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.

Biochronology,paleobiogeography and faunal turnover in western Mediterranean Cenozoic mammals

Cenozoic terrestrial mammals from Sardinia contribute substantial information for reconstructing the complex his-tory of the western Mediterranean.The occurrence of endemic perissodactyls in Eocene marine and marsh deposits suggests the existence of ecological or physical barriers between the Corso-Sardinian massif and the Iberian-Occitanic area.At the end of the Oligocene,isolation of Sardinia was almost complete,although a migration from Europe occurred at the beginning of the Early Miocene,as indicated by the unbalanced endemic fauna from Oschiri.During the Late Miocene,the Tusco-Sardinian palaeobioprovince came into existence as an isolated region inhab-ited by the quite diversified,but notably endemic,Oreopithecus fauna.Sardinia was definitely isolated from Tuscany by the Messinian,but temporary connections with the European mainland possibly allowed the colonization of forerunners of some Sardinian Pliocene taxa.During the Plio-Pleistocene,Sardinia maintained permanent isolation.However,sea level drop,resulting in a relatively short distance between Sardinia and the European mainland,allowed different migratory events.From the Late Pliocene to the Late Pleistocene–Holocene,two main mammalian faunal complexes(FC)can be recognized:the Nesogoral FC(Late Pliocene-Early Pleistocene)and the Microtus(Tyrrhenicola)FC(late Early Pleistocene–Early Holocene).At the transition from Nesogoral to Microtus(Tyrrhenicola)FC,approximately 47%of the genera and 76%of the species disappeared,while approximately 58%of the genera and 71%of the species appeared.A noticeable turnover followed the arrival of Neolithic man and his accompanying fauna.Nonetheless,Praemegaceros was still present at about 7000 years BP,while Microtus(Tyrrhenicola)and Prolagus are respectively recorded in the Bronze and Iron Ages.

Character, Age and Ecology of the Hezheng Biota from Northwestern China

The Hezheng area Of Gansu Province produces the most abundant mammal fossils in China as well as the whole Eurasia, and it also produces other Cenozoic fossils of different animals and plants. Therefore, all of them are named the Hezheng Biota. Mammals are very sensitive to environmental changes, and thus the evolution of mammalian faunas in the Hezheng area reflects the strong uplift of the Tibetan Plateau during the Late Cenozoic, which dramatically affects environmental changes. In the Hezheng area, micromammals are not very rich, but some of them still are important. It is relatively uncommon that three primates are found from the Middle Miocene and the Early Pleistocene deposits. Since the Middle Miocene, carnivores have become important components in the ecosystem of the Hezheng area, and dominated in the Early Pleistocene. The Middle Miocene is a time of high diversity for Proboscidea, characterized by shovel-tusked elephants. Perissodactyls in the Hezheng area are very abundant, especially Late Oligocene and Late Miocene rhinoceroses as well as the Late Miocene and Early Pleistocene horses. From the Middle Miocene, artiodactyls became important components of the mammalian faunas, especially bovids.

Early Paleogene stratigraphic sequences,mammalian evolution and its response to environmental changes in Erlian Basin,Inner Mongolia,China

Paleogene strata in the Huheboerhe area,Erlian Basin,Inner Mongolia,China have been subdivided into three lithological units:the Nomogen Formation,the Arshanto Formation,and the Irdin Manha Formation.At least 12 mammal-bearing horizons have been recognized in these formations,of which 4 in the Nomogen Formation,6 in the Arshanto Formation,and 2 in the Irdin Manha Formation.Recent investigation proved that the "Houldjin Formation" recognized in this area by the Central Asiatic Expeditions(CAE) of the American Museum Natural History in the 1920s is actually the Irdin Manha Formation,while the "Irdin Manha Formation" of CAE is the Arshanto Formation.A recent paleomagnetic study suggests that the upper part of the Nomogen Formation is early Eocene in age and the Arshanto Formation is mainly early Eocene rather than middle Eocene as previously thought.The Gashatan,Bumbanian,and Arshantan land mammal ages are correlated respectively to the Thanetian,the early Ypresian,and the middle Ypresian through earliest Lutetian of the Geological Time Scale.These land mammal ages are also correlated with the late Tiffanian through Clarkforkian,the early Wasatchian,and the middle-late Wasatchian and most of the Bridgerian of the North American Land Mammal Ages.During the early Paleogene,the mammalian history of the Erlian Basin was dominated by the appearance of new mammalian families and the replacement of a variety of genera and species,corresponding to the gradual climatic changes during this time period.The abrupt emergence of several modern mammalian orders at the beginning of the Eocene is probably related to extreme climatic warming in relation to the Paleocene-Eocene Thermal Maximum.

Recent Advances in the Small Mammal Biostratigraphy and Magnetostratigraphy of Lanzhou Basin

The consensus view among geologists is that the Lanzhou Basin sequence of sedimentscontains the Oligocene/Miocene boundary, but where this occurs is unknown. Indeed, this is thecrux of the issues concerning mid-Tertiary paleontology in Asia: what fauna corresponds with thistime? What turnover events or distinctive taxa signal the beginning of the Miocene epoch? Onceknown, this will be of broad usefulness because vertebrate-bearing deposits are widespread in Asiaand can be used to date basin sediments. Lanzhou and other basins permit a means of correlating tothe time scale by using fauna and paleomagnetic data locally, and ultimately radiometric data fromdistant localities, to develop a precise biochronology. Herein, we summarize faunal constraints,primarily those of small mammal taxa, on correlation of the Lanzhou magnetozone sequence to themagnetic time scale. We conclude that the lower part of the Xianshuihe Formation contains theOligocene/Miocene boundary, and that the top of the formation, both in the south and north partsof the basin, is middle Miocene in age. Rodents from lower white sand units of the XianshuiheFormation, correlate to the Xiejia assemblage of the Xining Basin, Qinghai Province, and are early,but not earliest, Miocene age. The implication for rodent faunas of the epoch boundary is that theyretained a mainly "Oligocene" composition, and that other presumed late Oligocene assemblagesmay be, in fact, early Miocene in age. The Lanzhou appearance of Proboscidea is 19-18 Ma, asexpected.