On the Track of Ice Age Mammals justifie pleinement son titre car l'auteur, Anthony J. Sutcliffe, apporte au lecteur faits et interprétations qui l'amèneront à s'intéresser encore plus au passé récent et à l'avenir de son environnement et à la question de l'impact de l'homme sur la nature. Après les chapitres qui présentent les temps glaciaires et les divers témoignages qui nous en sont parvenus, les cinquième et sixième apportent les informations nécessaires à la compréhension des résultats que nous donnent les chercheurs: principes, moyens d'étude et limites des méthodes, difficultés de l'intégration des données dans un cadre stratigraphique, variabilité des signaux climatiques, variabilité de leur intensité selon l'endroit par rapport au centre de la glaciation, complications liées à la qualité inégale de l'enregistrement géologique, en mer et sur le continent. 

Messiphoca mauretanica nov. gen., nov. sp. représente le premier Phocidae fossile recensé en Afrique du Nord. Provenant du gisement sahélien (Miocène supérieur) de Raz-el-Aïn (Algérie), il est connu par quelques os du membre antérieur (humérus, radius, ulna), quelques vertèbres dorsales et un crâne très fragmentaire. La description de cette forme nouvelle amène à considérer Messiphoca mauretanica comme un Monachinae archaïque proche de l'origine du groupe Pliophoca - Monachus. L'incidence de cette interprétation d'un Phocidae «pré-Messinien ›› sur la crise de salinité du Messinien est aussi envisagée. 

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.

  

Until now Aplodontidae of the European Oligocene have been documented by four species only. The phylogenetic relations remained obscure. as the distribution of only one species has been known in some detail. New material made it possible to define the stratigraphic range of two of the already existing species (Plesispermophilus angustidens, Sciurodon cadurcense) and to follow their development during the Oligocene beginning with the event of the « Grande Coupure ››. Sciurodon remained nearly without change until the end of the Middle Oligocene. Plesispermophilus angustidens split into two distinct phyletic lines, one of which (P. macrodon n. sp.) reaching considerable size, is represented till the beginning of the Upper Oligocene (Pech de Fraysse, Gaimersheim). The other line leads to Plesispermophilus ernii (basal Upper Oligocene of Burgmagerbein 1. terminal Upper Oligocene of Coderet). Besides the already known forms a new small-sized species (P. atavus n. sp.) is described, which by its primitive features closely resembles the genus Plesispermophilus. Two other small-sized species already known from the Upper Oligocene (? P. argoviensis) and Lower Miocene (? P. descedens) seem to be closely related to the new species. It cannot be decided whether they are descendents of this line or have developed independently, because of their poor fossil record.
Comparison of the evolutionary modalities in the different phylogenetic lines reveals general trends. the most striking of which is the complication of the tooth pattern by the development of additional crests. In the lower molars the cusps diminuate in size and are more and more transformed into ridges. ln addition new connection between the crests appear. in the upper molars, the « selenodont » shape of the teeth becomes more and more dominant, and in the two main evolutionary lines of Plesispermophilus the metaconulus becomes duplicated. A further evolutionary trend is the size increase of the premolars compared to the molars, which is even more pronounced in the Miocene Aplodontidae.
Phylogenetic relations between the primitive Plesispermophilus and certain « prociurines ›› of Northern America as well as between Plesispermophilus (P. angustidens) and more progressive forms of the Upper Oligocene (P. ernii, P. macrodon n. sp.) can be documented. In this light, the taxonomic distinction between Prosciurinae (bunodont) and Allomyinae (selenodont) sensu Rensberger 1976 can be shown to be artificial, because it separates forms from each other, which are evidently closely related. Consequently the separation into two subfamilies has been abolished. 

The Las Águilas site near Porvenir de Jalpa, Coahuila, Mexico, is extremely rich in tetrapod remains comprising both bones and trackways of several dinosaur taxa of late Campanian age. Within a 50 m thick section we identified at least nine layers with dinosaur bone assemblages. In one of these the dinosaur bones are associated with remnants of eusuchian crocodilians, turtles, plesiosaurs, pterosaurs, tyrannosaurids, dromaeosaurids, parksosaurid, hadrosaurids, ceratopsids, and ankylosaurs. This layer is also rich in coprolites of turtles, crocodilians and likely theropods, thus providing evidence for the wealth of Late Cretaceous vertebrate life in the area. 

A general view is given of the vertebrate faunas, Cretaceous to Quaternary of age, found in Columbia and of their principal characteristics. This view leads to the discussion of the isolation of the South American continent and of the role played by the Bolivar syncline with respect to North American immigrants during the Oligocene. The absence of marine deposits of Oligocene age in the north and northwest of Columbia suggests the possibility of a communication with Central America. This communication would have permitted the passage of hystricomorph rodents, of platyrrhine monkeys, and of colubrids. The non-occupation, until then, of the ecologie niches of these groups would have favored their installation beside the indigenous fauna. In this hypothesis it would no longer be necessary to admit that these vertebrates arrived as «island hoppers ››. The eco-biologic conditions would explain the absence of large-sized forms of North American origin. 

The intensive exploration of the Pliocene Hadar Formation, rich in hominid remains, led us to the discovery of several micromammals levels. ln some of them, rodents are very abundant. The stratigraphic repartition of these levels do not cover the whole fossiliferous series of the formation but takes place only in the sedimentary members from Sidi Hakoma and Denen-Dora (rancing from 3.1 - 3.2 MY to 2.8 - 2.9 MY, according to the recent geochronological data). During this gap of time, the species do not show morphological changes, what allowed us to gather, in the same taxa, forms of slighty different ages.
Two striking facts, giving a lot of indications, characterize these small rodents'faunas. First, we notice the domination of the Muridae, as well on a qualitative way (number of species) as on a quantitative one (number of individuals). Then, it appears that, until now, two genera of these murids were known only in the south-western asiatic regions. So, we can suppose continuous biotops between Africa and Indian Subcontinent before 3 MY. In this hypothesis, the hominids had already the possibility to leave their african « cradle ››. Finally, almost all studied genera are still represented at the present time. This fact, previously observed in Laetolil, Omo, Olduvai contributes to remove hope of establishing a biochronological scale based on rodents, in tropical zone. Nethertheless, that allows to try a reconstruction of the palaeoenvironnement, by using the principle of actualism.
  

The Montredon local fauna yielded very rare bats, represented by damaged isolated teeth. Only a few documents are available for this period of the European Neogene. ln this poor state of knowledge, the material represents three undetermined species, a supposed molossid and two vespertilionids. 

The rodent-fauna (Cricetidae and Gliridae) recently found at Castell de Barbera (Spain) is similar to those from the other locslities of the Valles - Penedes - Can Ponsic 1 and Can Llobateres - : same composition and similar evolutionary level of the different species. On the other hand this fauna is different from those of Upper Vindobonian and Vallesian localities of the Calatayud - Teruel area. Castell de Barbera has an intermediate chronological position between the localities of Anwil (Switzerland) and Can Ponsic 1. It is still not possible to validate or invalidate the initial attribution based on absence of Hipparion of Castell de Barbera to the Upper Vindobonian. 

Les Pistes de Vertébrés du Stormberg Supérieur ("Trias terminal à Rhétien"), ou Quthingien

Si les zones du Stormberg inférieur se sont révélées contenir de nombreuses traces, surtout dans les faciès dits "Molteno moyen et supérieur", représentant apparemment la base du Keuper, il est frappant de voir pratiquement l'ensemble de cette grosse faune "Molteno" disparaître avec la fin de cette période, que nous avons appelée le "Maphutsengien".

Dès les premières zones du Stormberg supérieur, que nous nommons le"Quthingien" la zoocénose et la phytocénose, en même temps que les données d'ensemble manifestées par l'environnement, sont modifiées. Nous ne verrons plus guère de dépôts marécageux à flore riche et variée, parfois même luxuriante. Les fougères elles-mêmes ont disparu. Elles sont remplacées par de maigres plantes, aux feuilles très souvent filiformes qui paraissent témoigner d'un climat continental. Le sol est devenu de plus en plus rouge, avec des variations latérales beaucoup plus accusées. Les fleuves amenant des galets des monts du "Grand Sud" ont tari. La faune va en subir les conséquences. Certaines des espèces se révèleront sautillantes ou coureuses, pour un grand nombre plus légères et pour la quasi-totalité d'apparence carnivore ou entomophages, les phytophages devant se contenter d'un régime ingrat,difficile ou à tout le moins irrégulier,les dépôts le montrent.

C'est dans ces conditions que s'inaugure notre Etage nouveau,quelque peu discordant sur les zones A/5, A/6 ou A/7 du Stormberg inférieur (Maphutsengien). Le Stormberg supérieur (ou Quthingien) commence avec le paléopaysage remarquable dit de Moyeni, que nous allons maintenant étudier, typologiquement, avec ses homologues du même âge. Quelques 38 types d'animaux tous nouveaux vont défiler à nos yeux lors de la zone de base de cet Etage, ou zone B/1.

L'on nous avait proposé d'intituler ce Ile Tome de la série : "La grande Dalle de Moyeni et ses homologues. Paléo-spectacles, scènes et paysages animaux au Lesotho à l'approche du Trias finissant". Nous avons préféré garder le sous-titre plus haut, peut-être plus prosaïque.

Un llle Tome est en préparation : "Les développements ultérieurs et terminaux de la faune du Gondwana".

  

Two species lineages of North American late Paleocene Plesiadapis exhibit a pattern of size divergence from a common ancestral lineage. Time series of fossils in each of these lineages are analyzed to test the idea that size divergence represents competitive character displacement. The critical factor in a test of character divergence is showing that divergent lineages evolved directionally rather than randomly (multifactorially). Analysis of evolutionary rates and their temporal scaling in Plesiadapis shows that both divergent species lineages have the scaling slope expected for lineages evolving randomly rather than directionally, and size divergence in Plesíadapis does not represent character displacement. Rates of evolution commonly observed on a per-generation time scale are high enough to produce character displacement within a few generations. Thus character displacement is not likely to be visible on scales of time that can be studied in the fossil record. 

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. 

About the early radiation of Rodents, we have now from the early tertiary of Asia, a new fossil record, and
we can do new interpretations. First the problem of the origin of Rodents is studied : considered as a sister group of Lagomorpha, it is possible to find their ancestors between the Mixodontia. Second the new facts about the origin of modern groups of Rodents are reviewed. A general scheme of this diversification can be proposed. 

This paper is mainly devoted to the systematics of rodents from two middle Eocene (Bartonian) localities: Chéry-Chartreuve and Rocourt-Saint-Martin (Aisne, Eastern Paris Basin). These two localities are stratigraphically located slightly above the Auversian sands. The two faunas, which comprise 11 and 8 taxa, respectively, are very different in their composition. That of Rocourt-Saint-Martin shows strong similarities with that of the geographically very close locality of Grisolles, referred to the MP16 mammalian Reference level. The very distinct fauna of Chéry-Chartreuve includes a new species of Ailuravinae, Ailuravus nov.sp, and some teeth of the theridomyid Protadelomys, which represent archaic elements in the fauna. The most abundant species of the locality represents a new genus of primitive Theridomyidae. The presence of some teeth belonging to a new species of large Remyinae, Remys nov. sp., of Elfomys engesseri HOOKER & WEIDMANN, and a population of small dimensions referred to the genus Estellomys allow a correlation with Les Alleveys (Switzerland), with however some differences that would indicate an older age for Chéry-Chartreuve. Situated at the base of the "Marinesian" from the Bassin de Paris, this fauna is unquestionably different from those referred to the MP16 reference level and could represent an older level for which the macrofauna remains very poorly known. Conversely, the comparison of rodents from La Livinière II with those present in MP16 faunas, especially those of Robiac (Gard), shows a great similarity between both localities. This casts doubts on whether to keep this La Livinière II faunule to define the current MP15 reference level, while the biostratigraphical position of Pontils 26 (Spain), previously referred to this level, is reconsidered. Chery Chartreuse could be a good candidate for a new definition of the MP15 reference level. 

Description, for the first time, of the skull of Ruscinomys Depéret on the basis of a nearly complete specimen, and description of a new facial part of a Megacricetodon Fahlbusch skull (material from upper Miocene, Spain). New description of the skull (facial part) of " Cricetodon" incertum Schlosser on the basis of the specimen from the Oligocene of Quercy phosphorites already published by S. Schaub.
Comparison of the skull of “ C. ” incertum with that of the asiatic genus Cricetops Matthew and Granger and that of the North-American Eumys Leidy. These three genera of similar age display very distinct characteristics; their common origin must go back to the Eocene, as Wood believed.
Comparisons of the auditory regions of Ruscínomys and of Megacricetodon where important differences are noted. Comparison of the Cricetodontines from European Miocene with contemporary Cricetines. Contrary of the opinion held by Schaub, their anatomical differences do not seem suflicient to warrant the contention that none of the Cricetines derive from a form close to one of the known Cricetodontines. 

Le volume 11 du «Handbuch der Paläeoherpetologie», consacré aux «Serpellles» et redigé par Jean-Claude Rage, apporte une remarquable information sur ce groupe particulier de reptiles dont on ne pouvait guere se faire une idée très précise à partir, par exemple, des seuls chapitres des traités classiques de Paléontologie et de Zoologie. 

Two steps can be distinguished in the history of the first invasion of western and south western Europe by the arvicolines. The first step corresponds to the installation of these rodents with the immigration of Promimonys inxuliferus Kowalski, then of Mimomys stehlini Kormos and of Mimomys gracilis (Kretzoi). The second is characterized by the establishment of a geographic differentiation in the arvicoline fauna between the south of France and Spain, from where are described new species of Mimomys (Mimamys cappettai, Mimomys septimanus, Mimonys medasensis), and the rest of France, where are found only elements already known from central Europe or England (Mimomys polonicus Kowalski, Mimomys pliocaenicus F. Major, Mimomys reidi Hinton, or forms very close to the latter). This geographic differentiation, which is very certainly the consequence of the division of Europe into distinct climatic provinces, one of them being the southern province comprising at least Spain and southern France, could result from a cladogenetic evolution of Mimomys stehlini and Mimomys gracilis after their immigration. The present work is also a contribution to the search for correlations between the diverse micromammal localities of the latest Pliocene (or early Villafranchian) and of the early Quaternary of Europe. 

Nyctereutes megamastoides (Pomel) from the Villafranchian of the Auvergne and from Saint-Vallier presents cranial and dental characters sufficiently close to those of the late Pliocene canid from Perpignan (Roussillon), described by Depéret under the specific name of Canis donnezani belonging to the same genus Nyctereutes. The extinction of the European "Nyctereutes" group seems due to the too great alimentary specialization of this canid, whereas the Asiatic lineage represented in the Villafranchian by Nyctereutes sinensis Schlosser and at present by Nyctereutes procyonider Gray was able to maintain itself probably by means of a profound change in its alimentary regime. 

New Dendromus species (Rodentia, Muroídea) from Langebaanweg (Pliocene, South Africa). Stratigraphical and paleoecological consequences.

Two new species of Dendromus are described from the Langebaanweg site which precises the evolutionary trend among this genus in South Africa and gives further paleoenvironmental indications. Two evolutionary stages are described: D. darti nov. sp. shows low-crowned molars with bunodont cusps and its more closest relative would be D. melanozis from the Cape region. On the contrary, D. averyi nov. sp. is more lophodont and is better related with the modem D. melanotis. Both species are at a less evolved stage than the Dendromus sp. from Laetolil Beds at Laetoli. The Langebaanweg deposits cannot still be dated by biostratigraphy but they clearly cannot be older than the basis of Pliocene times. The association of Dendromus and Mystromys in the same levels indicates a grassland environment with woodland patches as well as probable swamps. 

La faune d'artiodactyles de Ste-Néboule, qui comprend neuf espèces, présente de nombreux
points communs avec les faunes habituellement rattachées au Ludien supérieur, telles celles de La Débruge ou de Montmartre. A l'inverse de ces localités, on ne connaît pourtant, à Ste-Néboule, ni Oxacronae, ni Anoplotheriinae. Parmi les espèces du gisement se trouve une nouvelle espèce du genre Mouillacitherium (M. schlosseri n. sp.), cette forme devant être interprétée comme le dernier représentant du rameau. Nous faisons connaître par ailleurs la presque totalité de la denture du Dacrytherium saturninii, espèce qui était à ce jour très imparfaitement documentée. Ste-Néboule est, d'autre part, la seule localité où l'on peut signaler l'association probable de deux lignées du genre Amphimeryx. Les primates sont peu diversifiés à Ste-Néboule, puisque le groupe est limité au seul genre Adapis. Les genres Microchoerus et Pseudoloris, que l'on sait pourtant être représentés dans des gisements dâge voisin (Microchoerus ornatus à San Cugat de Gavadons et Mormont-Entreroches, Pseudoloris reguanti à San Cugat de Gavadons, Pseudoloris cf. reguanti à Neustadt ; cf. Louis et Sudre 1975) sont absents dans les faunes du Quercy de cette période.