The study of endocasts, or casts of the endocranial space, have played an important role in shaping understanding of mammalian, and particularly primate, brain evolution. Recently, the reconstructions of three-dimensional virtual endocasts from high-resolution computed tomography images have allowed for the visualization and quantification of endocasts in several Paleocene and Eocene primate species. Here we present the virtual endocast of MaPhQ 289 (informally known as the Montauban 9 skull), a specimen of Necrolemur antiquus Filhol 1873, a middle to late Eocene European primate of the family Microchoeridae. The virtual endocast of MaPhQ 289 reveals a lissencephalic surface morphology with expanded temporal poles and minimal overlap of the cerebellum or olfactory bulb by the cerebrum, which closely resembles the morphology of the endocast of its contemporary relative, Microchoerus erinaceus (Primates, Microchoeridae). MaPhQ 289 yields an endocranial volume (ECV) of 2.36 cm3, about 60% smaller than the volume of the most commonly cited ECV of N. antiquus. Thus, the size of the brain of N. antiquus relative to its body size is likely to be smaller than has been reported in previous literature, highlighting the importance of corroborating older ECV estimates with new evidence using 3-D imaging techniques. 

A short review of the genera and species of snakes from the Quercy's phosphorites described by former authors is followed by the study of specimens recently collected. Most of these latter specimens belong to the Aniliidae, Boidae, Colubridae and to the Scolecophidia; the precise systematic position of some of them is not defined yet. The following genera and species are described: Eonilius europae nov. gen. and nov. sp., Platyspondylia lepta nov. gen. and nov. sp., Coluber cadurci nov. sp. and Dunnophis cadurcensis nov.  sp.; a species described by de Rochebrune (Palaeopython filholi) is revised. One of the most important conclusions of this study is that the Colubridae appear as early as the Upper Eocene. The stratigraphic repartition of these snakes shows that the rich Upper Eocene fauna is followed by the very reduced fauna of the Lower Oligocene; then the oligocene «Grande Coupure» corresponds to a very important faunistic renewal. The fauna remains poor and little diversified during the beginning of the Middle Oligocene after which there is a new faunistic explosion. 

Three new fossiliferous localities, two of karstic origin, Castelnou 3 and Font Estramar, respectively Late Upper Miocene and Lower Pliocene, and one of lacustrine origin, Thuir, Lower Pliocene, add data about the transition between Miocene and Pliocene faunas of rodents in southern France. An unexpected association of taxa was present in the late Upper Miocene, including between others, Myocricetodon, Hispanomys, Ruscinomys, Cricetus barrierei, Promimomys and a new species of Stephanomys, S. dubari nov. sp. Myocricetodon is still known in the Lower Pliocene. It is shown that the large field-mice known since the Late Upper Miocene belong to two different lineages, on one side, A. jeanteti, on the other side, A. gudrunae followed by A. gorafensis. Biochronological and biogeographical implications are discussed. 

New and hitherto unpublished mammals from the stratigraphical levels Unterkohle, Untere Mittelkohle and Obere Mittelkohle of the Geiseltal near Halle, GDR, are described (= biochronological levels MP 11-13, Geiseltalian sensu Franzen & Haubold 1986a, b). The marsupial taxa Amphiperatherium aff. maximum (MP 12), A. goethei (MP 12), and Peratherium aff. monspeliense (MP 12 and 13) are recorded for the first time. A lectotype for Amphiperatherium giselense is designated, and the alleged primate Microtarsioides voigzi is assigned to Marsupialia, incertae sedis. A new insectivore species, Saturninia ceciliensis n. sp., is described (MP 13). The anteater Eurotamandua joresi is recorded for the first time outside its type locality, Grube Messel, FRG (MP 11). The present humerus and ulna display the autapomorphic features of the myrmecophagids. 

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 rodents (Cricetidae, Gliridae, Sciuridae) found in lacustrine, brackish marine and karstic sediments of Miocene age in Languedoc, assign the position of the different localities in the scale of "niveaux repères" used by mammalogists. Some detailed stratigraphical studies bring several correlations between this continental biochronological scale and the marine scale ; the most important results are the Aquitanian age of the "niveaux repères" of Coderet and Paulhiac, the Burdigalian age of Laugnac, Estrepouy, Vieux-Collonges, La Romieu and Sansan and the Langhian or Lower Serravallian age of La Grive M. The correlations between the Tethys and the Central Paratethys for the Lower Neogene profit also of these results, since the locality of Neudorf Spalte 1, 2 (Czechoslovakia) is shown to be younger than Sansan (France). The paleontological study has also several geological inferences for the Miocene of Languedoc ; with the calibration of this Miocene, we know quite precisely that the Lower Miocene is chiefly a time lacustrine sedimentation, and also that the marine Miocene sedimentation ends early in the Miocene Period, in Langhian or lower Serravallian times. 

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). 

The description of new material from three classic middle Eocene localities of western Europe permits the addition of details to the systematics of primitive Pseudosciurids. The cranial anatomy of Protadelomys cartieri (STEHLIN and SCHAUB) from Egerkingen is described here and compared to that of the Adelomyines from the late Eocene, until now the only ones known. The morphologic and biometric study of the dentition of P. cartieri compared to that of P. alsaticus n. sp. from Bouxwiller and P. Iugdunensis n. sp. from Lissieu, forms respectively older and younger than P. cartieri, permits the evolutionary tendencies of the group to be demonstrated and shows that notable differences in age exist between these localities. This ensemble of forms can constitute a valuable guide lineage in the establishment of a fine stratigraphy of the period. Other less well known lineages are present at Egerkingen along with P. cartieri. They can be related to genera that have been noted int he late Eocene. In conclusion, a criticism of recent zonation proposals, made by divers authors, completes this article. 

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. 

The faunal list of the mammals collected at the locality of Aumelas (Hérault, France) is revised. For the first
time this Middle Eocene locality is precisely settled in the european chronological scale of "niveaux repères", between the levels of Bouxwiller and Egerkingen, in Uppermost Lutetian.
A new Dichobunid from the site is described : Aumelasia gabineaudi n. g., n. sp. This new genus has primitive characters. and it may be in the descent of the Lower Eocene Protodichobune. 

A late Pleistocene deposit of 60 species of vertebrates and 12 of invertebrates is described from Robinson Cave, Overton County, Tennessee, U.S.A. Forty-eight species of mammals are represented by at least 2,483 individuals; 10 % are extinct, 10 % occur in the state only as boreal relicts in the Great Smoky Mountains; 23 % no longer occur as far south as Tennessee; 57 % occur at or near the site today. Nínety-one percent of the Recent mammal species can be found living today in the Minnesota-Wisconsin area, approximately 10 degrees farther north. Fluorine analysis suggests a long period of accumulation. The following 10 mammalian species are recorded from Tennessee for the first time. Sorex arcticus, Microsorex hoyi, Citellus tridecemlineatus, Clethrionomys gapperi, Microtus pennsylvanicus, Synaptomys cooperi, Synaptomys borealis, Zapus nudsonius, Napaeozapus insignis, Martes americana. Six additional species are present as boreal relicts in the Great Smoky Mountains of eastern Tennessee but not at the site today : Sorex cinereus, Sorex dispar, Sorex palustris, Parascalops breweri, Glaucomys sabrinus, Mustela nivalis. Six forms are extinct: Canis dirus, Ursus americanus amplidens, Sangamona furtiva, Dasypus bellus, Mammut americanus,Megalonyx jeffersoni. Twenty-six additional species of mammals, all of the snails, birds, reptiles, and amphibians recovered from the fauna still inhabit the area today: The fauna is indicative of a cold-temperate climatic episode associated with the Wisconsin glaciation, but may be chronologically mixed. 

Two new Squalicorax species, S. benguerirensis nov. sp. and S. microserratus nov. sp. are described from the Lower Maastrichtian of the Benguérir phosphate open mine, Ganntour deposit, Morocco. The species S. benguerirensis nov. sp. was classically assigned to S. yangaensis since Arambourg (1952) and has been also recognized in coeval deposits from eastern USA to Mid-East. The species S. microserratus nov. sp. correspond to the lateral teeth of S. kaupi as reported by Arambourg (1952) and which is now referred in fact to S. bassanii. The comparison of these two new species with other Anacoracids, known in Moroccan or elsewhere, allows highlighting the great taxonomic and ecological diversities of this family during the Cretaceous.
  

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. 

The mammalian fauna of the Tagai locality of Olhon Island in Lake Baikal contains six artiodactyls:
Amphitragulus boulangeri, Lagomeryx parvulus, Stephanocemas sp., Palaeomeryx kaupi, Orygotherium aff. escheri, and Brachyodus intermedius. They are reported from Eastern Siberia for the first time. A description of teeth and limb-bones are given. An analysis of the systematic composition of the Tagai fauna allows it to be correlated with European faunas of the second part of the Early Miocene (Orleanian, MN 3-4) and permit suggestion of the existance of a united European-Siberian zoogeographical sub-area in the middle latitudes of Eurasia at that time. 

The genus Pachynolophus, one of the poorest known of the Palaeotheriidae, includes the brachyodont forms with reduced and non-molariform premolars and with upper molars lacking a mesostyle. Quantitative characters (divers surface indications and elongation of the teeth), while demonstrating a close relationship to Hyracotherium, permit a better differentiation of the genus, confirm its specific splitting, and permit the distinction of three lineages. The skull from Memerlein is taken as the type of a new species, P. Iavocati, of which the dentition is extremely characterized by its lophiodonty, the strong reduction of the premolars and the reduction of the cingula. This characterization testifies to a late age which extends the existence of the genus quite near to the Eocene-Oligocene limit. Compared with the only two skulls known of related species (Hyracotheríum vulpiceps and Pachynolophus Iivinierensis), that from Memerlein is distinguished by progressive characters affecting diferent regions but most particularly the braincase; it is not possible, however, to isolate within this evolution the part which leads to a systematic differentiation. Modernization is translated by a considerable increase in size of the braincase, principally in the frontal region, a development of the facial region with anterior displacement of the dental series and a greater specialization of the masticatory apparatus. This evolution parallels the history of the Equidae of the North American early Tertiary, but certain particularities, the form of the alisphenoid, the presence of an anterior frontal foramen, and the structure of the paroccipital apophysis, testifies to the independance of the European forms. 

Abstract: Paleontological exploration in the Turkana Basin near Ileret, Kenya yielded the most complete adult elephant cranium (KNM-ER 63642) known from the late Miocene to mid-Pliocene. KNM-ER 63642 derives from the lower Lonyumun Mb. of the Koobi Fora Fm. and dates to the early Pliocene, >4.3 Ma. The cranium is immense in size and preserves most of its structures including left and right M2-3, permitting its comprehensive comparative study and secure taxonomic assignment to Loxodonta adaurora. Features distinctive of the species and exhibited by KNM-ER 63642 include very elongate, divergent tusk alveoli, a short, biconvex cranial roof, anterosuperior angulation of the occipital planum, non-inflated occipital planum and absence of supralateral parietal "bossing," broad, flat premaxillary nasal processes, broad, laterally downturned nasal aperture superior to the level of the orbits, and M3s with wide, subhypsodont plates that are parallel-faced and separated by U-shaped transverse valleys. The M3s also exhibit characteristic L. adaurora traits of greatest width at their bases, rounded cross-sectional shape, thick enamel, abundant cementum, and strong anterior and posterior accessory conules. Of extant taxa, KNM-ER 63642 most closely resembles crania of African elephants. Its inclusion in the Loxodonta clade is tenuous, however, because shared features are either symplesiomorphic or are difficult to test for synapomorphy due to the poor fossil record of crania of late Miocene-early Pliocene elephants. Overall, the cranial morphology of KNM-ER 63642 is unexpectedly advanced for an elephant of its antiquity. Its anteroposterior compression and height are concordant with efficient proal masticatory action, indicating that by the early Pliocene L. adaurora evolved craniodental adaptations in phase with feeding preference for C4 grasses. The advantage of synchrony of morphology and behavior is reflected by the dominance of the species in the greater Turkana Basin during that interval.
  

The remains of Ruminantia are very rare at Montredon. No specific determination was possible. We have only one Micromeryx, one small cervid, one tragocere and one (?) gazella. The faunal spectrum is in good correlation with the general retreat of the cervids in the European upper Miocene, but in contrast it is not convenient for the bovids, which are in expansion at the same time. For them, we have to invoke the local ecological conditions.
  

The revision of the Rhombodontidae from the Maastrichtian of Morocco led us to the description of a new species: Rhombodus andriesi.

The biometrical study of populations of R. binkhorsti and R. microdon, species sometimes considered as synonymous, supports the conclusion that they represent two distinct species and not young and adult specimens of a single species. The stratigraphical range of these two species confirms this
result.

The reexarnination of type-series studied by C. Ararnbourg led us to revise the generic status of Rhombodus bondoni which is now ranged, because his dental features, in the new genus Dasyrhombodus showing a less derived dentition than Rhombodus. The stratigraphical range of each species is clarified within the phosphatic series. 

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 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.