemiaceae, Xenodiscaceae, Dinaritaceae, Pinacocerataceae, Phyllocerataceae, Ptychitaceae, Ussuritaceae and Megaphyllitaceae. Long ranging genera, e.g. Procarnites and Leiophyllites, are present as well as endemic ones, e.g. Chiotites, which occurs exclusively in the Lower Triassic of Chios. The ammonoid association is indicative of the Prohungarites-Subcolumbites zone sensu Kummel (1973a). The haugi zone, installed as uppermost Olenekian in North America, is not represented by ammonoids on Chios.

Refined ammonoid biochronostratigraphy of the Bagolino section (Lombardian

 Alps, Italy), GSSP candidate for the base of the Ladinian stage

PaOLO Mietto, PIERO Gianolla, STEFANO Manfrin & NEREO Preto

A refined ammonoid biostratigraphy is reported for a critical interrval of the Bagolino section (Giudicarie Area, Northern Iraly), a candidate for the Anisian/Ladinian stage boundary. The Avisianum Subzone has been documented, and its boundary with the Crassus Subzone has been redefined, on the basis of new findings of Reitziites reitzi, Aplococeras aff. smithi, Aplococeras avisianum, Halilucites rusticus, Parasturia sp. and other significant ammonoids. Six potential criteria for the definition of the Anisian/Ladinian boundary can now be considered in this single stratigraphic section, so that the FO of Eoprotrachyceras curionii is no longer the unescapable choice at Bagolino. Despite several drawbacks, including the absence of palynomorphs and daonellid bivalves, the thermal history preventing the recovery of magnetic and isotopic signals, and a lower sedimentation rate with respect to many other sections of the Southern Alps, the Bagolino section is here accepted as stratotype for the Anisian/Ladinian boundary, but further paleontological and sedimentological studies should be considered.

A new lepidosauromorph reptile from the Middle Triassic of the Dolomites

 (Northern Italy)

 Silvio Renesto & Renato Posenato

A new genus and species of diapsid reptile is described. The specimen was collected from the Anisian (Middle Triassic) succession of Monte Prà della Vacca (Kühwiesenkopf) in the Dolomites of Braies (Bolzano/Bozen, Northern Italy). Despite being incomplete, the specimen shows enough characters to allow its placement within Lepidosauriformes, close to the Middle Jurassic genus Marmoretta. The importance of this find lies in the great rarity of lepidosauriforms of Anisian age, an epoch approximating the appearance of the first members of the true Lepidosauria (rhyncocephalians and squamates). The new genus may thus add knowledge to the diversity of early lepidosaurians. Some characters of the skeleton, mainly of the forelimb, suggest a terrestrial, perhaps arboreal life style.

A complete specimen of Mystriosuchus (Reptilia, Phytosauria) from the Norian (Late

 Triassic) of Lombardy (Northern Italy)

Emanuele Gozzi  & Silvio Renesto

A complete and nearly articulated new phytosaur specimen is described in detail. The skeleton, about 4 metres long, has been collected from the uppermost level of the Calcare di Zorzino (Norian, Upper Triassic) in the small quarry of Endenna (Bergamo, Northern Italy). Available characters of the skull allow assignment of this long snouted, uncrested phytosaur to Mystriosuchus planirostris Von Meyer 1863. The postcranial anatomy, detailed here for the first time for this species, suggests a stronger adaptation to aquatic life in Mystriosuchus than in other phytosaurs, and may increase available data to improve our knowledge of the systematic relationships among phytosaurs. The discovery of this nearly complete skeleton in a marine intraplatform basin suggests that a short post-mortem transport of the carcass occurred and thus this phytosaur may have lived whether in a fresh water environment or in a shallow marine habitat, close to emerged lands.

Dinoflagellate cysts and calcareous nannofossils from the Upper Cretaceous

 Saraceno Formation (Calabria, Italy): implications about the history

of the Liguride Complex

STEFANO Torricelli  & MARIA ROSA Amore

Organic-walled dinoflagellate cysts and calcareous nannofossils recovered from the turbidites of the Saraceno Formation outcropping in the type area (north-eastern Calabria, Italy) are presented. They provide new information about the age of the Saraceno Formation, hence a constraint to reconstruct the timing of deformations that affected the Liguride Complex. The distribution of dinoflagellate cysts and calcareous nannofossils in the succession studied is compared with biostratigraphies available for the Upper Cretaceous. Accordingly, the age of the lowermost part of the Fiumara Saraceno section is latest Albian to Turonian, whereas the upper part of the section is dated as late Campanian-?earliest Maastrichtian. A hiatus spanning che Coniacian, che Santonian and most of che Campanian is inferred between these two successions, which are also distinguished by the presence and absence of flint respectively. Consistencies and discrepancies of che present data with biostratigraphical information previously published for che Saraceno Formation, are discussed.

The Castagnone site (Cerrina Valley, Monferrato Hills, NW Italy): early Pleistocene

 sedimentary record and biochronology

CARLO Giraudi, ALBERTO Mottura, BENEDETTO Sala, M. STELLA. Siori & DANIELE Bormioli

Geological researches carried out near che Castagnone hamlet in che Cerrina Valley (Northem Monferrato Hills, Piedmont, NW Italy), have brought to light a post-Messinian succession whose sedimentary record starts with a Lower Complex of pedogenized colluvial materials and with two superimposed Alluvial Units (I and II). The lower one of these units contains a Galerian macrofauna associated with microtine vole teeth (Mimomys savini, Mimomys pusillus, Ungaromys cf. U. nanus, Microtus (Allophaiomys) sp.), while che upper one yields only scarce faunal remains. Most of this sediments were deposited during a normal palaeomagnetic phase. The I Alluvial Unit, due to its biochronological correlation, must be referred to the Jaramillo Subchron, between 1,070,000 and 990,000 years ago. The II Alluvial Unit, being both unconformable with and younger than the first one, might be best referable to the Brunhes Chron. Overall, the bed dipping across the reported succession shows a progressive syn-sedimentary tilting, with accelerated deformation during the I Alluvial Unit deposition. This tectonic stress over the Castagnone area is seemingly related to the uplift of the north-easternmost ridge of che Monferrato Hills and appears to have been nearly exhausted before the II Alluvial Unit deposition.

A new early Pleistocene bird association from Pietrafitta (Perugia, Central Italy)

GILDA Zucchetta, SERGIO Gentili & MARCO Pavia

We here present che preliminary results of the analysis of the fossil bird assemblages found in the lignite deposits of the Pietrafitta Mine (Perugia, Central Italy). A rich vertebrate association, mainly mammals, has been retrieved in Pietrafitta, which is the richest local fauna of the Farneta Faunal Unit (late Villafranchian, early Pleistocene). Avian remains of Podicipedidae, Ardeidae, Phalacrocoracidae, Anatidae, Phasianidae and Rallidae have been identified, for most of which Pietrafitta represents the earliest occurrence in Italy. The Pietrafitta fossil bird association is the first Italian bird assemblage of the Early Pleistocene and seems to be one of the most important ones for the early Pleistocene in Europe, especially because it contains mainly aquatic birds, often rare in many other European deposits.

Brackish marsh benthic microfauna and paleoenvironmental changes during the

 last 6000 years at the coastal plain of Marathon (SE Greece)

MARIA V.Triantaphyllou, KOSMAS Pavlopoulos, THEODORA TsoUrou & MICHAEL. D. Dermitzakis

The present study, based mainly on the analysis of foraminifers and ostracodes, provides evidence of paleoenvironmental changes on the coastal plain of Marathon (E. Greece) during the last 6.000 yrs. Three sedimentary units -lagoonal formations - were recognized and identified as A, B and C. They range in time between before 5500BP-3500BP, 3500BP-2500BP and 2500BP-recent, respectively. The study of the brackish marsh microfauna of the Marathon plain Holocene sediments reveals the presence, during the last 5500 yrs., of three distinct biofacies in the sedimentary units already established. Alternating mesohaline - oligohaline (MO), oligohaline - fresh water (OFW) and mesohaline - oligohaline to oligohaline - fresh water (MO-OFW) biofacies in the framework of the sedimentary units indicate a general trend landward along the plain suggesting a slowing of sea-level rise probably correlated with a relevant tectonic uplift. One prominent feature of this study is the clarification of the ecological preference of the species Trichohya1us aguayoi (Bermudez, 1935), which is dominant in oligohaline conditions under an influence of fresh water input (salinity less than 15 ‰).

BENTHIC FORAMINIFERA RESPONSE TO METHANE RELEASE IN AN ADRIATIC SEA POCKMARK

Giuliana Panieri

The presence of methane-bearing shallow sediments in the Adriatic Sea has been known since the fifties, but little is known about the benthic foraminiferal assemblages associated with them. One seep and two control cores were collected in the Bonaccia field (central Adriatic Sea) at a water depth of 80 m to investigate the possible influence of the release of gas from marine reservoirs on these foraminiferal assemblages. The seep core was drilled inside a pockmark in the vicinity of an active mud-volcano. Two control cores were collected in nearby areas unaffected by presence of methane. Benthic foraminiferal assemblages from the seep core are comparable to those from the seep-free cores and are composed of species common in the central Adriatic Sea. However, foraminiferal density in the seep-core is remarkably lower than in the control ones cores. Besides, calcitic foraminiferal tests from the seep core revealed unusual trends in stable carbon isotope composition. Even though not within the same range, a similar trend was observed throughout the seep core for the δ¹³C values of Gavelinopsis lobatulus, Cassidulina carinata, and Bulimina marinata. In particular, negative carbon isotope values were recorded for Gavelinopsis lobatulus at the top of the core where methane seeps were detected and deep inside the core sediments (50 cm). These findings seem to point to temporal variations in seep activity, proving that the δ¹³C values of foraminiferal tests reflect hydrocarbon release and may hence be used to reconstruct seep activity history.

TABLE 1 - Number of benthic foraminifera from GAB1core samples

TABLE 2 - Foraminiferal percent of the total benthic foraminiferal fauna from GAB1 core samples

TABLE 3 - Number of benthic foraminifera from GAB2 core samples.

TABLE 4 - Foraminiferal percent of the total benthic foraminiferal fauna from GAB2 core samples.

TABLE 5 - Number of benthic foraminifera from GAB3 core samples.

TABLE 6 - Foraminiferal percent of the total benthic foraminiferal fauna from GAB3 core samples.

A pliosaurid tooth from the Argille Varicolori Formation. near Castelvecchio di

 Prignano) (Modena Province, Northern Italy)

CESARE a. Papazzoni 

The first discovery of a Cretaceous pliosaurid tooth in Italy is reported. It comes from the Cenomanian-lower Campanian Argille Varicolori Formation near Castelvecchio di Prignano (Modena Province, northern Italy). Excepting this new specimen, Italy's only reported pliosaurid is a humerus from the Upper Cretaceous of Zavattarello near Pavia. The tooth morphology allows it to be ascribed to Polyptychodon interruptus Owen, 1841, a species only reported thus far from northern-central Europe (England, Germany, and the Czech Republic). This suggests the presence of marine reptile remains in the northern Apennines may have been underestimated.

Records of Metaxytherium medium (Mammalia: Sirenia) from Tononian (Late Miocene) sediments from che Arenaria di Ponsano Formation (Tuscany, Italy) are described. They consist of fragmentary specimens, including several partial cranial elements representing at least three skulls, two humeri, fragments of venebrae and some incomplete ribs. The new Tuscan records confirm che wide diffusion of Metaxytherium in the Mediterranean during the Miocene. This sirenian's occurrence in the Arenaria di Ponsano sediments is in accordance with the shelf environment indicated by other fossils. The low sea bottom was at least partially covered by segrass meadows, the food source of this dugongid.

Eostyloceros cf. pidoplitschkoi Korotkevitsch 1964 (Cervidae, Muntiacinae): new

 element in the Neogene mammal assemblage of Lower Valdarno

(Tuscany, Central Italy)

LAURA Abbazzi  & ROMAN Croitor

An Eostyloceros antler fragment is described. The specimen makes part of the Montopoli (Lower Valdarno, Tuscany) collection preserved in the Geo-Paleontological section of the Natural History Museum of Florence. This site is the type locality of the homonymous Faunal Unit of the Italian Biochronological scheme; it includes the latest Early Villafranchian Mammal Age faunas. The occurrence of an Eostyloceros species among this material however, is in disagreement with the age of the Montopoli local fauna, which has been correlated with the Gauss-Matuyama boundary and thus dated to about 2.6 Ma. The youngest remains of this genus come from sites of eastern Europe Early Pliocene in age (Ruscinian Mammal Age). The possibility that the antler is an external element to the Montopoli assemblage is therefore contemplated.