The early gnathostome genus Mesacanthus is well represented in both Lower Old Red Sandstone and Middle Old Red Sandstone assemblages of northern and central Scotland. This ‘acanthodian’ taxon is currently thought to comprise two valid species: M. mitchelli and M. pusillus. Although the whereabouts of the holotype of M. mitchelli (NHMUK PV P560) is known, the syntype material for M. pusillus has long been thought lost. Here we identify at least one specimen that formed part of the original syntype material for M. pusillus, albeit in a slightly different condition than when it was originally figured. This specimen is ROM 25872, which is here designated as the lectotype. A second specimen – ELGNM 1978.191.1 – could represent another of the syntype specimens, but poor preservation quality makes it impossible to be certain. 

La localité fossilifère du Puech de Montredon, désignée plus communément sous le nom de Montredon, est située sur la commune de Montouliers (Hérault) à quelques 300 mètres de la limite avec le département de l'Aude. Elle a été découverte en 1845 par Narbonne, Directeur des Mines de La Caunette, et de très nombreux restes de vertébrés continentaux y ont été extraits. La plus ancienne mention de ce gisement dans la littérature semble être celle de Lartet (1859) qui signale que "M. Jourdan, de Lyon, a constaté à Montredon, près de Bize (Aude), l'association des restes de Dinotherium avec l'Hipparion". 

     The Faunas of Rodents from seven north-african fossiliferous beds distributed from the Middle up to the Uppest Miocene are studied. One genus, seventeen species, one subspecies described are new.
       A detailed description is given of the evolution of the numerous specific lines, systematic groups and communities. The evidence of the strong endemism of the North African faunas of that time compared with those of Europe as well as of Tropical Africa is clearly shown. Special relationships with Asia clearly also appear, mostly in the Middle Miocene and the beginning of the Upper Miocene.
       Using the specific lines with a biostratigraphic purpose gives the opportunity to establish a biochronological scale for the continental formations of the Maghreb. This scale is calibrated by a few absolute datations. These datations, as well as the stratigraphical study of several fossiliferous localities have given the possibility to establish precise correlations with the corresponding scales of Europe and of Tropical Africa, as well as with the marine formations of the Neogene of occidental Mediterranean sea.
       The paleoclimatic data connected with this period in North Africa are explained and the contribution of the micromammals is discussed. 

The geomyoid genus Dikkomys is well represented in a sample from the Black Bear Quarry Il local fauna of Early Hemingfordian age in Bennett County, South Dakota. Isolated unworn P/4's of Dikkomys matthewi WOOD have a prominent median cristid (sagicristid) with a connection to the metaconid and the hypolophid. With wear, P/4 does not become as molariform as P/4 because of this cristid.
A large sample of the Whitneyan beteromyid Proheteromys nebraskensis WOOD contains variants of the P/4 with on incipient sagicristid in approximately 18 percent of the population. The upper dentition and lower molars of Proheteromys nebraskensis are sufficiently generalized to indicate probable ancestry to Dikkomys. 

A sample of 231 isolated teeth of lagomorphs from the upper Miocene of Montredon (southern France), identified as the ochotonid Prolagus crusafonii DOPEZ, 1975, is studied, comparing it with other populations of the same species as well as with its closest species P. oeningensis (KÖNIG, 1825).
The maintenance dining 5 m.y. of a high morphological variability in a group of non-selected features is interpreted as an evolutionary response. This may be related with the heterogeneity and probably too with the regression of the environment. 

The rodents from the spanish locality of Can Ponsic 1 bring new data about some rodents species of the beginning of the Upper Miocene in South-West Europe. The criticims made by Mein and Freudenthal about the validity of the species Hispanomys thaleri from Can Llobateres are not justiíied. The study of the anatomy of the skull of Rotundomys from Can Ponsic 1 gives accurate information about the affinity of this genus with Cricetulus, and shows that the hypothesis, according to which Rotundomys is an ancestral form of the Arvicolids, is unlikely. The systematics of Heteroxerus and the phylogeny of the mio-pliocene Muscardinus species are also discussed. The Can Ponsic 1 locality is a little older than Can Llobateres.

  

Rodents from the new localities of Châteauredon (Alpes-de-Haute-Provence) and La Denise (Bouches-du-Rhône) show more similarities with the rodents known from the Czecho-Slovak locality of Franzenbad than with the species found in contemporaneous Lower Miocene faunas located westward of the present Rhône Valley. This is another data wich support the existance of several biogeographical provinces in Southern France during Lower Miocene. The correlations which have been settled down allow new datations of several formations in Provence and give new information on the Aquitanian and Burdigalian paleogeographies of this region. More precise stratigraphical allocations are given to some other localities of Central Europe. 

The study of another faunal assemblage (mostly macromammals) from Torralba de Ribota (Calatayud, Zara-
goza Prov.) demonstrates the Middle "Burdigalian" age of the deposit, MEIN zone 4a. Some ten genera have been recognized. a.o. Anchitherium, Aceratherium and Lagopsis. 

A new Tertiary megadermatid is described from Rackham's Roost Site, a Pliocene limestone cave deposit on Riversleigh Station, northwestern Queensland, Australia. It appears to represent the first Australian record of Megaderma GEOFFROY, 1810, a genus otherwise known from Tertiary African and European taxa and the living Asian species M. spasma (LINNAEUS, 1758) and M. (Lyroderma) lyra PETERS, 1872. Megademza richardsi n. sp. is one of the smallest megademiatids known. It exhibits a mixture of plesiomorphic and autapomorphic features, the latter appearing to exclude it from being ancestral to any living megadermatid. The new species is one of eight megadermatids identified from the Australian fossil record, most of which are referable to Macroderma MILLER, 1906. 

The fauna studied in the following work involves the dentitions and skulls more or less complete of 5 genera, among which only Cephalomys was previously known by its skull. One must notice that the Salla's species of this genus is a new one. Sallamys, rather small, shows a dentition rather similar to that of Platypittamys Wood from Patagonia. The upper molars, more primitive than those of this last genus, according to the smaller dimensions of the hypocone, retain a distinct metaloph. This metaloph tends to be reduced in a way which may give us a possibility to understand how it disappeared in Platypittamys. The upper P4 can be compared as well to that of Platypittamys as to that of Gaudeamus from the African Oligocene. The lower P4, more molarized than that of Platypittamys, is already moving towards the miocene type of structure. The infraorbital foramen is wide and the insertion of the masseter on the muzzle is spacious. Branisamys, genus of a great size, shows an auditory region partly preserved, peculiarly the promontorium with the fenestra rotunda, entirely of the Hystricognathi type. Upper molars are very clearly pentalophodont. A new reconstruction is proposed for the tooth called Villarroelomys by Hartenberger. This tooth is shown to be a lower D4, perhaps of Branisamys , certainly of a rather nearly allied form, and Hartenberger does agree with the essential part of this new conclusion. Of Incamys, two incomplete skulls are known, each one being admitted to be the type of a distinct species, the first one being I. bolivianus, I. pretiosus the second. The infraorbital foramen is of a great size and the impression of the masseter on the muzzle is spacious. The sphenopalatine foramen is widely developed and of a really very uncommon great size. Only Thryonomys from Africa shows a similar tendency to the enlargement of this foramen, but not so extreme. The main basicranial foramina can be observed. The upper teeth, hemi-hypsodont, show, either a vestigial metaloph, similar to that of recent Thryonomys from Africa, associated with a well developed mesoloph, either a well developed metaloph, while the mesoloph is reduced or absent. Cephalomys was previously known by anterior parts of the skull showing a wide infraorbital foramen and a spacious facial insertion of the masseter. Its lacrymal is of the phiomorph type and the spheno-palatine foramen is seemingly of great size, like in Incamys. The species is new. The varied peculiarities of the upper teeth of these genera can be easily understood if we refer to the plan of the teeth of Phiomys andrewsi from the Oligocene and Miocene of Africa. The structure of this genus, clearly more primitive, still typically brachyodont, shows and clearly explains the fundamental coherence of the varied realisations arised from such a structure. Luribayomys n.g. is known only by an anterior half of a skull without teeth. It is remarquable by the great development of the masseter's insertions on the muzzle and by the lacrymal region, well preserved, typically phiomorphid. The classification previously published by A.E. Wood and B. Patterson is granted in its essential parts, provisionally, but not as a definitive solution. Nevertheless the Dasyproctidae are integrated within the Cavioidea, following the conclusions of Bugge and of Vucetich, reached independently. The conclusion emphasizes the exceptional meaning of the fauna of Salla-Luribay. This shows that Platypittamys, while interesting, can no more be supposed certainly representative of the normal structure of the Oligocene Caviomorph, and not even of their ancestors. The anatomical peculiarities exhibited in these new samples, auditory region, lacrymal, spheno-palatine foramen, reinforce the primitive structural identity with the Phiomorpha. Similarly, the new lower D4 favour very close relationships, ever if the affinities of the D4 has been questioned or minimized by Wood and Patterson. It is certainly possible to admit that parallelism could explain limited similarities, like the presence in North America of Rodents with an hystricomorph type of infraorbital foramen and an hystricognath mandible. But if the parallelism could be a sufficient explanation of the identical association of multiple and complete structures observed in the Caviomorpha and Phiomorpha, all the Zoological systematic would have to be questioned. The last positions of A.E. Wood on the subject (1975) are revised and criticised, and the recent publications studying the problems of distance between Africa and South America in Eocene time, as a consequence of the drift, are quoted; the possibility of transportation by rafts is shown. A new hypothesis is proposed about the interrelationships of Pentalophodont Rodents, with interesting paleobiogeographic implications. 

As a result of the enrichment of eotheriodont material by one of us (P.K.T.), these specimens (essentially Biarmosuchur and Eotitanosuchur) are reexamined and refigured. A reevaluation of their particularities supports the distinction of two families, for which new diagnoses are proposed. This leads us to discuss the affinities of these families, with respect to the sphenacodonts on one hand, and to the South African primitive theriodonts on the other (gorgonopsids and ictidorhinids). This study contains inherent paleogeographic consequences which are considered in conclusion. 

The family Didelphidae is represented by three species in the Sainte-Néboule site, phosphorites of Quercy (lower Oligocene, San Cugat's nivel): Amphiperatherium minutum (Aymard), Amphiperatherium sp. and Peratherium cuvieri (Fischer). Only the first  and  third species are abundant (88 and 97 pieces). This two populations are described. The marsupial fauna of the european lower Oligocene is not recognized in its entirety in this site. 

The complex taxonomic history of the paramyid rodent genus Ailuravus is reviewed. It has been described as Hyracotherium, as a creodont carnivore and as a lemuroid primate - errors at the ordínal level that are most unusual for a rodent. The genus is a member of the poorly known subfamily Ailuravinae, probably derived from some European Early Eocene species of Paramys. Aíluravus was a large arboreal paramyid with highly rugose cheek teeth, very well developed hypocone, and a remarkably weak lower incisor. It was tropical to subtropical. Three named species are recognized, A. macrurus from the Lutetian of Messel; the genotype, A. picteti, from Egerkingen, Buchsweiler and the Geiseltal, slightly later in the Lutetian; and A. stehlinschaubi, new name, from the Bartonian of Mormont-Eclépens and Robiac. One or more unnamed species are present in the Ypresian of Cuis. The species are close to a phyletic sequence. No later representatives of the genus are known. The late Eocene to earliest Oligocene North American paramyid Mytonomys, whose relationships have been obscure, is tentatively referred to the Ailuravinae. 

Abstract not available 

The skull remains referred to the genus Palaeotherium are recorded and described. Biometrical tests are made to elucidate intrageneric allometric relationships and to allow comparisons with various other perissodactyls. Apart from the well known shortness of post canine diastems and deepness of the narial opening, the genus is characterized by a great lengthening of the splanchnocranium, owing to a spreading of the post-orbital facial region, by a reduced area of the eye-socket and by the prevalence of the temporal muscle with regard to the masseter; this original shape of the masticatory apparatus needs to be related to the morphology of the jugal teeth and particularly to their  asymmetrical semi-hypsodonty.
    These animals, whose running ability was evidently poor, appear to have been adapted to rather closed environments, feeding on relatively soft vegetable matter; olfactory sense was likely to play a leading part in interindividual and environmental relationships. Such evolutionary trends might explain the disappearance of most of them, as clirnatic conditions deteriorated at the end of the Eocene, before the "Grande Coupure" which affected mammalian faunas at that time.
      Although the present paper is not directly concemed with phylogenetics, it invalidates the supposed ancestor-descendant relationship between P. castrense and P. magnum, and it suggests a possible emergence of the P. medium lineage from a P. siderolithicum stock. Moreover, the structure of the post-orbital facial area allows the  erection of a new sub-genus, Franzenitherium, for the  species lautricense and duvali.

  

Le Quercy est aujourd'hui un vaste plateau calcaire, parcouru par un réseau karstique actif, pro· fondément entaillé par des vallées aux falaises abruptes, comme celles du Lot ou du Célé. Sur un sol peu épais domine la forêt de chênes, accompagnés de cornouillers, érables, genévriers. La faune est pauvre, peu diverse, et les nombreux chasseurs se satisfont de gibier d'élevage ...
Il y a trente-cinq millions d'années environ, le paysage était bien différent. La période de l'Eocène supérieur, qui s'achevait, avait été chaude et humide, si l'on se réfère à la fois aux paléotempératures (calculées à partir de sédiments marins extra-européens) et aux restes fossilisés de végétaux typiquement tropicaux.
Le Causse du Quercy devait être un plateau très disséqué par la karstification, à surface lapiazée creusée de gouffres en rapide évolution interne, et couvert d'un sol assez épais. Une forêt tropicale humide, avec notamment des Myricacées et des gymnospermes, recouvrait l'ensemble du pays, à peine interrompue au niveau des rares points d'eaux situés dans les bas-fonds. Dans ce cadre vivait une faune considérablement différente de la maigre faune actuelle. Si nous pouvons l'imaginer, c'est grâce aux cadavres des animaux entraînés dans les cavités par les eaux courantes ou les prédateurs, ou bien logeant et mourant dans les milieux souterrains. Nombre de ces restes, fossilisés, sont parvenus jusqu'à nous et sont aujourd'hui l'objet d'étude. 

The Caudata are known by two Salamandridae ; one of them is attributed to the genus Megalotriton. The Pelobatidae form the major part of the Anura ; a few bones indicate also the presence of Neobatrachia. 

A reconstruction of a multituberculate endocranial cast is made on the basis of a complete natural cast prepared from the skull of Chulsanbaatar vulgaris, and other less complete endocasts, all from the Late Cretaceous of Mongolia. The multituberculate endocast is of mammalian pattern but it has retained a therapsid-like lateral profile with a deep rhombencephalon and a shallow telencephalon. It is characterized by: a heart-shaped cross-section of the telencephalon; an extensive lissencephalic neocortex; a very prominent pons placed far anteriorly; a lack of cerebellar hemispheres, and very large paraflocculi. Its structure, very different from the brains of other mammals, suggests thats the Multituberculata branched very early from the main mammalian stock. This supports Simpson's (1945) idea that the Multituberculata should be placed in a subclass of their own: Allotheria MARSH. The endocast and braincase structure show that the Multituberculata had strongly developed senses of smell and hearing. The encephalization quotient of approx. 0.55 evaluated for Ch. vulgaris is relatively high for a Mesozoic mammal. 

Based on material from 30 localities, morphologic dental, cranial and biometric analyses have permitted the characterization of two parallel Issiodoromyine lineages, and also the definition of diverse species representing several evolutive stages. Thus it is that new lineages complete the contribution made by the Theridomyinae and Cricetidae and permit, for the Quercy in particular, additional precision in the biochronologic succession of the localities. One of the lineages is limited to the genus Pseudoltinomys LAVOCAT; the other evolves from the genus Elfomys HARTENBERGER to the genus Issiodoromys BRAVARD in GERVAIS. The latter is affected by profound anatomical changes due to a functional modification of the mastication apparatus. These changes seem to be able to be put in relation with the aridification and cooling of the climate at the end of the Eocene. At the end of the middle Oligocene, a new chewing structure is achieved. It is found in diverse living rodents that inhabit a rather arid steppe environment (Cavia, Pedetes, Ctenodactylus). To these supposed nearby ecologic conditions, these rodents have responded in a convergent fashion. It is possible to attribute to the extreme specialization of Issiodoromys its incapacity to adapt to the new climatic crisis of the end of the Oligocene. The arrival of immigrants may be considered as another cause of its disappearance at this time, complementary or not with the first. 

 Detailed anatomical description of arsinoithere cranial remains from the Lower Oligocene, Fayum Depression, Egypt, provides the basic data for a systematic investigation. All cranial and some postcranial features are assessed from a phylogenetic standpoint. Several soft tissue characters are then added to a cladistic analysis based on 54 derived ungulate morphological characters. The resulting phylogenetic hypothesis implies that perissodactyls, sirenians, proboscideans and arsinoitheres constitute a monophyletic unit (5 synapomorphies). However, increasing the tree length by 3 steps reveals a closer association between hyraxes and perissodactyls. Nevertheless, 13 synapomorphies link proboscideans, sirenians and  arsinoitheres to the exclusion of all other ungulates. Form of the sphenopalatine and ethmoid foramina, recurved posttympanic process, absence of a fenestra rotundum in the petrosal, vestigial paroccipital process of the exoccipital and the highly unusual absence of a hypoglossal foramen in the skull, imply a robust sister-group relationship between arsinoitheres and proboscideans. In this analysis artiodactyls share only one derived character with all other ungulates studied. Monophyly of Ungulata, including Artiodactyla, is therefore only weakly supported. It is argued that pedal anatomy of hyraxes is non-homologous with that of Tethytheria. Arsinoitherium should now be classified within Tethytheria, sharing a sister-group relationship with Proboscidea. Hyraxes are excluded, thus refuting the concept of Paenungulata. However, monophyly of the wider concept, Pantomesaxonia, containing hyraxes, perissodactyls, sirenians, proboscideans and now, arsinoitheres, is supported by this study.