Palaeotis weigelti, from the Middle Eocene of central Europe, is a flightless, paleognathous bird. It appears to be a member of the ostrich lineage on the basis of trivial derived characters. It is a very primitive ratite, however, and does not possess any of the highly specialized cursorial adaptations that characterize the modern steppe -and savanna- dwelling ostriches. 

The first good skeletal remains of Homogalax protapirinus from the Wasatchian of the Bighorn Basin, Wyoming, indicate that this primitive tapiromorph was more plesiomorphic in many features than primitive equoids including Hyracotherium. Compared to Hyracotherium, Homogalax more closely resembles Phenacodonta (the closest outgroup of Perissodactyla for which postcrania are known) in various details of articular surfaces, muscle attachments, and proportions of the humerus, manus, and pes.Among known taxa, Homogalax most nearly approximates the plesiomorphic postcranial skeletal anatomy of Perissodactyla. 

The earliest cetaceans are found in the early Eocene of Indo-Pakistan. By the late middle to late Eocene, the group colonized most oceans of the planet. This late Eocene worldwide distribution clearly indicates that their dispersal took place during the middle Eocene (Lutetian). We report here the first discovery of a protocetid fossil from middle Eocene deposits of Senegal (West Africa). The Lutetian cetacean specimen from Senegal is a partial left innominate. Its overall form and proportions, particularly the well-formed lunate surface with a deep and narrow acetabular notch, and the complete absence of pachyostosis and osteosclerosis, mark it as a probable middle Eocene protocetid cetacean. Its size corresponds to the newly described Togocetus traversei from the Lutetian deposits of Togo. However, no innominate is known for the Togolese protocetid, which precludes any direct comparison between the two West African sites. The Senegalese innominate documents a new early occurrence of this marine group in West Africa and supports an early dispersal of these aquatic mammals by the middle Eocene.
  

The principles and practices employed in establishment and recognition of South American land mammal ages are reviewed along with previous and present concepts of distinguishing time, rock, and faunal units. Previous chronological arrangements of South American Tertiary land mammal faunas are appraised on the basis of recent geological and paleontological data. Twelve South American Tertiary land mammal ages are here recognized [from oldest to youngest, Riochican (middle to late Paleocene); Casamayoran (early Eocene); Mustersan (middle Eocene); Divisaderan (late Eocene); Deseadan (early [to middle?] Oligocene); Colhuehuapian (late Oligocene); Santacrucian (early Miocene); Friasan (middle Miocene); Chasicoan (late Miocene); Huayquerian (latest Miocene); Montehermosan (early to middle Pliocene); and Chapadmalalan (late Pliocene)]. As all except the Friasian were originally defined on the basis of Argentine faunas, these are discussed first and at length, and each is reviewed with discussion of type locality, stratigraphy, type fauna, and faunal correlations. Non-Argentine faunas are then discussed country by country in alphabetical order.

     A review is given of radioisotope dates obtained on volcanic rocks (i.e., basalts, tuffs) associated with mammalbearing beds in Argentina. Based on these age determinations and on correlation of the late Tertiary land mammals involved in the interchange between North and South America, a chronology of South American land mammal ages correlated with North American land mammal ages and European marine stages is proposed.

It is concluded that South America was an island continent through most of the Tertiary Period (ca 65 to about 3 Ma). As a result, the land mammal fauna of South America developed in isolation and was dominated by autochthonous endemic groups. Toward the end of the Tertiary (i.e., middle Miocene) a unique faunal balance had been achieved by the descendants of the ancient inhabitants (notoungulates, litopterns, condylarths, astrapotheres, edentates, marsupials) and of later (late Eocene) waif immigrants (caviomorph rodents, platyrrhine primates). A prominent feature of this mammal fauna was the combination of carnivorous and omnivorous marsupials with native placental herbivorous ungulates, subungulates, and edentates.

Sometime during the late Miocene, a limited but important interchange of mammalian taxa between North and South America took place. Procyonids (raccoons and their allies), a group of North American origin, first appear in South America in strata of Huayquerian Age, while members of the extinct South American ground sloth families Megalonychidae and Mylodontidae first appear in North America in early Hemphillian time. These groups dispersed along island arcs before the appearance of the Panamanian land bridge in the Pliocene (ca 3.0 Ma). Cricetine rodents, a group of North American origin, are first known in South America in strata of Montehermosan Age. The known taxa are too advanced and diversified to be considered the first of this group to invade South America. lt is believed by some workers that these rodents arrived before the Montehermosan, possibly in the late Miocene or earlier, by waif dispersal from North America.

The isolation of South America ended with the appearance of the Panamanian land bridge, which provided a direct, dry land connection between the two Americas. Across this portal an extensive interchange of terrestrial faunas occurred, and the fossil record documents an intermingling of these long-separated land mammals faunas.

      The beginning of this interchange by land route in South America is marked by the appearance of mammals which evolved from North American emigrants in the Chapadmalal Formation of Argentina. These include a mustelid (Conepatus), a tayassuid (Argyrohyus), and four genera (Akodon, Dankomys, Graomys, Reithrodon) of cricetine rodents. The appearance of this contingent of northern animals favors the existence of the Panamanian land bridge by this time. Likewise, a large number of terrestrial vertebrates of South American origin appear in North America in beds of late Blancan Age date around 2.7 Ma. Among the mammals are Neochoerus, Erethizon, Glyptotherium, Glossotherium, Kraglievichia, and Dasypus. 

Based on fossil discoveries and phylogenetic studies, an Eocene Asian origin for hystricognathous rodents and anthropoid primates has gained strong support in recent years. The two groups then invaded both Africa and South America, which promoted their evolutionary success. However, the fossil record has so far failed to constrain the nature and precise timing of these pivotal dispersal events. In Africa, given the apparent absence of hystricognaths and anthropoids in early to early middle Eocene localities, it is suggested that these mammal groups dispersed from Asia to Africa sometime during the middle Eocene. In this paper, we report the discovery of several isolated teeth of a rodent from a new vertebrate locality situated in central Tunisia (Djebel el Kébar, KEB-1), dating from the late middle Eocene (Bartonian, ~39.5 Myr). These fossils document a diminutive new species of Protophiomys (P. tunisiensis nov. sp.), a basal genus of hystricognathous rodents which is well known from several North African mammalian-bearing localities of the end of the Eocene. The teeth of P. tunisiensis display a suite of anatomical details comparable with those observed in the other species of the genus, but with a lesser degree of development. Such an apparent primitive evolutionary stage is corroborated by the greater antiquity of this Tunisian species. P. tunisiensis nov. sp. is so far the most ancient representative of hystricognaths in Africa. However, it can be expected that hystricognaths were already present on that landmass given the new data on early caviomorphs recently reported from South America (at ~41 Myr). The arrival of hystricognaths in Africa from South Asia certainly predates the depositional period of the Kébar sediments, but perhaps not by much time. 

Valverde's cenogram method is used to analyse mammalian communities from the late Eocene to late Oligocene of southern France, mainly from the "Phosphorites du Quercy". Cenogram analysis involves plotting the size of each component species in a fauna on a semilog diagram in rank order, permitting fossil faunas to be compared with Recent ones. The configurations of Recent communities serve as models for establishing the general environmental characteristics of fossil mammalian faunas. This method of analysis applied to faunal sequence can reveal major and sudden ecological perturbations. The paleobiogeographical event (i.e. the mammalian immigration wave) at the Eocene-Oligocene Boundary in western Europe, known as the «Grande Coupure", is here shown to represent a drastic and sudden ecological change: late Eocene tropical environments in Europe deteriorated rapidly turning to subdesert or desert environments al the beginning of the Oligoccne. 

The Late Campanian Cerro del Pueblo Formation, located in southeastern Coahuila, Mexico, has produced a diverse array of vertebrate fossils. However, pterosaur remains from this unit are notably scarce. In this study, we describe new pterosaur material from the formation. The specimens include a fragmentary vertebra identified as belonging to an indeterminate, but derived pterodactyloid, along with the distal condyle of a left metacarpal, referable to an azhdarchoid pterosaur, and a left manus print. While these specimens provide additional evidence of pterosaur presence in the region during the Late Cretaceous, their fragmentary nature limits precise taxonomic and ichnotaxonomic identification. Nevertheless, they highlight the potential for future discoveries that could refine our understanding of the diversity and distribution of pterosaurs in Mexico.
  

Designated the type-locality of a late Eocene paleomammal zone, Robiac has recently been the object of important excavations. The first results of the new collecting, as  well as a revision of the material in old collections, are given in this work.
Two stratigraphic section, cutting through the two sites presently distinguished (Robiac-Nord and Robiac-Sud) reveal the lithologic variation at the base of the Fons Limestone and the localization of three fossiliferous beds at Robiac-Sud.
The molluscan fauna and the flora (charophytes), which have already been described, as well as that of the lower vertebrates, have been listed.
A list of 46 mammalian species (only 16 species were known previous to 1964) has been established. The micro-mammals, nearly all new in this fauna (marsupials, insectivores, bats, rodents, primates, and some smallsized artiodactyls), Were obtained only after screen-washing of the matrix; about 4 tons of sediment were thus treated.
The artiodactyls have been the most extensively analyzed; 6 genera, of which one is new, have been recognized. The latter is described as Robiacina minum n.g., n.sp., and represents a very small artiodactyl of the family Anoplotheriidae. The taxonomie status of certain species formerly described has been clarified by the designation of lectotypes (Cebochoerus robiucensis, Catodonerium robiacense, Xiphodon castrense).
The paleontologic corrélations at present possible between the late Eocene faunas have allowed the relative positions of te different French localities of this age to be established; the Guépelle locality, it seems, could define in the future a new paleomammal zone.
  

Anthracotheres from the Pondaung Formation, Myanmar, are considered as one of the most primitive artiodactyl groups and they represent the oldest known record in the world. Thus, the understanding of this group has numerous implications for evolutionary biology and biochronological correlations. However, the systematlcs of these mammals has been interpreted in different ways, and the main debate focuses on the number of taxa represented in the Pondaung Formation. The revised taxonomy proposed here is mainly based on the relative development of the upper molar W-shaped ectoloph, system of crests and stylar cusps, and on body size. On the basis of these characters, they are classified into four genera including six different species. Two well-known genera, Anthracotherium and Anthracokeryx, are validated and more precisely diagnosed. Anthracokeryx possesses a better developed W-shaped ectoloph, system of crests and stylar cusps than Anthracotherium, which displays notable differences with the more derived representatives of this genus. Both of these Pondaung genera show evidence for sexual dimorphism. However, the incompleteness of fossil material fueled a debate concerning the status of two additional Pondaung anthracotheres, Siamotherium and Anthracohyus. The latter genus is of uncertain affinities, but it has been considered as a hippopotamid ancestor. Despite new material attributed to these two forms, additional discoveries are still required to establish their taxonomic status. The hypothesis that Southeast Asia was the centre of origin of Anthracotheriidae is supported by the retention of numerous primitive dental characters in these taxa and by the antiquity of the Pondaung Formation, to which an age of 37 My is now generally accepted. 

The mammalian fauna (represented only by isolated teeth) from the early Cretaceous of Morocco includes a number of non-'therian' specimens, characterized by the antero-posterior alignement of the main molar cusps. This assemblage is very heterogenous, including forms (among them Gobiconodon palaios sp. nov.) that can be related to Laurasian triconodonts and several forms so far known only in this part of Gondwana (among them Kryptotherium polysphenos gen. et sp. nov.). The latter, in particular, exemplifies the diversity of the mammalian dental morphology in the Mesozoic, often largely underestimated. In the last part of this paper, the 'therian' affinity of the 'amphilestids' is discussed, on the basis of the arrangement of molar cusps, the interlocking mechanism and the occlusal pattem. 

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.

  

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. 

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 wear facets of primitive rodents can be homologized with those of primitive primates and ungulates. As in primates, the jaw movement was ectental, with an increased anterior component in the lingual phase (phase ll). The buccal phase (phase I) in rodents approaches the horizontal and it tends to be reduced in importance in comparison with the lingual phase. ln more advanced rodents the efficiency of grinding is increased by the development of additional cutting edges of enamel (e.g. enlargement of hypocone, development of mesoloph and lingual sinus). The buccal phase movement becomes lined up with the lingual phase movement to form a single oblique chewing stroke,resulting in planation of the crown. As the stroke becomes more longitudinal (propalinal) the enamel edges become more transverse. In Muridae propalinal chewing evolved before the loss of cusps, facets were reorientated and additional cusps developed. 

We report the discovery of amniotic eggshells and theropod teeth from the Late Cretaccous  period in Morocco.The megaloolithid family represents the only known dinosaur egg remains in the north part of Africa and attests indirectly to the occurrence of sauropod dinosaurs (titanosaurids) in the Maastrichtian of Africa.

  

A new middle Miocene hipposiderid bat is described from a limestone deposit on Riversleigh Station in north-western Queensland. Hipposideros (Brachipposideros) nooraleebus n. sp. is the first record of this subgenus from anywhere in the world outside of France. The palaeoecological setting of the fossil bats appears to have been a relatively quiet, sunny lime-enriched tropical pool that contained tortoises, crocodiles and fish. It is possible that the bats were washed into the pool from an adjacent cave.
The Riversleigh bat most closely resembles the French Burdigalian (early middle Miocene) bat H. (B.) aguilari. It is also possible that it may have been closely related to the original Australian hipposiderid stock that ultimately gave rise to the endemic monotÿpic Rhinonycteris aurantius. The disjunct distribution of species of H. (Brachipposideros) suggests that representatives of this subgenus will be found in at least tropical southern Asia. 

In recent years, the techniques of chemical preparing have permitted a rich paleontologic material to be obtained from the phosporitic sediment of Bouzigues (Hérault, France). The fauna of this locality is comprised of quite varied microvertebrates, amphibians, reptiles, birds, mammals. Twenty five species of the latter, belonging to seven orders, are today known from the site. Among them, the numerous rodents have allowed L. Thaler to chronologically situate this fauna in the Zone of Laugnac (<< late Aquitanian ›> of some authors).
The chiropterans are, with the rodents, the best represented of the locality's mammals. Three families comprise the bat fauna, with nearly complete dominance by one of them (Hippoxideridae) over the two others (Megadermatidae and Vespertílionidae)
Six forms are described, of which three are new species and one a new sub-genus.
Megaderma braillomi n. sp., an animal of rather large size, shows like the Miocene megaderms several evolved dental characters, translating the adaptation of these animals to a partially carnivorous regime. The Bouzigues species seems, however, to represent a particular lineage.
Hipposideros (Brachipposideros n. subgen.) dechaseauxi n. sp. and Hípposideros (Brachipposideros) cf. collongenris Depéret, small sized forms, belong to a group rather well represented in the late Oligocene and early Miocene of Europe, and not distinguished until now within the genus Hipposideros.
Hipposideros (Pseudorhinolophus) bouziguensis n. sp., is the most abundant mammal in the locality and, occuring at the Oligocene-Miocene limit, the last representative known of the subgenus Pseudorhínolophus, common in Europe from the middle Eocene.
However, beyond Neogene and Quaternary times, certain among the numerous living species of Hipposideros are close to Pseudorhinolophus and others to Brachipposíderos. 'This fact would in the future justify a global revision of the genus, on the basis of comparative anatomy of the squeleton and of the teeth.
The bat fauna of Bouzigues is completed by two small Vespertilionidae, rare forms, Myoris sp. I and sp. II.
  

Rodents first appear in the latest Paleocene or earliest Eocene as very fragmentary specimens (Family Paramyidae) known largely from a single locality. After this sparse beginning, rodents are usually abundant in the North American record if proper recovery methods are used. Utilization of rodents for biostratigraphic purposes depends on 1/ extinction, and 2/ replacement by evolution of endemic groups and/or incursions of Old World rodents, and rarely and late by South American kinds. These incursions are separated by relatively long periods of isolation in the Paleogene, but more episodic in the Neogene. At least 10 rodent zones can be characterized by major distinctions, and these zones can be amplified into as many as 16 with little trouble. In general, rodent genera permit as refined a zonation as do genera of large mammals. Distinction at a specific level has not been attempted herein except in the Blancan and Post-Blancan. 

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. 

A comparative bone histological study of the three known genera of the endemic European ornithopod dinosaur family, Rhabdodontidae, is presented here in an ontogenetic context. Investigated specimens were assigned to different ontogenetic stages based exclusively on the histological indicators of osteologic maturation during diametrical bone growth; an entirely size-independent method as opposed to most previous studies. Qualitative comparison of bone histology of corresponding ontogenetic stages and elements among the three valid rhabdodontid genera, Mochlodon, Zalmoxes, and Rhabdodon, revealed some consistent patterns. Genus specific histological differences within Rhabdodontidae are most expressed between Rhabdodon and the Mochlodon-Zalmoxes clade. These indicate a prolonged phase of fast growth and a less constrained cyclicity in the growth dynamics of Rhabdodon, as opposed to the slower and more regulated growth strategy reflected in the bones of Mochlodon and Zalmoxes. These genus specific differences are consistent with the phylogenetic interrelation of the genera and are most probably related to the pronounced differences in body size. However, when compared to other ornithopods, most detected histological features in rhabdodontids do not seem to reliably reflect either phylogenetic relations or body size. A notable common feature of all rhabdodontid genera irrespective of body size is the ontogenetically early onset of cyclical growth and secondary remodelling; a pattern that more resembles the condition found in derived ornithopods than that described in more basal taxa which are closer relatives of rhabdodontids. The recognition of taxon-specific histological patterns as well as patterns indicative of ecological and thereby functional traits clearly requires more accurate, preferably quantitative evaluations.