Danilo Torre

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).

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.

Taxonomic remarks on the South American Mastodons referred to Haplomastodon and Cuvieronius

New mastodon finds collected in the Province of Carchi (Northern Ecuador) give further evidence that in South America Haplomastodon and Cuvieronius are monospecific. Of all the specific names referred to the genus Haplomastodon, only chimborazi must be considered valid as it alone was based on significant diagnostic material. As far as the genus Cuvieronius is concerned a new type species, Cuvieronius tarijensis, is proposed as the type specimen of Cuvieronius hyodon likely belongs to Haplomastodon.

Hypothesis on the cause of extinction of the South American mastodonts

Abstract Paleontological, geomorphological and sedimentological investigations on the Cangahua Formation in the Interandean depression of Northern and Central Ecuador have provided information on the evolution of the Andean paleoenvironment during the Late Pleistocene. Pyroclastic and windblown sediments were deposited during cold and dry phases of the last glaciation, interrupted many times by the development of forest-steppe and steppe paleosoils during interstadials. An erosional phase which closed the Cangahua sedimentation was followed by the deposition of colluvial sediments, characterized by a high number of minor pedogenetic episodes. The colluviums are confidently referable to the Holocene. The upper part of the Cangahua Formation is rich in mammal fossils and is probably referable to the Last Glacial Maximum. The fossiliferous sequences suggest that mastodonts disappeared before mylodonts and equids. We hypothesize that the increased cold and aridity of the Last Glacial Maximum, which deeply affected the Cordillera, caused the extinction of most of the megafauna and the mastodonts seem to have been the most sensitive to the environmental degradation. The final history of South American mastodonts, represented by Haplomastodon and Stegomastodon, spans the latest Pleistocene and probably the earliest Holocene. Haplomastodon was dispersed in the highlands within the tropical belt and Stegomastodon in plains of the southernmost part of Brazil, in Paraguay, Uraguay, Argentine, central and northern Chile. Both Haplomastodon and Stegomastodon suffered the same negative effects of the Last Glacial Maximum when their habitats underwent intense desertifications under dry and cold conditions. They disappeared in a mosaic way in the course of the latest Pleistocene, the last representatives probably surviving in favorable restricted areas where however the considerably increased selective pressure was in the long run devastating. In our opinion the human impact was not a determinant in causing mastodont extinction.

New Haplomastodon findsfrom the Late Pleistocene of northern Ecuador

Abstract New mastodon remains were collected in the Carchi Province, northern Ecuador. The levels from which the fauna was collected are referred to the Late Pleistocene (Late Lujanian Mammal Age). On the basis of this fossil material, we conclude that probably only one species of Haplomastodon was present in Ecuador, most of tropical South America, and temperate southwestern Brazil. At the present state of knowledge we feel it convenient to classify the different Haplomastodon demes of this faunal province as Haplomastodon ex gr. waringi ( Holland , 1920 ).

Cesi, an early Middle Pleistocene site in the Colfiorito Basin (Umbro-Marchean Apennine), central Italy

Near the village of Cesi, at the head of the Chienti River, in the Colfiorito Basin (Umbro-Marchean Apennines, central Italy), fluvio-lacustrine deposits have yielded mammal fossil remains. The results of a multidisciplinary investigation indicate that the vertebrate-bearing sediments date about 700 ka and accordingly provide a fossil assemblage for the Middle–Late Galerian. Palynological investigations carried out from sediments underlying the fossiliferous level suggest predominantly cold and dry conditions, whereas the fauna suggests a slight climatic amelioration towards cool and moist conditions in the uppermost part of the sequence.

Species interrelationships and evolution in the pliocene endemic faunas of apricena (Gargano Peninsula-Italy)

Summary Preliminary observations allow to advance hypotheses on evolutive strategies of three coexisting species of the murid Microtia in Pliocene fissure fillings of the Gargano Peninsula.

STEGOTETRABELODON (PROBOSCIDEA, ELEPHANTIDAE) FROM THE LATE MIOCENE OF SOUTHERN ITALY

Abstract This paper describes new remains of Stegotetrabelodon from Southern Italy, the first evidence of this genus from Eurasia. The material consists of a mandible and a lower tusk fragment collected at Cava Brunia, Cessaniti (Vibo Valentia, Calabria), in late Tortonian Clypeaster-bearing coastal sands. The morphology of the mandible and teeth conforms to the Libyan species S. syrticus, to whom the Italian specimen is referred. The occurrence of this elephantid and other mammal species with african affinity at Cessaniti, suggests that the Calabria-Sicily area was a northern extension of the African continent. The Cessaniti elephantid adds new information on the morphological variability of Stegotetrabelodon and provides clues of an early distribution of the genus since the Tortonian.

Celadensia grossetana nov. sp. (Cricetidae, Rodentia) from the late Turolian Baccinello-Cinigiano Basin (Italy)

Abstract A cricetid mandible from the late Turolian V3 faunal assemblage of the Baccinello - Cinigiano basin is here referred to a new species of the sub-family Baranomyinae, Celadensia grossetana. Several genera are very similar in this subfamily of cricetids, especially in the M/1s morphology. Though the fossil specimen at our disposal is hightly differenciated, we prefer not to increase the number of genera thus Passigning it to the genus Celadensia. As a matter of fact Celadensia nicolae from the early Pliocene of Teruel basin (Spain) is the species showing the closest similarities with the fossil from Baccinello V3.