Villafranchian Research Articles

The Villafranchian carnivoran guild of Greece: implications for the fauna, biochronology and paleoecology.

Knowledge on the Villafranchian faunas of Greece was limited for a long time, but over the past 3 decades several new fossiliferous sites have been discovered and new material has been unearthed. The carnivores constitute a remarkable part of this material and their study has provided useful information for the taxonomy, chronology and palaeoecology. The Villafranchian carnivoran guild includes numerous taxa belonging to various families. Some of them are interesting as they are differentiated from the other Eurasian families. They cover the entire Villafranchian but the mass is known from the Middle to the Epi-Villafranchian (EVC). Despite the discontinuous data, they provide useful biochronological results. The coexistence of Pliocrocuta perrieri and Pachycrocuta brevirostris in the locality of Gerakarou 1 is strong evidence for the Middle Villafranchian (MVC)/Late Villafranchian (LVC) boundary. The composition of the Villafranchian carnivores suggests that the canids predominate, while the felids, hyenids and mustelids are well represented; the ursids are represented by a single taxon, the well-known Ursus etruscus, which seems to be common during the entire Villafranchian. The carnivoran guild structure and the multivariate analysis of the Greek Villafranchian carnivoran assemblages (MVC, LVC and EVC) in comparison with modern assembalges from open and closed environments indicate a relatively open landscape, which is in agreement with previous results for the Villafranchian of Greece. During the EVC there is a faunal renewal that is related to a more open and dry environment, like savannah bushland/grassland.

EUCYON MARINAE SP. NOV. (MAMMALIA, CARNIVORA), A NEW CANID SPECIES FROM THE PLIOCENE OF MONGOLIA, WITH A REVIEW OF FORMS REFERABLE TO THE GENUS

A new canid species from the genus Eucyon - Eucyon marinae sp. nov. is described from the Late Ruscinian or the Early Villafranchian of Mongolia. The species is characterised by very specific large but narrow premolars and slender mandible. The paper also provide a discussion on the ecology of the species as well as a review of Late Miocene and Early Pliocene fossil canids from North America, Eurasia and Africa referable to the genus Euston . Problems related to the taxonomy of Eucyon and other Canis-like forms are discussed.

EOSTYLOCEROS CF. PIDOPLITSCHKOI KOROTKEVITSCH 1964 (CERVIDAE, MUNTIACINAE): NEW ELEMENT IN THE NEOGENE MAMMAL ASSEMBLAGE OF LOWER VALDARNO (TUSCANY, CENTRAL ITALY)

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.

THE HOLOTYPE OF CERVALCES GALLICUS (AZZAROLI, 1952) FROM SENEZE (HAUTE LOIRE, FRANCE) WITH NOMENCLATURAL IMPLICATIONS AND TAXONOMICAL PHYLOGENETIC PROBLEMS

The remains of Cervalces ( Libralces ) gallicus (Azzaroli, 1952) from the Middle-Upper Villafranchian of Seneze (Haute-Loire, France), kept in the Paleontological Museum of the University Claude Bernard - Lyon 1, are here studied again. The remains consist of an assembled skeleton, with skull, antlers and all postcranial elements, described by Azzaroli (1952) as holotype, and in the limb bones of a second specimen, designated as cotype by the same author. The cotypeis limb bones are here attributed to the holotype, while the smaller assembled limb bones cannot be determined over the family taxonomic level, due to the bad state of preservation. The characters determining the genus Cervalces are described here and, in accordance with Azzaroli, the species C. (L.) latifrons from the Middle-Upper Pleistocene is attributed to it. All the species of the genus Cervalces show characters of cranial and facial morphology, which differ from that of present-day Alces . The narrow, deep occipital and the short nasals, not articulated with the long premaxillaris, are in this view considered apomorphic characters of Alces alces.

THE FOSSIL VERTEBRATE DATABASE OF THE NATURAL HISTORY MUSEUM OF FLORENCE AND HIGH-RESOLUTION MAGNETIC STRATIGRAPHY IN THE UPPER VALDARNO BASINS, AS A CLUE TO DATE OLD COLLECTIONS

The well established biochronologic sequence of the Villafranchian Stage in Italy is mainly based on faunal associations from the Upper Valdarno (UV) mostly collected since the late 18 hundreds, and housed in the Natural History Museum of Florence. The old collections were assembled from mostly unidentified stratigraphic levels, and their position possibly reconstructed from the surrounding geologic features. The recent magnetostratigraphic assessment of the sequence marked the earliest finds about 3.0 Ma in themid Pliocene. The end of the Pliocene was recorded by the Olduvai magnetochron in the Matassino and Poggio Rosso sites, and by other sparse assemblages. The Tasso Faunal Unit, assembled in the UV, is assigned to the Pleistocene, yet to be clarified by magnetostratigraphic data. The calibration of old, poorly timed faunas was greatly facilitatedby the computer automated catalogue of the Museum. The possibility of numerous feed-back controls enhanced any contradictory information in fossil collections and made them most fruitful for paleomagnetic calibrations: the Faella fauna and the Faella main outcrop are the ones that will be first re-examined. It is in fact now evidenced the potential role of the catalogue for accomplishing the calibration of old findings timed around the Olduvai chron, with an accuracy depending on the available record of their inferred stratigraphic levels. Numerical dates will make the old collections comparable to the new ones and both fitting into a comprehensive framework of faunal, chronologic, sedimentary evolution of the UV basin, and development in the Plio-Pleistocene climate changes.

PALEOMAGNETIC AND PALYNOLOGIC INVESTIGATIONS IN THE UPPER VALDARNO BASIN (CENTRAL ITALY): CALIBRATION OF AN EARLY VILLAFRANCHIAN FAUNA

The silty clays embedding an early Villafranchian mammal fauna of the Triversa faunal unit (f.u.) have been paleomagnetically and palynologically studied in a continuous sequence exposed in the Santa Barbara quarry.The study has allowed to date the earliest occurrence in Italy of a faunal assemblage of this unit and to define the corresponding climatic conditions. The sampled section has provided a magnetic polarity sequence of the late Gauss,where the fossiliferous layer fits the Kaena reversed interval.Its age of ca. 3.1 Ma,during subtropical climate conditions correlatable to the Reuverian of Netherlands, suggests an older age for the beginning of the Villafranchian, possibly associated to a more dramatic scenario able to trigger the faunal turnover.

Stratigrafia e sedimentologia dei depositi fluviolacustri plio-pleistocenici dell'area nord occidentale del Valdarno superiore (Toscana)

In this paper are exposed the results of statigraphical and sedimentary analysis carried out in the north-western side of the Plio-Pleistocene fluviolacustrine upper Valdarno basin. The deposits of Montevarchi and Torrente Ciuffenna Successions were mapped. These deposits originated during the second and third phases, respectively, of a three-phases sedimentary history. They are separated by an erosional surface extended on the whole basin. According to the existing literature the chronostratigraphic gap extends from the upper part of the Early Pleistocene to the lower part of the Middle Pleistocene. The studied Successions can be classified using the unconformity-bounded stratigraphic units nomenclarure. The Sinthem term is proposed replacing the Succession term. The sedimentary evolution of the studied area is reconstructed starting from the Upper Pliocene. During the deposition of the Montevarchi Sinthem, a fluviolacustrine setting developed in this area. Facies analysis made it possible to recognize coarse-grained fan deltas prograding into a shallow lacustrine environment. The fan delta succession records significant tectonically induced variations of the clastic imput. The lower part of the fan delta succession is characterized by calcareous-arenaceous conglomerates of northwestern provenance. A subsequent rise of the Pratomagno chain lead to a predominance of arenaceous clastic material of eastern provenience. In the fan deltas deposits mammal fossils belonging to the Late Villafranchian and probably to the Early Galerian have been recovered. According ro these data the fluviolacustrine succession developed until the upper part of Lower Pleistocene. The unconformity separating the second and third phase may cover a smaller span of time in the studied area. In the third depositional phase an alluvial setting replaced the fluviolacustrine one previously developed. The alluvial fan succession building up the Torrente Ciuffenna Sinthem, filled the basin during the Middle Pleistocene. The erosion of the northern threshold closing the basin for the most part of the Pleistocene, induced in the Late Pleistocene the beginning of the erosive phase. On the whole the depositional evolution of the studied area was tectonically controlled. The climatic influence over the sedimentation was of lesser importance.

The genus Ursus in Eurasia: dispersal events and stratigraphical significance

On the basis of the results of former studies by the present authors five main groups of bears are recognized: Ursus gr. minimus - thibetanus (black bears), Ursus gr. etruscus (etruscan bears), Ursus gr. arctos (brown bears), Ursus gr. deningei - spelaeus (cave bears) and Ursus gr. maritimus (white bears). Black bears seem to have disappeared from Europe during the Late Pliocene, immigrated again at the beginning of the Middle Pleistocene, and definitively died out in Europe at the beginning of the Late Pleistocene. Etruscan bears occur more or less contemporaneously in the southern areas of Europe and Asia during the Late Pliocene. The Asian branch apparently became extinct at the end of this period, while the European stock survived, giving rise to more advanced representatives during the Early Pleistocene. Brown bears seem to have originated in Asia. This group dispersed widely in holoarctic areas diversifying into a great number of varieties. They reached Europe presumably at the very end of the Early Pleistocene. The arrival of brown bears in Europe is a crucial event, which approximately coincides with the great faunal turnover which marks the Early-Middle Pleistocene transition. Brown bears replaced the etruscan bears, typical of the Villafranchian faunal assemblages, and gave rise to the cave bear line. Cave bears were very successful in Europe during the Middle and Late Pleistocene and disappeared at the end of the last glaciation or even at the very beginning of the Holocene. White bears presumably originated from northern Eurasian brown bear populations during the Late Pleistocene.

The Villafranchian in the Massif central in France

The Villafranchian in the Massif central in France

Les croutes calcaires et gypseuses en Algerie: Formation et age

The limestone and gypsum crusts studied from Algeria belong to five main categories different in origin and in ages. In the formation of each water was always the vehicle for the material deposited. Pedologic and geologic phenomena intervened in the formation of the crusts. A study of the composition and mode of formation of the crusts indicates that the pulverulent limestones were not formed after the Villafranchian; the most favorable period for the formation of red loams with pulverulent limestone nodules began toward the end of the Villafranchian and terminated before the Sicilian; formation of the zonal crusts began soon after the maximum period of formation of the preceding type and lasted until the Tyrrhenian I. The Tyrrhenian II marks the end of the deposition of this type of crust and pulverulent gypsums were then formed and incrustations appeared as nodules and pseudomycelia.