Confident attribution of bipedal tridactyl dinosaur tracks to theropods or ornithopods can be challenging. Here we describe trackways produced by tetanuran dinosaurs, previously attributed to hadrosaurs, from Coahuila State, northeastern Mexico. Multiple trackways headed in the same direction suggest gregarious behaviour in these late Campanian theropods.  

Three erinaceomorph species are known from the early Middle Eocene of Grube Messel near Darmstadt, Germany, which are referred to the family Amphilemuridae. Pholidocercus hassiacus, Macrocranion tupaiodon, and Macrocranion tenerum showed extraordinary adaptations to their different life strategies, and several of their specializations are unknown among living insectivores. Pholídocercus was a well-defended robust animal with an opportunistic feeding strategy. Macrocraníon zupaiodon was a slender forest floor-dweller with saltatorial specializations to escape from predators; fishes were the preferred component of its omnivorous diet. Macrocranion tenerum exhibited a combination of both survival strategies, extremely elongated hind limbs for rapid and even ricochetal flight and a spiny exterior as an effective protective device; it was probably specialized for feeding on ants. Thus, closely related, omnivorous-insectivorous forest floor-dwellers could exploit the Messel ecosystem. 

Morphological and biometrical description of skulls, teeth, and limb bones of extant and fossil Old World herniones (including E. hydruntinus) and of New World 'stilt-Iegged' and other slender species from Blancan to Holocene. An Appendix presents ways in which the approximate size of some missing bones or dimensions may be deduced from available ones.

The discussed and/or illustrated fossils were found in Bolivia (Tarija), Canada (Yukon), China (Choukoutien, Gulongshan, Jiling, Loufangzi), Ecuador (Oil Fields), Ethiopia (Melka Kunturé), France (Lunel-Viel), Germany (Süssenborn), Greece (Agios Georgios, Petralona), Hungary (Dorog), Italy (Romanelli), Mexico (Cedazo, San Josecito), Mongolia (Sjara-osso-gol), Spain (Venta Micena), ex-Soviet Union (Akhalkalaki, Binagady, Chokurcha, Chukochya, Kabazi, Kolyma, Krestovka, Kurtak, Staroselie, Tologoj), USA (Alaska, Arkalon, Cedar Meadow, Channing, Conkling, Dry Mountains, Hay Springs, Leisey Shell Pit A, Lissie Formation, Natural Trap, Pool Branch, Powers Ranch, Rock Creek, San Diego, Santo Domingo, Seymour Formation, Shelter, Slaton, Trinity River). Numerous raw or statistically elaborated data are given in Tables.

There is no evidence for the existence of Old World hemiones in the New World nor of 'stilt-Iegged' equids in the Old World. The first 'stilt-Iegged' equid was found at Santo Domingo, New Mexico, and is believed to be Late Blancan. It was probably at the origin of E. calobatus (Arkalon, Rock Creek) and of the smaller E. semiplicatus (Channing, Rock Creek). Slender, but not 'stilt-Iegged', equids found at Natural Trap, Wyoming, ca. 12 ky ago belong to Amerhippus. AlI these species share with Oid World Sussemiones (and some hemiones) peculiar patterns on the lower cheek teeth.

The slender Equus sp. B of Leisey Pit A, Florida, ca. 1.2 Ma, as weIl as Amerhippus francisci and E. tau (probably a senior synonym of E. quinni) share conventional lower cheek teeth patterns. The skulls of A. francisci and E. tau, however, are quite different.

Paleontological data suggest a common origin of Amerhippus, Sussemiones, and 'stilt-Iegged' equids during the late Blancan. Old World hemiones seem to have differentiated later. 

Since the 19th century, thousands of footprints were observed in the geological series of the French Mesozoic. All are located in the Triassic and Jurassic. After a promising beginning, in France, it is only a few papers which will be published in the first half 20th century, unlike the USA and of others countries of Western Europe. One ought to wait about 1950 for a revival and now they are nearly 200 papers which were devoted to the ichnofossils. The literature abundance and the renewed interest of the naturalists for the palichnologic studies decided to us to write a synthesis work. This one begins with a stratigraphic inventory in which, localisation, age and paleontological contents of about 180 fossiliferous sites are specified. After having pointed out the followed methods, the footprints paleontological interpretation is then approached in detail and the results obtained are replaced in stratigraphy to deduce the fauna evolution during the Mesozoic. So, it appears that Ichnologic data, more varied and rich in the Triassic and Liassic than those relating to the bones, very rare for the considered periods, are very informative. The middle Triassic (Anisian-Ladinian), thus reveals Cotylosauria, Lepidosauria, Crurotarsi with Rauisuchia, Ornithosuchidae, Crocodylia and Dinosauromorpha more the "Prodinosauria": Dinosamiforme whose skeletons are known in Argentina but only in Ladinian. The rather fast domination of Dinosaurs during Norian is also as well shown. The almost exclusive presence of their footprints, up to fifty cm long, in the Lower Hettangian indicates their supremacy in the environments. Footprints characterise not very deep life places located between inter-supratidal limits and often out of water. Sedimentologic and Palaeontologic studies showed that they were great coastal spaces during Middle Triassic, flood-plain with sebkhas while Upper Triassic, and a large !!coastal marsh!! in Grands-Causses during Liassic in which, mainly, fine stromatolithic layers were deposited. During the same periad, bay beaches spread in Vendée. During the Middle Jurassic, they are also brackish to lacustrine environments and recifallagoons in- the Upper Jurassic. Numerous measurements of the footprints and trackways directions showed that the animaIs moved there in weil defined directions, for long periods. They seem due to the palaeotopography of the life environments relatively stable. Also, the discovery of vegetal radicular networks and small footprints far away from the continental borderlands has suggested that the animals continuously lived in these palaeoenvironnements, belonging to large ecosystems, where the sedimentation rate was weak. This explains that thebadies could not fossilize there but only their footprints through the cyanobacterian action in main cases. From the vertical distribution of different ichnospecies, defined with adapted statistical methods, explained in this work, a palichnostratigraphy was established for the Middle Triassic. Although the footprints are also abundant in Hettango-Sinemurian of "Grands-Causses" and the Vendée, it was not possible, up to now, to establish any zonation in this series; Probably because the palichnofauna is too little diversified there, currently reduced to a majority of Theropods II-IV tridactyl traces.
  

Previous chronological arrangements of South American Quaternary land mammal faunas are appraised on the basis of current geological and paleontological data. Three South American late Pliocene-Pleistocene land mammal ages are conventionally recognized, from oldest to youngest, the Uquian, Ensenadan, and Lujanian ; all are defined on Argentine faunas.

     The Uquian is based fundamentally and historically on the fauna from the Uquía Formation in Jujuy Province, northwestern Argentina. Important known formations in Argentina yielding Uquian Age faunas include the sub-surface Puelche Formation (or Puelchense) near the city of Buenos Aires, and the Barranca de Los Lobos and Vorohué Formations between Mar del Plata and Miramar, Buenos Aires Province. A tentative subdivision is propos-ed for the Uquian into three subages based on knowledge of the Mar del Plata-Miramar sequence, from oldest to youngest, the Barrancalobian, Vorohuean, and Sanandresian. In Argentina the Uquian is presently marked by the first known record of Scelidodon, Hydrochoeropsis, Ctenomys, Canidae, Ursidae, Gomphotheriidae, Equidae, Tapiridae, Camelidae, Cervidae, and the last known record of Thylatheridium, Thylophorops, Dankomys, Eumysops, Pithanotomys, Eucoelophorus, Hegetotheriidae, Sparassocynidae, and Microtragulidae.

The Ensenadan Age is based on the fauna from the Ensenada Formation near the city of Ensenada, Buenos Aires Province. In Argentina the Ensenadan is marked by the first known record of Lomaphorus, Neothoracophorus, Plaxhaplous, Cavia, Lyncodon, Lutra, Galera, Smilodon, Dicotyles, Lama, Vicugna, the last known record of Orthomyctera, and the only known record of Brachynasua.

     Typícal beds of late Lujanian Age in Argentina consist of fluvial deposits occupying stream channels, and shallow basins, often incised into beds of early Lujanian (i.e. Bonaerian of early workers) and Ensenadan Age. The Lujanian Age is based on a fauna from beds along the Rio Luján, about 65 km west of the city of Buenos Aires, Buenos Aires Province. The Lujanian in Argentina is marked by the first record of Equus, Chlamyphorus, and Holochilus, and the last record of Megatherioidea, Glyptodontoidea, Arctodus (=Arctotherium), Smilodon, Litopterna, Notoungulata, Proboscidea, Equidae, Morenelaphus, and Palaeolama.

   These land mammal ages are often difficult to recognize in other South American countries. The compositions of South American Pleistocene faunas vary with the environment. Some taxa were widely distributed in fossil deposits throughout the continent, but their occurrences need not reflect synchroneity. This is a result of changing climates and habitats in time. Consequently, proposed intracontinental correlations need confirmation based on magnetostratigraphy and a radioisotope time scale. Paleontologic characterizations of these land mammal ages (i.e. first and last record, and guide fossils) are useful for much of Argentina, but extensions to most of the other parts of South America are at best tenuous.

The majority of known non-Argentine Pleistocene faunas are believed to be Lujanian in age. Possible non Argentine early Pleistocene (Uquian) faunas include Ayo Ayo and Anzaldo in Bolivia, and Cocha Verde in southern Columbia. A possible middle Pleistocene (Ensenadan or early Lujanian) fauna is the Chichense of Ecuador. Paleomagnetic and radioisotopic date (MacFadden et al., 1983) clearly indicate that the greater part of the Tarija fauna (Bolivia) is Ensenadan in age.

  The end of the Pleistocene and beginning of the Holocene in South America is marked by extinction of nearly all large mammalian herbivores and their specialized large predators. Radiocarbon age determinations suggest that large scale extinctions of megafauna occurred between 15,000 and 8,000 yrs. B.P. (years before present). 

A new genus, Eppsillycteris, is erected for Adapisorex? allglicus COOPER, 1932, from the earliest Eocene Blackheath Beds of Abbey Wood, London, England. Various derived character states indicate that it belongs to the order Chiroptera (bats) rather than to the extinct "insectivore" family Adapisoricidae. Other derived character states are shared with fossil and modern members of the family Emballonuridae. Placement of the new genus in this family extends the record of the Emballonuridae back in time by about 10 million years. It is the earliest record of a modern bat family and one of the earliest bats. This implies that the differentiation of at least some modern bat families took place in the Palaeocene, where no authenticated records of bats yet exist. The primitive characters of the earliest bats make the family Nyctitheriidae an unlikely stem group for the order Chiroptera. A tentative plausible alternative exists in some unnamed upper molars from the Palaeocene of Walbeck, Germany. Wyollycteris chalix, described as a bat from the Late Palaeocene of Wyoming, U,S.A., fits better in the family Nyctitheriidae. 

The Pantolestidae from the middle eocene of Bouxwiller are the subject of a detailed study. Buxolestes hammeli (n. g., n. sp.) is not closely related to any other European or North American form described until now; it presents, however, some characters in common with Pantolestes, a form of the same age from North America. A parallel evolution from a common ancestral form could explain this ressemblance.
Another form (gen. and sp. indet.) accompanies Buxolertes hammeli in the Bouxwiller fauna.
  

The Laprade fauna is chronologically situated between those from Egerkingen and Lissieu and consequently, is close to the MP 14 reference-level of the European mammalian biochronological scale (Symposium of Mainz, 1987).
This new fauna is presently the oldest known in the Quercy phosphorites, formerly the Le Bretou fauna (MP 16) was considered as the oldest one. The Laprade fauna includes 21 species which belong in 7 mammalian orders (Marsupialia: Amphiperatherium bastbergense, Amphiperatherium goethei; Apatotheria: Heterohyus (Gervaisyus) pygmaeus nov. subgen., nov. sp.; Lipotyphla: Saturninia cf. mamertensis, Saturninia cf. intermedia; Chiroptera: Vespertiliavus lapradei nov. sp.; Rodentia: Protadelomys cf. lugdunensis, Elfomys nov. sp.; Primates: Nannopithex cf. filholi, cf. Pseudoloris or Pivetonia; Perissodactyla: ?Palaeotherium ?castrense, small-sized Palaeotherium sp., Plagiolophus sp., Anchilophus sp.; Artiodactyla: Dichobune cf. robertiana, Mouillacitherium cartieri, Tapirulus cf. depereti, Mixtotherium priscum, Pseudamphimeryx schlosseri, and Artiodactyla indet). Sixteen of these species are mentioned for the first time from the Quercy faunas.
The recognition of a new apatemyid, Heterohyus (Gervaisyus) pygmaeus nov. subgen., nov. sp., attests to an early origin of a lineage known in the Late Eocene. The emballonurid bat Vespertiliavus lapradei nov. sp. is presently the earliest record of this genus and family. This Auversian fauna leads to discuss the age of taxa showing archaic features. These taxa were defined on specimens collected in the Quercy during the last century and have never been found in the Quercy localities recently investigated. This fauna bears also evidence of a karstic filling episode older than those previously dated by fossils in the Quercy Jurassic. 

In the course of a revision of the Equoidea numerous dentitions as well as a partial skeleton of a Phenaeodont were discovered from the Middle Eocene lignite beds of the Geiseltal locality. These fossils are recognized as a new genus and species of Phenacodontidae : HaIlensia matthesi n.g. n.sp.. The species is present in the « untere und obere Unterkohle ›› (uUK, oUK = the lower and upper part of the Lower Coal Seam) as well as in the « obere Mittelkohle ›› (oMK = the upper part of the Middle Coal Seam). Two fragmentary upper jaws described and figured by Matthes (1977) as Propachynolophus gaudryi are also belonging to Hallensia matthesi. Thus the decisive argument for classifying the " Unterkohle " of the Geiseltal section as Lower Eocene has to be dropped. Another relict form of the Geiseltal is Esthonyx tardus n. sp. documented by a fragmentary mandible coming from the « untere Unterkohle ››. This is the latest Tillodont from Europe. Contrasting to E. munieri from the european Lower Eocene the dentition of E. tardus is morphologically more progressive. 

We present here a new updated counting of the perissodactyls of Robiac, the type locality of the MP 16 level of the biochronological scale of paleogene mammals and that of the Robiacian stage of Eocene Land Mammals Ages in Western Europe.
The outcrop of Robiac consists actually of two 500m apart loci, Robiac-Nord and Robiac-Sud, considered of the same age according to the current discriminating power, and is dated from -38,7 MA after the last faunal, magnetostratigraphic and climatic calibrations.
It has yielded a very abundant and rich of 21 taxa perissodactyl fauna, topped by the giant Lophiodon lautricense, last representative of the family Lophiodontidae, of which it is the last proved deposit. The Palaeotheriidae are much diversified with 5 genera and 9 species of "Pachynolophinae", 3 genera and 10 species of Palaeotheriinae. Nine taxa have been defined from Robiac: Chasmotherium depereti n. sp., Palaeotherium castrense robiacense Franzen, 1968, the genus Leptolophus Remy, 1965 with the species L. stehlini Remy, 1965 and L. magnus Remy, 1998, Anchilophus (Paranchilophus) jeanteti Remy, 2012, Metanchilophus chaubeti Remy, 2012, Lophiotherium robiacense Depéret, 1917 and Pachynolophus gaytei n. sp.
The faunal Robiac cenogram with the associated flora testify to a hot, wet and forestal environment, likely corresponding to a short warming climatic phase; the broken up fossil bones should have been carried away and then gathered in swamp areas along the banks of a meandering river.
The swarm of mammals of Robiac, the richest of contemporaneous deposits, has been followed by a drastic drop in perissodactyl diversity at the MP 17A level; a crisis which could have originated in a renewal of the global Eocene cooling. Fons 4, the type-locality of this level, is largely scarcer in perissodactyls and its cenogram testifies to a less diversified fauna, with on the whole smaller species, that likely means a cooler and drier climatic environment; a new perissodactyl diversification occurred but later.
  

A new European rodent from the middle Eocene of Spain, Zamoramys extraneus n. gen., n. sp., appears to be closely related to the middle Eocene chapattimyid rodents of Indo-Pakistan. This contradicts the generally accepted paleobiogeographic hypothesis of a Tethyian barrier between Europe and Asia isolating Europe during the middle Eocene. Because of this barrier, some authors have proposed that European and Asian rodents were not closely related, their similarity being the result of morphological convergence. Here monophyly has been tested, using the parsimony criterion, based on an analysis of dental characters (including discussing of homology and the validity of some characteristics). Our results indicate a phylogenetic relationship among the Asiatic Ctenodactyloidea, Zamoramys from Spain, and the European endemic Theridomyoidea. We also conclude from our analysis that theridomyoids and European ischyromyoids are probably not closely related phylogenetically. 

There are very few birds in the site of Sainte-Néboule. They belong to three species already known in the "Phosphorites" : Paraortyx brancoi, Aegialornis broweri, Cypselavus gallicus, and to one new species, Recurvirostra santaeneboulae. The comparison of some different bones of the genus Cypselavus with some Apodiformes and Caprimulgiformes shows that this genus must be classified in the order Apodiformes. 

The Tafna Basin corresponds to the lowlands, which are located in front of Tessala and Traras ranges, below the Tlemcen mountains, Algeria. This basin displays a complete sedimentary cycle dominated by lagoonal-fluvial and marine deposits. The continental formations located at the base of these deposits are mainly composed of alternating sandstones and clays. An early late Miocene age has been previously attributed to them, based on direct correlations with marine deposits. Search for micromammal fossils led to the discovery of three different rodent species from a single level of the Djebel Guetaf section, located at the bottom of these deposits. The rodent assemblage indicates a late Miocene age. Combined magnetostratigraphical and biostratigraphical investigations were carried out to provide a more accurate age control of these continental deposits. Sixty-four oriented rock samples were collected for a magnetostratigraphic study along a 92 meters thick section including the fossiliferous layer. Rock magnetic investigations indicate the presence of both high and low coercivity minerals. Specimens subjected to progressive thermal demagnetization procedures show that the samples exhibit a high temperature magnetization component and display a normal polarity. Based on biostratigraphic constraints, the Guetaf section is correlated with Chron C4An, indicating an age ranging from
9.1 to 8.7 Myr.
  

Based on material found in about 15 localities the relationships of the genera Microparamys and Glirarus have been studied. One new genus, two subgenera and three species [Microparamys (Sparnacomys) chandoni n. subgen. and n. sp., Microparamys (Pantrogna) russelli n. subgen., Eoglirarus wildi n. gen. and n. sp., Gliravus meridionalis n. sp.] as well as the publication
of numerous new facts concerning species previously reported, support the phyletic scheme proposed. The latter shows that the origin of the Gliravinae is to be sought among the very small and still rather poorly known Microparamys species of the early Eocene. Gliravus: robiacensis can be considered as the common ancestor to different lineages not only of Glirarus but also of modern genera (Peridyromys, Glirudinus and Microdyromyx), at the origin of which Peridyromys micio, although difficult  to interpret, occupies a similar place.

The stratigraphic conclusions permit more detail in the chronologie succession of the localities studied. The paleoecologic and biogeographic aspects lead one to the problem of the oligocene "Grande Coupure" through the study of this group.

  

Le Mémoire Extraordinaire 1988 de PALAEOVERTEBRATA regroupe dix articles consacrés au gisement à mammifères du Miocène supérieur de Montredon (Hérault), connu et classique depuis la fin du siècle dernier, et auquel est lié le nom du savant paléontologue lyonnais Charles Depéret.
Cette monographie vient normalement à la suite de celle parue en 1982 dans PALAEOVERTEBRATA, dont les différents articles traitaient de la stratigraphie du gisement, et faisaient l'étude des différents groupes de micromammifères représentés dans la faune (insectivores, chiroptères, rongeurs). 

The genus Cryptomeryx SCHLOSSER, 1886, inusited during a long period, has been discovered in Lower and Middle Oligocene localities of the Quercy region (South-West France). This new material, as well as specimens from the old collections referred to Cryptomeryx, are described; their study, allows us precising the definition of the genus, and confirming its allocation to the Tragulidae family. The type species of the genus, Crypmmeryx gaudryi (= Lophiomeryx gaudryi FILHOL, 1877), occurs in several localities at the base of the Middle Oligocene (Itardies, La Plante 2, Roqueprune 2, Soulce, Herrlingen 1). The new species C. matsoui n. sp. has been defined in the older locality of Mas de Got (top of Lower Oligocene). It is possible that the species Pseudamphimeryx decedens STEHLIN, 1910 pertains to the same genus. Also to the Tragulids must be referred the monospecific genus Iberomeryx (I. parvus GABOUNIA, 1964) from Upper Oligocene of Benara (Georgie, URSS), with which Cryptomeryx is related. These genera are not direct ancestors of Miocene tragulids; their occurrence in the Western European Oligocene results from a first immigration wawe of the family. These Tragulids are one of the most archaic groups of Ruminants. They are probably derived from a primitive stock which had acquired in Asia the selenodont condition of the dentition. 

Paleosols and the taphonomy of vertebrate fossils in the Eocene Kuldana Formation of northern Pakistan provide important information on the preservation and time-averaging of fossil assemblages. Morphologic, mineralogic, and chemical data as well as comparisons with Quaternary soils suggest that Kuldana paleosols formed under generally dry and oxidizing conditions over time intervals of less than 100 000 years and perhaps as short as 1000 years. The distribution of carbonate in Kuldana paleosols further indicates that the upper half of the profiles were acidic whereas the lower halves were alkaline. Vertebrate fossils are rare in Kuldana paleosols and occur primarily in well-cemented sandstones and conglomerates with abundant micritic and iron-stained nodules that were reworked from floodplain soils. The scarcity of vertebrate remains in Kuldana paleosols probably reflects a combination of acidic, dry, and oxidizing conditions in the upper half of the profiles and rapid floodplain sedimentation. Comparisons between the taphonomic characteristics of Kuldana channel fossil assemblages and bone accumulations in modem rivers provide a basis for estimating the length of time represented by Kuldana fossils from several important localities. Vertebrate fossil assemblages from Barbora Banda are characterized by a low-diversity paleofauna, partially articulated skeletons, and bones that are sorted by size and shape. Comparison with bone accumulations in modern rivers suggests that the fossils from Barbora Banda accumulated in 1 to 10 years. Vertebrate fossils from the Lower Kuldana in the Kala Chitta Hills region, typified by locality H-GSP 62, are characterized by a high-diversity paleofauna and generally random and unsorted fossil bone distributions, which suggest that the fossils from these localities represent longer time intervals than the Barbora Banda fossils. Based on the time estimates for Kuldana paleosol development, fossil assemblages in Kuldana channel deposits in the Kala Chitta Hills region probably represent time intervals of about 1000 years. 

A new Devonian vertebrste locality has been discovered in 1976 in the basal part of the Khush-Yeilagh Formation in the eastern Alborz Mountains of Iran. The fossils occur in a band one centimeter thick which is identifiable at other outcrops in the area. A preliminary study of the remains has yielded the following faunal list : Placodermata (Phlyctaeniida indet.. Groenlandaspididae indet.. Coccosteidae indet., Holonema sp., Ptyctodontida indet., Antiarcha indet., Bothriolepis cf. kwangtungensis), Elasmobranchii (Ctenacanthidae indet.), Acanthodii (Gyracanthus sp., « Onchus » overathensis, Ischnacanthiforme indet.), Dipnoi (? Dipteridae indet.), « Crossopterygii ›› (Onychodus cf. sigmoides, Holoptychiidae indet., Osteolepididae indet.). This fauna is older than the Middle Givetian and probably of Middle or Lower Eifelian age. Owing to its diversity, it may prove possible to use it in the future as a reference fauna for the study of the Devonian vertebrates in Central Asia and the Middle East. 

The tooth morphology of the Thalattosuchia (marine crocodilians from the Jurassic and the Early Cretaceous) is analysed. The Callovian from Poitou and the Kimmeridgian from Quercy have yielded many remains of Metriorhynchus, Steneosaurus and Machimosaurus. These remains allow us to study the variations of tooth morphology during ontogenic growth, tooth replacement and the location of the teeth. We have defined different tooth types for these genera. In Metriorhynchus, the two tooth types defined do not coincide with the two groups recognized in the Callovian (broad-skulled and narrow-skulled metriorhynchids) but reflect the prey preferences of these forms. In Steneosaurus and Machimosaurus the five tooth types deñned are in agreement with the main taxa known from the Bathonian to the Early Cretaceous. This study allows to precise the function and the prey preference of the Thalattosuchia during the Jurassic and the Early Cretaceous.

  

The rodent fauna of Beni-Mellal is characterized by the abundance of ctenodactylids and cricetids. The latter are represented by four distinct species, among which a new form. Dakkamys zaiani nov. gen., nov. sp. is described. A detailed morphological analysis shows that, contrary to that which had been established before, « Cricetodon ›› atlasi Lavocat, 1961, is not closely related to any European form known; this species is attributed, in consequence, to the new genus Mellalomys. A simple biometric analysis has shown that the genus Myocricetodon Lavocat, 1952, is represented in this locality by two distinct species. The systematic homogeneity of the Beni-Mellal cricetids is also demonstrated: they can, as a matter of fact, all be referred to the subfamily Myocricetodontinae. The definition of this subfamily is completed. The sciurids and glirids are also reviewed in the light of new systematic and biogeographic information established ln Europe. A new species of Atlantoxevus from the early Pleistocene of Morocco, A. huvelini nov. sp., is described. It is probably the descendant of A. tadlae from Beni-Mellal. Biogeographic analysis leads one to consider this fauna as the result of geographic isolation in the Maghreb since the late Oligocene or the early Miocene. In particular no direct European influence can be discerned. Stratigraphic considerations resulting from the discovery of new localities in North Africa lead to the confirmation of the ante-Vallesian age of this fauna and to its parallelism with the faunas of La Grive in Western Europe and Fort Ternan in East Africa. The peculiar geologic nature of this locality is discussed.