Two somewhat “odd” taxa of theridomyid rodents, one formerly known (Bernardia marandati Vianey-Liaud, 1991) and the other new (Idicia vidalenci gen. et sp. nov.) are discussed from a taxonomical and taphonomical perspectives. These two rodents were found at Lavergne, a late middle Eocene (MP16) “phosphatière” from the Quercy (Southwest France). The genus Bernardia, being preoccupied by a scale insect (Bernardia Ashmead, 1881), is here renamed Burgia. We benefit from this nomenclatural change to describe additional new dental specimens of this patriotheridomyine species, including a previously undescribed locus (P4). The other theridomyid from Lavergne, Idicia vidalenci gen. et sp. nov., so far documented by a mandible preserving two teeth (m2-m3) is a new taxon of peculiar occlusal morphology, and whose subfamilial affinities remain unknown. These two peculiar theridomyids recorded at Lavergne are found nowhere else, whether in coeval localities in Quercy or elsewhere in Western Europe. We discuss the possible causes of their unique presence at Lavergne.
  

HGL50 is a latest Early-early Middle Eocene vertebrate-bearing locality located in Western Algeria. It has produced the richest and most diverse fauna of amphibians and squamate reptiles reported from the Palaeogene of Africa. Moreover, it is one of the rare faunas including amphibians and squamates known from the period of isolation of Africa. The assemblage comprises 17 to 20 taxa (one gymnophionan, one probable caudate, three to six anurans, seven ‘lizards’, and five snakes). Two new taxa were recovered: the anuran Rocekophryne ornata gen. et sp. nov. and the snake Afrotortrix draaensis gen. et sp. nov. The locality has also yielded the first confirmed anilioid snake, the first Palaeogene gymnophionan, and probably the first caudate from the Palaeogene (and possibly from the Tertiary) of Africa. The presence of a caudate at that time in Africa would be of particular interest; unfortunately, the available material does not permit a definitive identification. The fauna comprises Gondwanan and more specifically West Gondwanan vicariants, probably autochthonous groups and a Eurasian immigrant (assuming that the identification of the caudate is accurate). The fauna from HGL50 is clearly distinguished from the few other Eocene assemblages of Africa. However, if this results largely from differences in geological ages, geographic positions of the localities and mainly differences in environments took a part in the composition of the faunas. 

Résumé :
L’étude des rongeurs Theridomorpha permet de suivre le déroulement d’une radiation adaptative pendant toute sa durée (Eocène moyen-Oligocène terminal), sur un territoire restreint à l’extrémité ouest de l’Europe Occidentale. Dans ce papier, la phylogénie de ce groupe est établie à partir d’une analyse cladistique reposant sur l’examen de 315 caractères (310 dentaires). Le groupe d’intérêt comprend 110 des 132 espèces (24 genres) de Theridomyoidea et deux genres encore inclus jusqu’ici dans les Reithroparamyinae qui rejoignent les Theridomorpha. Les groupes externes comprennent des Glires basaux, Cocomys, Tanquammys et 16 Ischyromyiformes. Un cadre phylogénétique robuste est produit, qui permet de clarifier la systématique des Theridomorpha. La position des Remyoidea (nov. sup.fam.) au sein des Ischyromyiformes, extérieure aux Theridomorpha, est confortée. Les Protadelomys et Tardenomys sont à la base des Theridomyoidea, avant la séparation en deux clades correspondant aux familles Pseudosciuridae et Theridomyidae. Les sous-familles sont consolidées : Pseudosciurinae et Sciuroidinae pour les Pseudosciuridae ; Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, auxquelles s’ajoute au moins une nouvelle sous-famille (Patriotheridomyinae), pour les Theridomyidae. La topologie des chrono-espèces (sensu Simpson), traitées antérieurement comme lignées évolutives, apparaît dans la plupart des cas sous forme de clades successifs dans lesquels les espèces sont le plus souvent arrangées de manière pectinée, émergeant dans l’ordre stratigraphique. L’analyse des caractères aux principaux nœuds permet de consolider les caractères diagnostiques des taxons et les tendances évolutives, ainsi que de discuter des divers parallélismes et convergences dans l’évolution des structures et patrons dentaires (e.g., émail des incisives unisérié chez les Issiodoromyinae et les Patriotheridomyinae, ou pseudo-multisérié chez les Blainvillimys les plus hypsodontes, les Protechimys et Archaeomys ; patrons dentaires téniodontes ; allongement des dents déciduales chez les Patriotheridomyinae, Issiodoromyinae et Theridomyidae ; sélénodontie ou lophodontie). Les dynamiques évolutives traduites par les changements morphologiques sont mises en relation avec les variations environnementales. Enfin, les implications biochronologiques de l’évolution des Theridomyoidea sont discutées.
Abstract:
The adaptive radiation of the rodents Theridomorpha occurred during a limited time window (middle Eocene to late Oligocene), on an area restricted to Western Europe. In this paper, the phylogeny of this group is established via a cladistic assessment of 315 morphological characters (310 dental). The group of interest encompasses 110 upon 132 species (24 genera) of Theridomyoidea, and two genera formerly included within the Reithroparamyinae, and which are included here within the Theridomorpha. The outgroups include basal Glires, Cocomys, Tanquammys and 16 Ischyromyiformes. A robust phylogenetic frame is produced, which allows clarifying the systematics of the Theridomorpha. Within the Ischyromyiformes, the Remyoidea (nov. supfam.) are set apart from the Theridomorpha. Protadelomys and Tardenomys represent the earliest offshoots of the Theridomyoidea, before the dichotomy between Pseudosciuridae and Theridomyidae. It supports the former subfamilies Pseudosciurinae and Sciuroidinae within the Pseudosciuridae; and for the Theridomyidae: the Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, with at least one new subfamily (Patriotheridomyinae). The topologies of the chronospecies (sensu Simpson), formerly considered as evolutionary lineages, appear in most cases as successive clades, in which the species are generally pectinately arranged and emerging in the stratigraphic order. The analysis of characters supporting the main nodes allow consolidating the diagnosic characters of the taxa and their evolutionary trends, as well as discussing the various cases of parallelism and convergence in the evolution of structures and dental patterns (e.g., uniserial incisor enamel for Issiodoromyinae and Patriotheridomyinae, or pseudo-multiserial for the most hypsodont Blainvillimys, Protechimys and Archaeomys; taeniodont dental patterns; lengthening of deciduous premolars for Patriotheridomyinae, Issiodoromyinae and Theridomyidae; selenodonty or lophodonty).
Evolutionary dynamics are analysed with respect to environmental changes. Finally, biochronological implications of the evolution of Theridomyoidea are discussed.
  

Abstract: A very tiny cuckoo, Chambicuculus pusillus, was recently described after a few fragments of tarsometatarsi from the late Early/early Middle Eocene of Djebel Chambi, Tunisia. New remains, notably a coracoid, confirm the attribution of this genus to the recent family Cuculidae. This coracoid shows a very elongate and strap-like processus procoracoideus. This morphological feature is otherwise only known in the family Cuculidae. The characteristics of the coracoid and tarsometatarsi show that Chambicuculus is morphologically more advanced over the other stem cuculids described in Europe and North America. Chambicuculus is the oldest Cuculidae known so far. 

The Oligocene deposits of the Ulantatal area in Inner Mongolia (China) contain among the richest mammalian faunas from Asia. To date, only some parts of the rodent faunas have been described. Here, we propose to review the rodent faunal lists for each site, including the description of a few new rodent specimens. We describe three additional rodent species: the Cylindrodontidae Anomoemys lohiculus, the Eomyidae Asianeomys sp., and the Dipodidae Litodonomys huangheensis. This study allows us to constrain the stratigraphic range of Anomoemys lohiculus, which ranged from the late Early Oligocene to the early Late Oligocene in this area. Asianeomys sp. and Litodonomys huangheensis are dated from the latest Oligocene. These Oligocene deposits consist now of more than 70 species of mammals if we include the fauna from Kekeamu. This latter corresponds to the basal part of the Ulantatal Formation and could be dated biochronologically from the earliest Oligocene. When compared to the faunas from the Valley of Lakes in Central Mongolia, the Ulantatal faunas present a great majority of rodents, and this difference can be partly explained by sampling and description biases regarding macro-mammals. This study also shows that variations existed between Inner and Central Mongolia, especially regarding the composition of the rodent paleocommunities. However, the assessment of their evolutionary history in this part of Asia with respect to the important climate and environment changes, require further precisions and more material than current data allow. 

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. 

This paper proposes a systematic revision of the Oligocene Mongolian Ctenodactylidae, on the basis of abundant material obtained by screen/washing operations in stratified localities of the Ulantatal area (Inner Mongolia) (UTL1, 2, 3, 4, 5, 7, 6 & 8). A Chinese-German team has collected several thousands of isolated rodent teeth, and a number of fragmentary jaws. A new genus is identified (Alashania nov. gen. tengkoliensis nov. sp.), and eight former species are reevaluated, Karakoromys decessus, Tataromys sigmodon, T. minor, T. plicidens, Yindirtemys ulantatalensis, Y. bohlini, Y. deflexus, with several synonymies. A new Yindirtemys species is described: Y. shevyrevae nov. sp. and another one close to that: Y. aff. shevyrevae nov. sp. Four new species, which are rare in the localities, remain in open nomenclature because they are not well-represented. Yindirtemys differs from the other genera by the permanence of crescentic structures, while the other genera show a general reduction of the trigonoid area (= anterior valley). We define a range of size variation for each well documented population. Although the dental morphology shows a wide range of variation, given that transitional morphologies occur in a single locality, it is possible to provide a clear definition for most species. We show that dental patterns of the different genera can be derived from the pattern of Karakoromys. As a number of Tataromyinae have been determined in several localities from China, Kazakhstan and Mongolia, usually on the basis of scarce material, or surface collections, the present study would be used to re-evaluate their attribution inasmuch as the taxa are now placed in the Oligocene stratigraphy. The diversity of sizes and forms reflects the adaptive radiation of the family during the Oligocene, within a forested environment where the vegetation was probably abundant. 

Eosimiid and amphipithecid primates document a long and significant history of primate evolution throughout the Eocene in Southeast Asia. Despite the absence of a comprehensive post-Eocene fossil record, it was generally hypothesized that both families left no descendant in Asia. Recently, two new small-bodied taxa, Bugtipithecus and Phileosimias, have been recovered in early Oligocene coastal deposits from the Bugti Hills (Balochistan, central Pakistan) and referred to the families Amphipithecidae and Eosimiidae, respectively, on the basis of dental fossil remains. In this paper, we provide more exhaustive description, comparison, and discussion of these taxa. As for tarsiid and sivaladapid primates, the persistence of eosimiids and amphipithecids into the Oligocene clearly demonstrates that low latitudes of South Asia provided a continuous access to tropical refugia during the climatic deterioration characterizing the late Eocene-early Oligocene interval, which was seemingly lethal for primate communities elsewhere across the Holarctic continents. As a contribution to the ongoing phylogenetic debates regarding the position of eosimiids and amphipithecids on the primate family tree, we have performed a cladistic analysis in a high-level primate systematic context in order to assess the position and the role of these new taxa in that phylogenetic issue. Our results support the view according to which eosimiids and amphipithecids (and by extension Phileosimias and Bugtipithecus, respectively) are stem anthropoids. These fossils from Pakistan document an unsuspected Oligocene phase of the evolutionary history of anthropoid primates in southern Asia, which clearly enhances the extent of the anthropoid radiation in this province during the Paleogene. Several phylogenetic and paleobiogeographic aspects are discussed, notably the intra- and inter-relationships between Paleogene Asian and Afro-Arabian anthropoids, and the resulting potential dispersal models between both land-masses during the Paleogene.