Previous chronological arrangements of South American Quaternary land mammal faunas are appraised on the basis of current geological and paleontological data. Three South American late Pliocene-Pleistocene land mammal ages are conventionally recognized, from oldest to youngest, the Uquian, Ensenadan, and Lujanian ; all are defined on Argentine faunas.

     The Uquian is based fundamentally and historically on the fauna from the Uquía Formation in Jujuy Province, northwestern Argentina. Important known formations in Argentina yielding Uquian Age faunas include the sub-surface Puelche Formation (or Puelchense) near the city of Buenos Aires, and the Barranca de Los Lobos and Vorohué Formations between Mar del Plata and Miramar, Buenos Aires Province. A tentative subdivision is propos-ed for the Uquian into three subages based on knowledge of the Mar del Plata-Miramar sequence, from oldest to youngest, the Barrancalobian, Vorohuean, and Sanandresian. In Argentina the Uquian is presently marked by the first known record of Scelidodon, Hydrochoeropsis, Ctenomys, Canidae, Ursidae, Gomphotheriidae, Equidae, Tapiridae, Camelidae, Cervidae, and the last known record of Thylatheridium, Thylophorops, Dankomys, Eumysops, Pithanotomys, Eucoelophorus, Hegetotheriidae, Sparassocynidae, and Microtragulidae.

The Ensenadan Age is based on the fauna from the Ensenada Formation near the city of Ensenada, Buenos Aires Province. In Argentina the Ensenadan is marked by the first known record of Lomaphorus, Neothoracophorus, Plaxhaplous, Cavia, Lyncodon, Lutra, Galera, Smilodon, Dicotyles, Lama, Vicugna, the last known record of Orthomyctera, and the only known record of Brachynasua.

     Typícal beds of late Lujanian Age in Argentina consist of fluvial deposits occupying stream channels, and shallow basins, often incised into beds of early Lujanian (i.e. Bonaerian of early workers) and Ensenadan Age. The Lujanian Age is based on a fauna from beds along the Rio Luján, about 65 km west of the city of Buenos Aires, Buenos Aires Province. The Lujanian in Argentina is marked by the first record of Equus, Chlamyphorus, and Holochilus, and the last record of Megatherioidea, Glyptodontoidea, Arctodus (=Arctotherium), Smilodon, Litopterna, Notoungulata, Proboscidea, Equidae, Morenelaphus, and Palaeolama.

   These land mammal ages are often difficult to recognize in other South American countries. The compositions of South American Pleistocene faunas vary with the environment. Some taxa were widely distributed in fossil deposits throughout the continent, but their occurrences need not reflect synchroneity. This is a result of changing climates and habitats in time. Consequently, proposed intracontinental correlations need confirmation based on magnetostratigraphy and a radioisotope time scale. Paleontologic characterizations of these land mammal ages (i.e. first and last record, and guide fossils) are useful for much of Argentina, but extensions to most of the other parts of South America are at best tenuous.

The majority of known non-Argentine Pleistocene faunas are believed to be Lujanian in age. Possible non Argentine early Pleistocene (Uquian) faunas include Ayo Ayo and Anzaldo in Bolivia, and Cocha Verde in southern Columbia. A possible middle Pleistocene (Ensenadan or early Lujanian) fauna is the Chichense of Ecuador. Paleomagnetic and radioisotopic date (MacFadden et al., 1983) clearly indicate that the greater part of the Tarija fauna (Bolivia) is Ensenadan in age.

  The end of the Pleistocene and beginning of the Holocene in South America is marked by extinction of nearly all large mammalian herbivores and their specialized large predators. Radiocarbon age determinations suggest that large scale extinctions of megafauna occurred between 15,000 and 8,000 yrs. B.P. (years before present). 

The analysis of oxygene isotope variations as well as paleobotanical data suggest that the Oligocene/Miocene boundary corresponds to a transitional period marked by floristical and climatic variations. During this period, the pyreneo-alpine tectonics has contribued to modify the geography and western Europe landscapes. Faunal changes (appearances, extinctions, migrations) are observed in different mammalian groups, notably in the rodents. A study of the evolutionary trends and patterns in paleogene rodents is involved for the period ranging from level MP 28 of the Late Oligocene to the Early Miocene, including the Oligo-Miocene boundary.
The Rodents fauna from the sites of Venelles (Bouches-du-Rhône District, France) and Thezels (Lot, France), previously mentionned in litterature, have been studied. The first description of the Eomyidae of La Milloque (MP 29) has been completed. These faunas are compared to those from various localities dating from the considered period. In La Milloque, a new representative of the Eomys species is described next to a form close to Rhodanomys hugueneyae ENGESSER, 1987. It is the Eomys milloquensis nov. sp., the likely descendant of Eomys quercyi COMTE & VIANEY-LIAUD, 1987. Two new species are also described in Thezels: Eucricetodon thezelensis nov. sp., resulting from a likely and local evolution of Eucricetodon praecursor (SCHAUB, 1925) from La Milloque, which, in the same geographic area, could be at the origin of Eucricetodon hesperius ENGESSER, 1985 from Paulhiac. Plesiosminthus admyarion nov. sp., quite distinct from Plesiosminthus schaubi VIRET, 1926, which announces Plesiosminthus myarion SCHAUB 1930. Venelles 'Plesiosminthus schaubi population is considered as a sub-species, named Plesiosminthus schaubi meridionalis nov. subsp. New phylogenetic patterns are proposed. Among the Eomyidae, a quantification of various features of the M1-2/ crown (hypsodonty, degree of abrasion, occlusal angle, state of development of the I and V anticlines), and a comparison with the occlusal diagram of the other teeth among various other populations allows a more efficient separation of Eomys and Rhodanomys genera. In Western Europe, and within this period, it finally does not seem possible to gradually connect the genus Eomys to the genus Rhodanomys. The evolution of the Eomys quercyi - milloquensis lineage seems to underline a similar evolution to that which may have led from the Eomys to the Rhodanomys form. The latter which appears totally accomplished at level MP 29 of the Oligocene is considered as an immigrant. If we compare the most representative species of the Venelles, Thezels, and Coderet sites, (i.e. Rhodanomys, Eucricetodon, Adelomyarion, Peridyromys, Plesíosminthus), it becomes impossible to confirm their biochronological separation. The noticeable differences between the populations may be interpreted as geographical variations. An explanation to these variations, and to fauna's evolution during the Late Oligocene and Early Miocene can be found in the environmental modifications, supported by isotopic, paleobotanical and sedimentologic analysis. A tentative reconstruction of the environments is attempted by the cenogram method. The analysis of the fluctuations of fauna's diversity shows variations which may be correlated to a drop in temperature at MP 29, during the Late Oligocene, followed by an increase in temperature along with an aridity phenomenom, during the basal Miocene (MN O).The confrontation of various methods give the opportunity of reconstituting and comparing the evolution of the environment of three sequences of sites chosen from different regions. Ecological affinities of various rodents' species are being examined. It is possible to consider that the integration of all the conclusions resulting from this study should lead to an explanation to the evolution of rodents for the period around the Oligocene-Miocene boundary. The site of Coderet- level 3- would be posterior to the latter, at the beginnig of the Miocene, and would mark the level MN 0 of the Aquitanian.

  

Study of pantolestid mammals from the late Ypresian locality of Prémontré (reference level MP 10) allows the recognition of three genera: Palaeosinopa. Pantolestes and Premontrelestes n. gen. Pantolestes, up to now only recorded from North America, is represented by P. sabatieri n. sp. Premontrelestes n. gen., represented by the type species P. duchaussoisi n. sp., is compared with Pantolestes and Buxolestes. The latter, known from middle Eocene sites in Europe, has not been recognized at Prémontré. Two other taxa, the first of which is close to Pantolestes and the second of Premontrelestes n. gen. are left in open nomenclature.    

The litoptem Proterotheriidae are extinct endemic South American ungulates frequently used as an example of evolutionary convergence with the horses. They were considered to be exclusively Tertiary representatives with the youngest record being in the late Pliocene, before the appearence of the equids and cervids during the Great American Interchange. Two undoubted Pleistocene records in Argentina and the specimen here described from Uruguay, confirm the persistence of the proterotherids into that period. In the Quaternary, these ungulates are found outside the typical pampean region and probably were confined to a few northern and warmer more forested relictual microhabitats.

  

Extensive sampling of the Siwalik deposits of the Potwar Plateau of northem Pakistan and from the Zinda Pir dome of central Pakistan has produced a fossil record of Miocene ctenodactylids that can be correlated with the paleomagnetic time scale. The early Miocene Prosayimys flynni (n. gen., n. sp.) is recognized as the first ctenodactylid in the Indian subcontinent. Prosayimys is ancestral to Sayimys. From the late early Miocene to the early late Miocene, there is an anagenetic succession of three species of Sayimys: S. cf. S. intermedius, S. sivalensis, and S. chinjiensis (n. sp.). Sayimys chinjiensis gave rise to the late late Miocene S. perplexus. A second lineage is represented by Sayimys minor, S. sp. A, and S. sp. B. 

 A new genus of hystricognath rodent with two new species, Soriamys gaimanensis and Soriamys ganganensis, from the Colhuehuapian Age (Early Miocene), Sarmiento Formation, of Patagonia is described. The first species comes from the south barranca of the valley of Rio Chubut, near Gaiman locality (Chubut Province). It is known through a great number of dental remains in different stages of wear. The teeth are protohypsodont, with cement in the principal valleys. P4 are simpler, more oval inoutline and without a differentiated hypocone-hypoflexus. Upper molars are pentalophodont in early stages of wear and become bilobated in middle and advanced stages; M3 have a temporary third posterior lobe due to the maintenance of the braquiflexus on the posterior wall of the tooth. Lower teeth have a completely asymrnetrical pattern in relation to the uppers. The molars are trilophodont, with only one complex crest in the trigonid composed of the fusion of the anterolophid and mesolophid. The dp4 have a derived pentalophodont pattern due to the loss or fusion of the mesolophid and the development of an accessory transverse crest between the anterolophid and metalophid. The second species is known through a complete skull and jaw and other skull fragments with the dentition, proceeding from Pampa de Gan Gan, Chubut province. Respect to the first species, the teeth are higher crowned, with an earlier occlusal simplification and a third posterior lobe of M3 more developed and persistent. The skull and jaws show many chinchilloid characters, such as jugal bone with an ascending process, concave palate, very prominent dorsal shelf of the masseteric fossa, nasolachrymal duct opened laterally on the maxillary and very developed lateral mandibular fossa. Moreover, Soriamys is closely related to Cephalomys by sharing a similar asymmetric dental pattern and other dental and mandibular characters. These two genera constitute a natural group, the Cephalomyidae, with peculiar dental characters, like the asymmetric pattem of the upper and lower teeth; Cephalomyopsis, and probably Litadontomys, can be considered part of this group. Scotamys and Perimys constitute a distinct lineage (the Neopiblemidae or Perimyidae), more closely related to the chinchillids. Many characters shared by cephalomyids, eocardiids and caviids suggest a closer affinity between the Chinchilloidea and the Cavioiidea as a whole. Abrocoma shows also an asymmetric dental pattern and other chinchilloid features that suggest some degree of relationship with the cephalomyids, still not well determined. 

New records of terrestrial mammals from the Qasr el Sagha Formation, Fayum Depression, Egypt are reported, and the stratigraphic occurrences of these fossils noted. These include additional specimens of Moeritheríum, Barytherium, and anthracotheres, as well as the oldest record of a hyracoid in the Fayum.These Eocene mammals occur almost exclusively in the alluvial deposits of the Dir Abu Lifa Member of the Qasr el Sagha Formation and show close affinities to the faunas from the lower sequence of the Jebel Qatrani Formation. There is no evidence of a more marked faunal discontinuity between the Qasr el Sagha and Jebel Qatrani Formations than there is across any of the three major breaks in sedimentation that exist within the Jebel Qatrani Formation. The faunal similarities between fossils of the lower sequence of the Jebel Qatrani Formation and of the upper part of the Qasr el Sagha Formation is consistent with recent paleomagnetic dating that suggests that these rocks differ in age by only one to two million years. 

The fauna from three new rodent localities (Castelmaurou, Grépiac-carrière et Grépiac-rive gauche) from Oligo-Miocene molasses of the Toulouse area is described. The one from Colomiers is completed. 11 species belonging to 4 families (Cricetidae, Eomyidae, Gliridae, Sciuridae) are present. The Miocene localities of Grépiac-carrière and Colomiers are correlated with Balizac, La Brète, Lambert and Lespignan. Grépiac-rive gauche is just a little older than these sites. Castelmaurou is somewhat younger than La Milloque and belongs to Oligocene. 

Several endemic deer remains from the Middle Pleistocene deposits of the Castiglione cave (Oletta, Haute-Corse) are examined here. A morphometric analysis allows to relate them to a new insular subspecies Cervus elaphus rossii. The bones were compared with those of the mainland early Middle Pleistocene subspecies Cervus elaphus acoronatus Beninde and the European species Cervus elaphus Linné (Late Middle Pleistocene and Upper Pleistocene forms (continental and insular)). The Castiglione fossil shows peculiar morphofunctional features in its appendicular skeleton suggesting a morphological convergence with certain Bovidae. 

The Causses" is a near 3400 km2 large plateau located in the south of France. Here the first dinosaur footprints where found in 1935. After this, this area has yielded an ever-increasing number of ichnites now in excess of 500 specimens. These latter, 15 to 50 cm long, tridactyl or tetradactyl footprints of generally biped animals, were discovered at the surface of Hettangian to lower Sinemurian dolomite layers within 4 distinct stratigraphic units. The 35 sites bearing ichnites are located on the plateau margin. For the first time, morphologic characters studied through descriptive statistic methods with the usual parameters and classical Student and Snédecor tests, allowed us, to divide the whole set of biped traces into 6 ichnospecies. Their definitions are further constrained by multivariate statistical results using Principal Component Analysis (PCA), Factor Analysis of correspondances (FAC) and Discriminant Analysis (DA). All have confirmed the morphologic observations. So that now, the following taxa are identified : Grallator variabilis, G. lescurei, G. sauclierensis, G. minusculus, Eubrontes giganteus, Dilophosauripus williamsi, cf. Moraesichnium, Orníthopus fabrei nov ichnosp. The more immediately visible differences relate to the interdigital II-IV divarication and the digit length ratio. To this panel, we must add Batrachopus deweyi and shapes suggesting Trisauropodichnus and/or Anomoepus. Among all ichnite associations described in the lower Liasic, the New England assemblage presents the most affinities with ours. It shows the ichnotaxa Grallator, Dilophosauripus, Eubrontes, Batrachopus without forgetting Ornithopus fabrei nov. ichnosp. which is close to Ornithopus gallinaceus from the Massachusetts and Connecticut basins. On comparing the present early Jurassic ichnofauna of the Causses with the ones of the Middle and Upper Triassic formations of the eastem border of the Massif Central (France), it appears that tridactyl footprints become more and more numerous and large from Triassic to Early Jurassic. In the Causses, these latest are prevalent but in Quercy (France), Poland, Italy, USA, they are also associated with Omithopoda, Thyreophora and Sauropoda ichnites. Footprint areas considered here were generaly under an arid climate. Animals that passed by were heavy and bulky possible Megalosaur trackmakers, and lighter and slender Coelophysids or Ceratosaurs. For all, these areas were pathways as the orientations of the trackways seem point out. The directions followed by these reptiles were without any important variation during the Hettango-Sinemurian stages. These areas were also used from time to time by Crocodilomorpha and may be tetradactyl (I-IV) bipedal avian Theropods. However, the number of such trackways in sites, sometimes substantial, should not lead us to overestimate the trackmakers populations. These last were probably relatively moderately abondant in this inter-supratidal swamp environment. In the Causses, ichnites are connected with former algo-laminated deposits (Algal mats) which were rapidly hardened by means of calcitisation of cyanobacteria. The result has been a moderate depth of footprints; autopodia disturbing only a few cm of the carbonate substrate. Other fossils have been discovered : invertebrates with thin bivalve and gastropod shells, crustaceans tests and plants. These latter suggest the existence of paleomangroves like environments but also continental vegetation periodically overruning the swamp environment during regression/transgression cycles. At these times, wooded parts of it, could become protecting, feeding, resting and nesting places.

  

The presence at Silveirinha of one of the earliest, ? Late Paleocene or Lowermost Eocene, european representatives of the genus Diplocynodon is based mostly on isolated bones and teeth (often from juveniles). This small-sized form is the only crocodilian so far recognized in this site. The longevity of Diplocynodon in Portugal becomes much extended; the genus survived there until the Middle Miocene at least. A discussion on the possible affinities with other eocene Díplocynodon and especially those from Cubillos-Valdegallina (Zamora, Spain) is presented. On the other hand, differences have been detected in comparison with: Díplocynodon tormis, from the middle Eocene of the Douro basin in Spain, which may belong to another phyletic line; and the aff. Diplocynodon from Dormaal (Belgium) and Le Quesnoy (France), nearly contemporaneous of Silveirinha. The Silveirinha Diplocynodon and many other data strongly suggest moist, subtropical, quite limited in space environments related to an alluvial plain crossed by small, meandering channels. 

L'exploitation des phosphates s'est produite surtout de 1890 à 1914 de Saint-Antonin à Cajarc, sur le Causse de Limogne, dont l'histoire géologique et morphologique peut expliquer les conditions de gisement du minerai, et aussi la découverte des nombreux, variés et beaux fossiles qu'on a extrait des poches en même temps que la phosphorite. Le Causse de Limogne est le nom donné par les géographes au plateau calcaire, faisant partie des Causses du Quercy, et compris entre la vallée du Lot au Nord et celle de "Aveyron au Sud". En fait, le nom de "causse" désigne localement un terroir, un paysage, à sous-sol de calcaire, à sol peu épais, qui s'oppose aux sols argileux des « terreforts » et aux sols légers et profonds des "boulbènes". Chaque communauté agricole distinguait ainsi son causse, par exemple le causse de Caylus, le causse de Limogne ou le causse de Cajarc. C'est par extension que l'appellation Causse de Limogne désigne tout un petit pays. La présence des poches à phosphate déborde un peu vers le Nord la vallée du Lot, et vers l'Est le Causse de Limogne proprement dit (Causse de Villeneuve).   

Abstract not available 

Une hémimandibule et une molaire supérieure recueillies dans le gisement oligocène inférieur d'Escamps (phosphorites du Quercy) fournissent de nouvelles informations sur le genre Pseudorhyncocyon FllHOL, grand insectivore longirostre du Paléogène d'Europe, fossile très mal connu jusqu'ici. Des comparaisons avec les macroscélididés africains, géolabididés nord-américains, et leptictidés euraméricains permettent de rattacher cet amimal aux leptictidés, et de le rapprocher du genre Lepticidium TOBIEN, au sein de la sous-famille européenne nouvelle des pseudorhyncocyoninés. 

Abstract not available 

Deux types de remaniements post mortem me paraissent caractéristiques de l'état de conservation des dents de mammifères fossiles dans les Phosphorites du Quercy :

1) Des destructions localisées d'origine biologique, sous forme de galeries de morphologie très variable creusées dans la dentine et le cément, et impliquant sans doute la participation de différents types de micro-organismes. Ces altérations se sont développées peu de temps après la mort, avant la fossilísation proprement dite et se sont rapidement arrêtées après l'enfouissement dans le sédiment phosphaté.

2) Des perturbations dans les structures de la dentine liées aux variations locales de minéralisation, provoquées par une imprégnation diffuse des zones les moins calcifiées par divers minéraux et probablement surtout de l`apatite. 

La faune de Rongeurs d'Escamps (Lot) bien que relativement pauvre en espèces (dix) s'avère riche d'enseignement pour les Rongeurs de l'Oligocène inférieur d'Europe Occidentale. Cette periode semble caracterisée par une cladogenèse des Théridomyines. A Escamps, un nouveau genre (Patriotheridomys) est décrit ainsi qu'une nouvelle espèce de Theridomys. Avec Oltmamys platyceps, décrit ici plus complètement et désormais bien situé stratigraphiquement, les deux espèces précédentes constituent un ensemble original du Sud de la France. A la même époque, en Angleterre, Allemagne et Espagne, des espèces «régionales» de Théridomyinés se dersifient.  A côté de ces formes qui ne semblent pas franchir la «Grande Coupure» sont représentées deux lignées d'Issiodoromyinés (Elfomys sp et Pseudoltmomys cuvieri), une de Théridomyiné (T. (Blainvillimys) rotundidens) ainsi qu'un Gliridé, Gliravus priscus (que l'on différencie nettement de la deuxième lignée des Gliravus oligocènes : G.  meridionalis -> G. majori). On retrouve ces formes dans les gisements plus récents du niveau de Hoogbutsel où elles sont à peine plus évoluées. Le fait que les degrés évolutifs de ces lignées soient très proches laisse supposer que le laps de temps séparant les niveaux d'Ecamps et Hoogbutsel fut relativement court. 

Pour la première fois un spécimen de lagomorphe a été récolté en Quercy. L'intérêt de ce fossile tient surtout à son âge géologique inattendu, qui recule considérablement la date de première apparition en Europe de cet ordre de mammifère, Ceci nous paraît justifier une nouvelle réflexion sur la « grande coupure» oligocène, 

Abstract not available 

A short review of the genera and species of snakes from the Quercy's phosphorites described by former authors is followed by the study of specimens recently collected. Most of these latter specimens belong to the Aniliidae, Boidae, Colubridae and to the Scolecophidia; the precise systematic position of some of them is not defined yet. The following genera and species are described: Eonilius europae nov. gen. and nov. sp., Platyspondylia lepta nov. gen. and nov. sp., Coluber cadurci nov. sp. and Dunnophis cadurcensis nov.  sp.; a species described by de Rochebrune (Palaeopython filholi) is revised. One of the most important conclusions of this study is that the Colubridae appear as early as the Upper Eocene. The stratigraphic repartition of these snakes shows that the rich Upper Eocene fauna is followed by the very reduced fauna of the Lower Oligocene; then the oligocene «Grande Coupure» corresponds to a very important faunistic renewal. The fauna remains poor and little diversified during the beginning of the Middle Oligocene after which there is a new faunistic explosion.