ABSTRACTS VOL 108 (2002) N. 3

Marmaronia angiolinii,

new genus and new species of Bakevelliidae (Pterioida, Bivalvia)

from the Middle Permian of Chios (Greece)

    Cristiano Larghi

  Abstract.  The Guadalupian (Middle Permian) “Gymnocodiacean Limestones” cropping out in the north-eastern part of the Greek island of Chios (eastern Aegean Sea) are amongst the most fossiliferous in the western Tethys. They contain rich assemblages of corals, brachiopods, molluscs, calcareous algae, foraminifers and ostracods. Scant attention was given till now to mollusc faunas compared with brachiopods and foraminifers. In the present paper the new genus Marmaronia, with type-species M. angiolinii n. sp., is established to distinguish some bivalves of the Bakevelliidae King, 1850, from the middle Guadalupian successions of the Marmaro locality in Chios Island. M. angiolinii n. gen. n. sp. is strongly inequivalve, with valves differing in convexity, umbo development and ornamentation. The left valve shows a radial furrow running from the anterior part of the umbonal region anteroventrally and is ornamented by strong radial costae; the right valve is ornamented by concentric sculpture and by thin rugae in the first growth stages of the posterior part of the shell. Both valves have a wide posterior wing. Two hypotheses concerning the epi- or endobyssate adaptation of Marmaronia are also discussed briefly in the present paper.

THERMAL HISTORY OF THE CARNIC ALPS (NE ITALY – S. AUSTRIA) USING CAI ANALYSIS

  MONICA PONDRELLI

  Abstract. Thermal patterns of an area which underwent a polyphase deformation history such as the Carnic Alps were analyzed using the Colour Alteration Index (CAI) of conodonts in order to constrain some aspects of the metamorphic history of this part of the Southern Alps. Hercynian and alpine tectonothermal events were distinguished using CAI analysis.  The Hercynian event developed temperatures up to low metamorphic conditions. Alpine tectonogenesis did not produce thermal levels in excess of the diagenetic zone. Moreover, CAI patterns allow recognition and evaluation of a hydrothermal metamorphic overprint of Permo-Triassic or Oligocene age that was superimposed on the pre-existing regional metamorphic zonation.

The Anisian macroflora from the Northern Dolomites (Kühwiesenkopf / Monte Prà della Vacca, Braies): a first report  

Carmen Broglio Loriga, Anna Fugagnoli, Johanna van Konijnenburg - van Cittert, Evelyn Kustatscher, Renato Posenato, Michael Wachtler  

Abstract. The knowledge of Triassic macroflora from the Dolomites mostly concerns the Ladinian, while literature data on Anisian plants are scarce. This gap is filled by the discovery, reported here, of a rich plant deposit from Kühwiesenkopf / Monte Prà della Vacca (Prags/Braies Dolomites). The fossils occur in a horizon, about 1 m thick, from the lower part of the Dont Formation, a basinal unit mostly constituted by hemipelagic, terrigenous-carbonatic sediments of Pelsonian – Illyrian age. The stratigrafic interval with the plant horizon is Pelsonian in age. A preliminary systematic analysis of the numerous and well preserved specimens has allowed the identification of at least 17 genera. The taxa belong primarily to the Pteridophyta (Anomopteris, Neuropteridium, Cladophlebis, Crematopteris, ?Marattiopsis), subordinately to the Cycadophyta (Bjuvia, Taeniopteris, Dioonitocarpidium, Pterophyllum / Nilssonia). Coniferophyta are represented by Voltzia, ?Voltzia and Albertia; the latter genus is recorded herein for the first time in the Middle Triassic of the Dolomites. Besides, two Lycophyta genera (?Isoetites, Lycophyta new taxon), three Pteridospermae genera (?Sagenopteris, Scytophyllum and Peltaspermum), and one Sphenophyta genus (Equisetites) have also been recognized.

MIDDLE TRIASSIC FORAMINIFERA FROM THE SECEDA CORE (DOLOMITES, NORTHERN ITALY)

  FLORIAN MAURER & ROBERTO RETTORI 

Abstract. The assemblage of foraminifera in turbidite beds in Middle Triassic basinal deposits straddling the Anisian/Ladinian boundary interval was studied in 224 thin sections. The fauna consists mainly of shallow-water inhabitants, associated with calcareous hyaline foraminifera (Lagenina) of open marine environment. Due to a well established  biostratigraphy in the studied interval, the first and last appearance of some shallow water, benthic foraminifera can be assigned to the Mid Triassic ammonoid stratigraphy. The species Meandrospira dinarica Kochansky-Devidè & Pantic and Arenovidalina chialingchiagensis Ho are limited to the Reitzi ammonoid zone. The species Variostoma alta Kristan and Hoyenella gr. sinensis both do not superate the Curionii zone in age in the studied succession.  The biostratigraphic most important event occurs at the base of the Gredleri zone,  with the appearance of the family Involutinidae Bütschli, represented by the genera Lamelliconus and Aulotortus. The faunal composition is similar to those of neighbouring paleoprovinces, but generally a lower faunistical diversification compared to foraminiferal assemblages in the Anisian or Carnian is observed.

CAELATICHTHYS GEN. N.: A NEW PALAEONISCIFORM FROM THE MIDDLE TRIASSIC OF NORTHERN ITALY AND CANTON TICINO (SWITZERLAND)

  CRISTINA LOMBARDO

  Abstract. A new genus of “palaeonisciformes”, Caelatichthys gen. n., is described on the basis of a well preserved material from the Kalkschieferzone (Meride Limestone) of  Ca’ del Frate (Viggiù, Varese) and Meride (Canton Ticino, Switzerland). This small sized fish, with elongate-fusiform body, is characterized by a dermosphenotic in contact with the ventral margin  of the dermopterotic, the absence of contact of dermopterotic+dermosphenotic and the nasal bone, the lack of supraorbital bones, the presence of 4-5 infraorbital elements and small premaxilla meeting at the mid-line. Two species were recognized within this genus: C. nitens gen. n., sp. n. and C. meridensis gen. n. sp. n., each exclusive of a single locality. The two species differ in the development of dermal bone ornamentation, in specimens of the same size, and mainly in the pattern of the fulcra of the anal fin. This character cannot be ascribed to sexual dimorphism, as the two fishes showing the two kinds of anal fin were never found together in the same assemblage. The existence of two species of this new genus confirms the great variability of the faunal composition of the different fossiliferous levels of the Kalkschieferzone, with eight species described formally and other whose study is in progress. The good state of preservation of several specimens from Ca’ del Frate also made it possible to reconstruct the growth stages of C: nitens n. gen. n. sp.

LATE TRIASSIC (LATE NORIAN-RHAETIAN) RADIOLARIANS FROM THE ANTALYA NAPPES, CENTRAL TAURIDES, SOUTHERN TURKEY

  UGUR KAGAN TEKIN

  Abstract. The Hocaköy section measured from the Alakirçay Nappe (middle nappe) of the Antalya Nappes contain rich radiolarian fauna ranging from late Norian (Late Triassic) to middle-late Cenomanian (mid Cretaceous). At the basal part of the section, the Late Triassic (late Norian-Rhaetian) Gökdere Formation is characterized by gray to beige cherty limestone at the base and pinkish red chert- gray to beige limestone alternation at the top, with moderately to well-preserved radiolarians in the red chert beds. The overlying Jurassic - Middle Cretaceous Hocaköy Radiolarite is mainly represented by chert-mudstone alternations with some limestone interlayers. Radiolarians of the Gökdere Formation can be well correlated with that of the fauna from the Mino Terrane, central Japan and the fauna from the Queen Charlotte Islands, British Columbia, Canada. Four radiolarian zones from central Japan are recognized in the fauna obtained from Gökdere Formation such as “Praemesosaturnalis multidentatus Lowest Occurrence Zone (TR8A)” (late Norian), “Praemesosaturnalis pseudokahleri Lowest Occurrence Zone (TR8B)” (late Norian), ? “ Skirt F lowest Occurrence Zone (TR8C)” (late Norian-Rhaetian) and partly “Haeckelicyrtium breviora Taxon Range Zone (TR8D)” (Rhaetian). In comparison with the Queen Charlotte fauna, the two zones “Betraccium deweveri Zone” (late Norian) and “Proparvicingula moniliformis Zone” (early Rhaetian) are also encountered in the Gökdere Formation. Radiolarians of the uppermost part of the Gökdere Formation indicate that “Globolaxtorum tozeri Zone” defined in Queen Charlotte Islands corresponding to the late Rhaetian, is not present in the section. Five new taxa, Capnuchosphaera okayi, Bistarkum rhaeticum, Praemesosaturnalis heilongjiangensis aksekiensis, P. nobleae, Veghicyclia sanfilippoae were determined within the late Norian-Rhaetian radiolarian fauna of the Gökdere Formation in Hocaköy section.

APTIAN TO CAMPANIAN CALCAREOUS NANNOFOSSILS BIOSTRATIGRAPHY FROM THE BOTTACCIONE SECTION, GUBBIO, CENTRAL ITALY

  FABRIZIO TREMOLADA 

Abstract. Late Aptian-Campanian biostratigraphic investigations performed on calcareous nannofossils provided a refined stratigraphic resolution  of the Scisti a Fucoidi and Scaglia Formations in the Bottaccione section (Umbria-Marche Basin, Central italy). Additional bioevents such as the Last Occurrence (LO) of both Assipetra infracretacea larsonii and Rucinolithus terebrodentarius youngii and the First Occurrences (FOs) of Pararhabdolithus achlyostaurion and large Biscutum constans were detected and might be used to refine the Late Aptian-Albian biostratigraphy at low latitudes.

INTEGRATED HIGH-RESOLUTION STRATIGRAPHY OF THE LOWER OLIGOCENE TUSA TUFFITE FORMATION IN THE CALABRO-LUCANO AREA AND SICILY (SOUTHERN ITALY)

LUCA BARUFFINI, FABIO LOTTAROLI & STEFANO TORRICELLI

  Abstract. Shale samples from the volcaniclastic turbidites ascribed to the Tusa Tuffite Formation (Tufiti di Tusa Auct.) cropping out at the Canale Candela section (Calabro-Lucano boundary, southern Italy) have yielded rich, diverse and well-preserved palynomorph and calcareous nannofossil assemblages. They allow the consistent recognition of both dinoflagellate cyst and calcareous nannofossil zones previously defined in bio- and magnetostratigraphically well calibrated pelagic sequences from the central and northern Apennines. Thus they give the Canale Candela section a first order correlation to the standard chronostratigraphic scale with high precision. On this basis, an earliest Oligocene age is assigned to this succession.Poorly preserved sparse palynological and calcareous nannofossil assemblages have been recovered from the Tusa Tuffite at the type-locality (Nebrodi Mountains, NE Sicily). Hence, no biozonation is proposed for the Tusa section. The overall composition of the Tusa assemblages, however, unequivocally supports the correlation with the Canale Candela volcaniclastic turbidites.The detailed age assessment of the Tusa Tuffite outcrops investigated, as well as facies similarities, give a broad regional correlation with other Rupelian volcaniclastic successions of the Alps/Apennines system, namely the Aveto Formation belonging to the Subligurian Domain of the northern Apennines, the Ranzano Formation belonging to the Epiligurian succession of the northern Apennines and the Taveyanne Sandstones of the western Alps. In this framework, we suggest that a single regional event of rise and erosion of a volcanic arc occurred in the Alps/Apennines orogenic system during the Early Oligocene.

A COLLECTION OF FOSSIL VERTEBRATES FROM THE UPPER VALDARNO (CENTRAL ITALY) CALIBRATED IN THE END PLIOCENE TO SPAN 220,000YEARS ACROSS THE OLDUVAI MAGNETOCHRON

  GIOVANNI NAPOLEONE & AUGUSTO AZZAROLI 

Abstract. The small Faella collection of fossil vertebrates, from the Upper Valdarno (UV) continental sediments, was first assembled in the Natural history museum of Firenze over two centuries ago, reaching 13 specimens for 7 represented species, until in 1967 new finds were retrieved from the Cava Pratigliolmi clay pit. The latter were mainly collected in the lower stratigraphic levels, reaching 29 specimens for 10 species, while the position of the ancient specimens, which are among the most representative ones of the Late Villafranchian mammal age, was tentatively determined from catalogue informations. The magnetic stratigraphy of the clay pit sequence at Faella, and additional controls on their database led to assign them an age of 1775 + - 0.05° Ma. Each recent specimen was assigned a numerical age comprised in the time-span measured in the composite Faella section, extending from 45 ky prior to the onset of the Olduvai magnetochron at 1.95 Ma to shortly before the end of it at 1.77 Ma. The Faella faunal assemblage will therefore play a key role in the geochronology of the UV faunal events, which occurred during the deposition of the Montevarchi intermediate fluvial-deltaic sequence, because the specimens occupy a wide range of ages and the lowermost ones represent the earliest fauna of the late Villafranchian, close to the beginning of the Mammal zone MN 17 of the Neogene classification.. Its magnetostratigraphic date, ranging from 1995 Ma to 1.775 Ma, represents the first example in the UV fossil collections of a measured time span within one assemblage collected in stratigraphic order. The biochronological position of the late Villafranchian reconstructed in the UV, and the present example will represent a criterion for dating most  old collections, especially the classical ones, whenever a magnetostratigraphy of the units containing them will be available for correlation.

LAMPADENA IONICA: A NEW TELEOST FROM THE MEDITERRANEAN PLEISTOCENE

  ANGELA GIRONE & DIRK NOLF

  Abstract. The new species Lampadena ionica (Myctophidae, Teleostei) is described from lower and middle Pleistocene deposits of Southern Italy. In particular, L. ionica is known from the “large Gephyrocapsa” up to the Pseudoemiliania lacunosa biozone. Apparently the species became extinct before the end of the Pleistocene. Although the genus Lampadena lives only outside the Mediterranean today, it is known from the Mediterranean realm since the early Miocene. L. ionica seems to be the only species of the genus Lampadena existing in Pleistocene deposits of the Mediterranean area.