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The rodent associations from the late Oligocene deposits of Ugljevik and Paragovo in the Pannonian basin are described. Pannoniamys paragovensis, a new genus and species of Spalacidae, is defined. The published data from a third late Oligocene locality in the area (Banovići) is included in the discussion of the changes in community structure through the time-interval studied. Although the composition of the rodent faunas studied differs, the dominating cricetid genus in all three associations is Deperetomys, a genus that appears in western Europe during the late middle Miocene. While the late Oligocene rodent record of central and southwestern Europe is characterised by endemic development, the regime in the Balkans seems to have been one of multiple immigrations and replacements. The late Oligocene age of the rodent fauna from Ugljevik estimated at about 26 Ma, provides a minimum age for the start of rifting in the Pannonian basin, some 6 Ma earlier than previously documented.

Two species of the family Eomyidae are identified in the Early Miocene localities of the Araia d’Alcora outcrop (Ribesalbes-Alcora Basin, Iberian Peninsula): Ligerimys florancei and Ligerimys ellipticus. The first is rarer than the second, which is one of the most abundant mammals in the Ribesalbes-Alcora Basin assemblages. Due to its abundance, we are able to describe its variability in dental morphology, showing characteristics never previously observed, including the presence of a mesoloph or other features previously described only in ancient assemblages of this species, such as the presence of the anteroloph, which appears in younger assemblages in the Araia sequence. Furthermore, based on the eomyids, we divide the record of the Campisano Ravine section into two long local biozones, depending on the species present. In addition, each local biozone is divided into two smaller sub-biozones, depending on the abundance of each species. We retrospectively compare and correlate the assemblages studied here with other Ligerimys assemblages from the other basins in the Iberian Peninsula. We classify these sites based on the abundance and species of the genus Ligerimys. Additionally, we discuss the palaeoecological preferences of these species, RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA , V. 127 N. 3 (2021)

In Asia, the first find of an eomyid rodent was reported almost one century after the first studies of the family Eomyidae in North America and Europe. Since then, eomyid rodents have been increasingly found in Asia particularly over the past two decades. Here, we review the Asian record of this family at the genus level. Currently, 22 species within 14 genera were reported from Asia, including seven endemic genera and rare materials of apeomyine eomyids. Eomyids emphasize the palaeogeographic importance of Asia in considering intercontinental dispersal events of small mammals. With newly compiled data for Asian eomyids, we also compare genus-level diversity trends through time among North America, Europe, and Asia. Despite data standardizations limited with respect to potential biases in the fossil record, we found that the Asian eomyid diversity closely follows ecological shifts induced by climate changes. In general, Asian eomyid genera disappeared earlier than their European counterparts. We suggest that this pattern is not dictated by differences in the quality of the fossil record and is related to the expansion of drier habitats over large areas of Asia. Y.K. received financialsupport from the Japan Society for the Promotion of Science,Tokyo, Japan (JSPS, KAKENHI Grant Number JP18K13650,Grant-in-Aid for Early-Career Scientists) and also from theNational Museum of Nature and Science as part of a researchproject called “Chemical Stratigraphy and Dating as a Clue for Understanding the History of the Earth and Life”. I.C.-V.was financially supported by the Spanish Ministerio deEconomía, Industria y Competitividad, the Agencia Estatal deInvestigación and the European Regional Development Fund of the European Union (projects CGL2016-76431-P, AEI/FEDER EU, CGL2017-82654-P MINECO/FEDER EU; andresearch contract RYC-2013-12470), and the Generalitat deCatalunya (CERCA Programme). I.C.-V. is a member of theconsolidated research group 2017 SGR 116 of the Generalitatde Catalunya. O.M.’s research is supported by a grant of theSwiss National Science Foundation (N° 200021-162359).D.C.K acknowledges the Deutsche Forschungsgemeinschaft(DFG, Bonn, Germany) for various grants to study mammalianenamel microstructure. T.M. was financially supported by The Royal Swedish Academy of Sciences (KVA, Stockholm,Sweden) and by JSPS, Tokyo, Japan.

A new genus and species of sciuravid rodent, Perasciuravus mcintoshi, is named from the late Bridgerian (early Eocene) of the Washakie Formation, southcentral Wyoming. The most distinguishing characters of the species (and genus) are that it retains the primitive condition of the zygomasseteric structure for rodents, characteristic of sciuravids, but has a more specialized dental morphology of the cheek teeth (complete ectolophids and hypolophids on the lower molars; complete metalophs and protolophs on the upper molars) typical of the later-occurring family of geomyoid rodents, the Eomyidae. Perasciuravus is viewed as morphologically transitional between the Sciuravidae and the Eomyidae. Its occurrence also overlaps the temporal range of the Sciuravidae (Wasatchian [early Eocene] to Duchesnean [early-late Eocene]) and predates the first occurrence of the Eomyidae (Uintan [middle Eocene]).

The John Day Formation of Oregon is one of the richest and best studied assemblages in North America. Including seven members and spanning about 20 million years, there are over 150 vertebrate species known from the John Day Formation. The rodent faunas of John Day have not been as well studied as larger mammals, with many families having received little attention in the last hundred years. Here, twenty one species of rodents are described, based on new discoveries and previously unpublished specimens from the John Day Formation. The new material includes four new genera and species; the eutypomyid Allotypomys pictus, the anchitheriomyine castorid Microtheriomys brevirhinus, the eomyid Proapeomys condoni, the heteromyid Bursagnathus aterosseus; and six new species: the sciurine sciurid Miosciurus covensis, the eomyids Apeomys whistleri and Neoadjidaumo arctozophus, the heteromyids Proheteromys latidens and Trogomys oregonensis, and the sicistine dipodid Plesiosminthus fremdi. The problematical eo...

Three species of Yoderimyinae (Eomyidae: Rodentia) are recognized from the lower part of the White River Formation (early to medial Chadronian) in the Flagstaff Rim area, Wyoming. The new material allows an improved diagnosis for the subfamily. The enamel microstructure of Yoderimyinae supports its inclusion in the Eomyidae.A new genus, Zemiodontomys, is established for Yoderimys burkei Black, and new material, including upper dentition, is referred to this species. This genus differs from Yoderimys in having higher crowned and more lophodont teeth and in lacking P3. A second new genus, Litoyoderimys, is established for Yoderimys lustrorum Wood, and a new species, L. auogoleus, is referred to the genus. This genus has lower crowned, more cuspate teeth than Yoderimys.Through early and medial Chadronian time, evolution in yoderimyines includes the following morphologic transformations: increase in size; increase in crown height and lophodonty of cheek teeth; reduction of P3 (from double-rooted, to single-rooted, to absent); increase in relative size of P4 and p4; and increased longitudinal torsion of the mandible.

A partial skeleton of a young adult Eomyodon volkeri from the late Oligocene of Enspel (MP 28) represents the first of this genus, which was previously known only from isolated teeth at this locality. The specimen was split in two slabs upon discovery, and both parts were transferred to an artificial plastic matrix. Soft parts are preserved in the partial skeleton which comprises most of the skull with both mandibles, an incomplete vertebral column with parts of the ribcage, the right scapula with a clavicle fragment, almost the entire right forelimb (hand and left radius and ulna), parts of the pelvis and the left hind limb without the foot. It shows a generalised rodent ‘bauplan’; body mass is estimated to be about 10 g based on femur length. The lengths and proportions of the phalanges indicate a terrestrial lifestyle, and the preserved soft parts do not indicate any adaptations for gliding.

Two species of the eomyid rodent Paradjidaumo are recognized from the Chadronian (latest Eocene) White River Formation in the Flagstaff Rim area of Wyoming: P. hansonorum from early Chadronian levels and P. nanus, new species, from higher levels representing the middle Chadronian.

The material of Eomyidae from three localities (Morteral 1, Morteral 20A and Morteral 22) of the Morteral section in the Magro Basin, eastern Spain, is described. These localities contain remains of Ligerimys and Eomyops. Morteral 1 is situated in the lowest part of the section and contains Ligerimys ellipticus, whereas Morteral 20A and Morteral 22 are situated in the middle part of the section and contain, among other rodent species, Eomyops noeliae. The youngest localities in the Morteral section (Morteral 41 and 44) record Megacricetodon collongensis, first representative of Megacricetodon in the Middle Miocene (MN5). The locality Morteral 20A contains Megacricetodon primitivus; Morteral 1 and Morteral 22 contain a form of Megacricetodon different from both M. primitivus and M. collongensis, therefore, these three localities are of lower Aragonian age (MN4). In the Aragonian type area, L. ellipticus is rare in zone B (lower part of MN4) and frequent in zone C (upper part of MN4). The first record of Eomyops in the Aragonian type area occurs in MN7/8 and in MN5 in Central Europe. The turnover of eomyid faunas in MN4 localities of the Morteral section clearly confirms the hypothesis of Engesser (1999) that Eomyops may have appeared earlier than supposed so far (MN5).

The White River Formation at Flagstaff Rim in central Wyoming is a key sequence for understanding the biochronology and chronostratigraphy of the Chadronian North American Land Mammal Age. The lower part of this section represents early Chadronian time, an interval whose fauna has not been well known. From these early Chadronian levels 15 species of rodents are discussed and/or described. Of these, three are new species, all belonging to the Eomyidae: Namatomys erythrus, Metanoiamys paradoxus, Cristadjidaumo skinneri. These rodent assemblages add substantially to our knowledge of early Chadronian faunas, and show successional changes in the rodent taxa from the earliest Chadronian through middle Chadronian.

The study of extinct Eomyid rodents represents an important segment of Burkart Engesser’s scientific work. To pay tribute to Burkhard’s work, this paper presents remains of Eomyops Engesser, 1979 from the German Jungere Serie localities Kleineisenbach, Giggenhausen, Marktl, Hammerschmiede and Hillenloh. Two Eomyops species are recorded, i.e. E. oppligeri Engesser, 1990 and E. catalaunicus (Hartenberger, 1966). A third form, only found at the locality Marktl, is retained in open nomenclature. In spite of the richness of the studied material, the time gap separating the individual localities does not allow to assess precisely the relationships between the species recorded.

In this note the taxonomic position of the tiny eomyid genus Keramidomys (Hartenberger, 1967) from the Early/Middle Miocene boundary locality of Sandelzhausen in the Bavarian Upper Freshwater Molasse is reexamined. As the chronological dating of the Sandelzhausen fossil site has been modified in the past from formerly the Neogene mammal unit MN6 to now MN5 and thanks to new abundant material this rodent is compared with other European forms. It is shown that the Sandelzhausen eomyid must be called K. thaleri Hugueney & Mein, 1968 on the basis of several morphological dental differences from K. carpathicus Schaub & Zapfe, 1953. This rodent seems to be an immigrant from East Asia into Europe. Even if K. thaleri is known in many European localities, all correlated to MN5, it is always a rare element of European rodent faunas. Differentiation from K. carpathicus is not easy and requires a sufficiently large sample.

Peratherium sp. cf. P. innominatum, a species with an early Wasatchian to Duchesnean range, is present in the Turtle Basin Local Fauna. Two new genera and species of rodents are described: Cristadjidaumo mckennai (Eomyidae) and Passaliscomys priscus (Heliscomyidae). The remainder of the rodent fauna consists of species that are similar to Duchesnean faunas from both the northern Great Plains (Saskatchewan) and from southern California. The probable occurrence of Simimys and Griphomys suggests a slightly greater similarity to the fauna of southern California.

International audience; Cette faune résulte de la brêve exploitation d’un petit niveau fossilifère mis au jour lors de l’ouverture d’une tranchée pour l’installation d’une conduite de gaz. Même si la quantité de sédiment fossilifère accessible était limitée, la diversité de la faune récoltée est du même ordre que celle de localités contemporaines. Parmi les 40 espèces de vertébrés reconnues, quelques unes sont amphibies mais la plupart est terrestre. Parmi elles, des marqueurs biochronologiques tel Issiodoromys pauffiensis Vianey-Liaud, 1987 (Rodentia, Theridomyidae) sont mieux définis. Cette espèce est comparée à la population type du niveau repère mammalien du Paléogène MP 26 (Mas-de-Pauffié, Lot; Chattien inférieur). De plus, des stades évolutifs jusque là inconnus sont décrits pour quelques espèces moins abondantes : c’est le cas d’un rongeur Sciuridae Comtia n. gen., d’une chauve-souris Molossidae (Cuvierimops sp.), d’un probable Talpidae, et du Hyaenodontida Thereutherium thylacodes Filhol, 1876. L’attribution familiale du serpent Platyspondylia Rage, 1974 est discutée. L’un des lézards du gisement pourrait être le plus ancien Shinisauria. La diversité de cette nouvelle faune est comparée avec celle de plusieurs faunes contemporaines (principalement Mas-de-Pauffié, Saint-Menoux, Saint-Henri/Saint-André Mümliswil-Hardberg et Oensingen 11). Le choix de Mas-de-Pauffié comme localité-type du niveau-repère MP 26 est conforté.

We report herein new discoveries of Gliridae and Eomyidae (Mammalia, Rodentia) from the new Early Miocene locality XJ 200604, located northwest to the Burqin city, northern Xinjiang province, China. These specimens represent three taxa of Gliridae, including a new species (Miodyromys asiamediae nov. sp., Microdyromys aff. orientalis and Eliomys? sp.), and four taxa of Eomyidae (Asianeomys aff. engesseri, Asianeomys sp., Keramidomys sp. and Eomyidae indet). The identification of two forms that are closely related to Microdyromys orientalis and Asianeomys engesseri suggests an Early Miocene age of the locality but does not allow a more precise age determination. The new discoveries of Gliridae and Eomyidae again reveal the relative scarcity of the two families in the Early Miocene of Central Asia, in contrast to the coeval rich European record. Such a discrepancy in taxonomic diversity and abundance is hypothesized as resulting from different environmental evolutions during the Early Miocene, most notably the onset of a mid-latitude dry climate in Central Asia linked to combine effects of the Tibetan Plateau uplift and the retreat of the Paratethys Sea.

The oldest mammals of the Betic Cordillera are reported from the Marine-Lagoonal Formation of the internalPrebetic. Only four species were found: Blainvillimys cf. langei, Eucricetodon sp., ex group atavus, Eomys sp., and Gliravus sp. The fauna is dated as Early Oligocene. This age is in contradiction with the previously assumed Chattian age of the base of the Formation, based on benthonic foraminifera found in other localities.

International audience; Le gisement karstique de Blanquatère 1 a livré une microfaune d'âge Miocène moyen, abondante (plus de 6300 dents) et très diversifi ée en rongeurs avec 33 espèces reconnues, parmi lesquelles plusieurs espèces nouvelles de Cricetidae et de Gliridae. Le présent travail complète l'étude initiale par la description de Cricetidae non décrits jusqu'ici, Eumyarion, Democricetodon, Pseudofahlbuschia, des Eomyidae Ligerimys et Keramidomys et des Sciuridae Spermophilinus et Heteroxerus. Cette faune, très riche, fait de cette localité une référence pour le début du Miocène moyen (MN 4/MN 5) en Europe sud-occidentale. La faune inclut des taxons nouveaux et allochtones avec, en particulier, la présence d'un représentant des Myocricetodontinae (Dakkamys sp.), qui résulte d'une probable immigration suite à la fermeture orientale de la Téthys au cours du Langhien. C'est aussi actuellement le site le plus ancien dans lequel cohabitent Ligerimys et Keramidomys. Enfi n, cette localité souligne encore une fois l'intérêt des remplissages karstiques, susceptibles d'enregistrer des occurrences de courte durée de taxons consécutives à des événements géologiques ou climatiques. http://www.mnhn.fr/museum/front/medias/publication/29612_g2010n3a8.pdf

International audience; New material of eomyids from the very Early Oligocene of southern Germany and the late Early Oligocene of France and Spain has been studied. In Germany besides the previously known and unique Eomys antiquus (Aymard, 1853), two other species have been found including an undetermined genus, Eomyidae gen. et sp. indet, with unexpected morphological features that were considered as derived based on our current knowledge. These three species show that at least three immigrant lineages were present as early as the beginning of the Oligocene in Europe. In France and Spain, except for Eomys antiquus which confirms its large geographical distribution, the species found are unlikely to have evolved from the German ones, thus suggesting another immigration wave of eomyids in Europe. Finally, the diversity of the first European eomyids is higher than expected, leading us to consider a more complex evolutionary history than a simple radiation from Eomys antiquus as previously proposed. Despite the limited material available, the undetermined genus, here considered as a likely new genus, shows some clear morphological affinities with the Asian late Oligocene genus Asianeomys Wu, Meng, Ye & Ni, 2006, thus suggesting a possible common Asian ancestor.

Until now there have been no definitive reports of eomyid rodents in the Tertiary of Asia, although their discovery there has long been expected. Four forms of eomyid rodents (Eomys orientalis, sp. nov., Eomyodon sp., Pseudotheridomys asiaticus, sp. nov., and ?Pseudotheridomys sp.) are now recognized in the Oligocene of Nei Mongol, China. These occurrences support the hypothesis of exchange between the European and North American eomyids via Asia. The beds bearing Pseudotheridomys asiaticus and ?Pseudotheridomys sp. at Loc. 77048 appear to be slightly younger than the classic localities at Saint Jacques. The Tertiary deposits at Saint Jacques appear to include at least two horizons: late middle Oligocene and late Oligocene or latest middle Oligocene.

We discovered five new sites with microvertebrates in the western sector of the Madrid Basin, the first found in the area of Talavera de la Reina, that are from the bottom to the top: Aritosa, Cantera de Talavera 1, Cantera de Talavera, Cerro Negro and La Cueva. Its Upper Oligocene age allows to date the lower arcosic unit (MI), three section, of Martin Escorza (1974) in which they appear. In some of these sites we have determined the evolution line: Zssiodoromys paufiensis - Zssiodorornys quercyi that allows us to corroborate its tendendy towards hypsodonty and also to place biostratigraphically with accuracy the sites, respectively, between the MP 26 and MP 27 units, after Schmidt-Kittler (1987) (Cantera de Talavera 1 and Cantera de Talavera) and in the MP 27 unit (Cerro Negro). Moreover, in some of these fauna1 associations we have found another Theridomyidae which belongs to the genera Archaeomys, an Sciuridae, some Cricetidae, one at least belonging to the species Eucricetodon dubius, two species of Eomyidae: Eomys cf. major and Eomys zitteli, (in which we can estimate its tendency towards the increasing size of its successive populations) and an Artyodactyla, Caenotherium sp., of great size. The composition of these fauna1 associations, in which the Theridomyidae are predominant, suggests relatively arid climatic conditions for that age in the area. Furthermore, the presence of two highly hypsodont taxa of Theridomyidae, together with some Cricetidae, and the lack of Gliridae, suggests an open environment