Augusto Azzaroli

BIOCHRONOLOGY OF SELECTED MAMMALS, MOLLUSCS AND OSTRACODS FROM THE MIDDLE PLIOCENE TO THE LATE PLEISTOCENE IN ITALY. THE STATE OF THE ART

The Authors have elaborated four range charts of mammalian (large and micro), molluscs and fresh-water and brackish ostracodes faunas, for the selected Plio-Pleistocene fossiliferous localities of the Italy. A new Mammal Age (Aurelian) correlatable to late Middle and Late Pleistocene has been defined. Inside this age two Faunal Units (Torre in Pietra and Vitinia) have been defined as characteristic for Early and Middle Aurelian, while no gisements have been chosen for the late Aurelian. Biochronological units are calibrated on magnetostratigraphic and isotopic scales and by radiometric datings.

Late pliocene to early mid-pleistocene mammals in Eurasia: Faunal succession and dispersal events

Abstract Four major dispersal events mark European Villafranchian and Galerian faunas (about 3.2-0.4 Ma). The beginning of the Villafranchian is evidenced by the arrival of Leptobos and of large cervids and felids; the fauna still retains typical forest elements: Mammut, Tapirus, etc. The Elephant-Equus event (about 2.5–2.6 Ma) brought in grassland elements (elephant, horse) while several forest dwellers disappeared. The massive arrival of a primitive wolf, a large hyaena and Leptobos etruscus approximately marks the Plio-Pleistocene boundary (Wolf event, about 1.7 Ma). This was followed by a new wave of prairie fauna: Praeovibos, “Leptobos” vallisarni, Allophaiomys, Canis arnensis (a coyote), Canis falconeri (possibly a lycaonid); Cervalces and Hippopotamus also arrived at this time. The Villafranchian-Galerian transition saw a total faunal turnover, with massive extinctions and new, previously unknown adaptations (end-Villafranchian event, 1.0-0.9 Ma). The late Pleistocene and living fauna of Eurasia took its origin at this time. Mammalian stratigraphy of Asia is more poorly known but faunas are easily correlated with European ones and the end-Villafranchian event is clearly recognised. Faunal events are correlated with climatic and physiographic changes (late Himalayan orogeny).

Quaternary mammals and the “end-Villafranchian” dispersal event — A turning point in the history of Eurasia

The history of land mammals is characterized by “dispersal events”, i.e. short periods of rapid intercontinental migrations and faunal replacements. One of these, the Elephant-Equus event of Lindsay et al., may be dated somewhere between 3 and 2.5 Ma. A second event, the “Wolf” event, may fall near 1.7 Ma. The “end-Villafranchian” event is discussed in detail. It may be dated between 1.0 and 0.9 Ma and is marked by a practically total rejuvenation of the fauna, with the appearance of new types of adaptation, unknown in the Villafranchian. This faunal revolution is easily recognized all over Eurasia and is accompanied by wide-ranging changes in climate and vegetation. This whole sequence of phenomena may have been triggered by extensive tectonic movements in the mountain belts of central and southern Asia.

A one-million-year-old Homo cranium from the Danakil (Afar) Depression of Eritrea

One of the most contentious topics in the study of human evolution is that of the time, place and mode of origin of Homo sapiens. The discovery in the Northern Danakil (Afar) Depression, Eritrea, of a well-preserved Homo cranium with a mixture of characters typical of H. erectus and H. sapiens contributes significantly to this debate. The cranium was found in a succession of fluvio-deltaic and lacustrine deposits and is associated with a rich mammalian fauna of early to early-middle Pleistocene age. A magnetostratigraphic survey indicates two reversed and two normal magnetozones. The layer in which the cranium was found is near the top of the lower normal magnetozone, which is identified as the Jaramillo subchron. Consequently, the human remains can be dated at ∼1 million years before present.

Terrestrial mammals and land connections in the mediterranean before and during the messinian

Abstract Terrestrial mammals provide evidence for repeated land connections between Europe, several Mediterranean islands and northern Africa during the Tertiary. The distribution of mammals substantiates palaeogeographic reconstructed postulated by tectonic analysis, according to which Mallorca, Sardinia and the Calabro-Peloritan massif were connected with southern France and Spain in the Eocene and early Oligocene. A connection of Mallorca and possibly Sardinia with Africa in the Oligocene is also shown. In the middle Miocene a migration took place from the Balkans to the Gargano promontory, which subsequently became an island. At this age faunal migrations between Africa, Spain and Italy may possibly have taken place, but this has not been definitely proved. During the Messinian, faunal interchange occurred between Morocco and Spain and between Tunisia and Sicily; other faunal migrations took place between the European mainland, the Balearics and Sardinia. The occurrence of taxa of African origin in Greece suggests a late Miocene faunal interchange directly across the eastern Mediterranean. However, most of the taxa were also recorded from Anatolia, so that the migration could have taken place into the Mediterranean from the east. A notable exception is Hystrix, first recorded from the Vallesian of Morrocco (Marceau) and not recorded from Anatolia.

On the possible origin of the Giant Deer genus Megaceroides

The Giant Deer genusMegaceroides, originally proposed as a subgenus by Joleaud in 1914 and redefined by Azzaroli in 1979, was presumably derived from the Chinese, late PlioceneEucladoceros boulet, through an intermediate form from the early Pleistocene of the Kuban valley, North of the Caucasus. A newly discovered species from the latest Villafranchian of Central Italy is a primitive representative ofMegaceroides which still retains several ancestral features.RiassuntoMegaceroides, un genere di cervi giganti originariamente descritto da Joleaud nel 1914 come sottogenere e ridefinito da Azzaroli nel 1979, sembra discendere daEucladoceros boulet, del Pliocene superiore della Cina, attraverso l’intermediario di un cervide del Pleistocene inferiore del bacino del Kuban, a Nord del Caucaso. Una specie rcentemente scoperta nel Villaifranchiano terminale dell’Italia centrale è un rappresentante primitivo diMegaceroides e conserva vari caratteri ancestrali.

Miocene Vertebrate remains from Scontrone, National Park of Abruzzi, Central Italy

In the outskirts of Scontrone, in the National Park of Abruzzi, the uppermost beds of marine sequence outcrops have yielded fossil remains of reptiles (crocodiles and chelonians) and continental mammals (a carnivore and perhaps four artiodactyls). The vertebrate-bearing sediments are tentatively dated to the Tortonian or Messinian. Artiodactyls point to a relationship with the Early Pliocene endemic fauna of the Gargano promontory, thus raising an intriguing problem of Late Neogene paleogeography.RiassuntoI termini superiori di una serie marina che affiora nei pressi di Scontrone, nel Parco Nazionale degli Abruzzi, hanno restituito resti tossili di rettili (coccodrilli e cheloni) e mammiferi (un carnivoro e forse quattro artiodattili). I livelli a vertebrati sono al momento attribuiti al Tortoniano-Messiniano. Gli artiodattili indicano una relazione con la fauna endemica del Pliocene inferiore del promontorio del Gargano, sollevando cosi un interessante problema di paleogeograiia del tardo Neogene.

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.

THE POGGIO ROSSO LOCALITY CALIBRATED TO THE END-PLIOCENE AND ITS SIGNIFICANCE FOR DATING THE LATE VILLAFRANCHIAN MAMMAL FAUNAS OF THE UPPER VALDARNO, CENTRAL ITALY

A rich deposit of mammals was discovered in September 1995 at Poggio Rosso, the hill-top of the Matassino clay pit, in the Upper Valdarno Basin, 30 m above another deposit whose local fauna was assembled 30 years earlier. This latter provided the Matassino Locality, assigned to the beginning of the late Villafranchian Mammal Neogene age on the basis of its affinity with the Olivola faunal unit, which was also taken to represent the earliest assemblage in the Pleistocene. The paleomagnetic record in the short section across the Matassino Locality revealed the Olduvai chron, which was imprinted also in the fossil-bearing stratum of Poggio Rosso, so constraining both their ages to the latest Pliocene. The Poggio Rosso fauna, yet to be paleontologically determined, and the other late Villafranchian faunas collected in the Upper Valdarno from the Montevarchi complex fit a similar time span. Therefore, their magnetostratigraphically calibrated ages provide the time constraints for the biochronological relationships between faunas which can be tuned to several tie points for numerically evaluating their diversification steps during the whole Olduvai chron and shortly out of it.

Cainozoic mammals and the biogeography of the island of Sardina, Western Mediterranean

Abstract Analysis of the Sardinian and other faunas of terrestrial mammals of the western Mediterranean provides evidence that Sardinia was connected with Europe at least at five different times during the Tertiary and early middle Pleistocene, and once with northern Africa, in the late Oligocene, through the Balearics. An attempt is made to reconstruct the palaeogeography of the western Mediterranean in the light of present knowledge of its structural evolution during the Tertiary. Owing to its complicated history, the Sardinian fossil fauna is richer than the faunas of other Mediterranean islands. The native mammalian faunas of Sardinia are now extinct and have been replaced by mammals imported by man.