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. 

Two new species, Omanodon minor n. g., n. sp. and Shizarodon dhofarensis n. g., n. sp., known from fifteen isolated teeth, are described here as the first adapiform primates (?Anchomomyini) recognizable to date in the Taqah material (early Oligocene of Sultanate of Oman).

Omanodon minor n. g., n. sp. displays special morphological similarity to the adapid tribe Anchomomyini from the Eocene of Europe, and especially to the Anchomomys lineage. Resemblances with the extant lemurifonn Microcebus are also noticeable and could be regarded as supporting Schwartz & Tattersall (1983) hypothesis of special relationships between the anchomomyine adapids and the cheirogaleid lemuriformes. However, these morphological affmities can be interpreted, altematively, as the results of parallelisms: important differences in upper molars indicate that the resemblances of cheirogaleids and Omanodon minor n. g., n. sp. are indeed probably due to parallelisms. Phyletic relationship of O. minor n. g., n. sp. to Anchomomyini is finally the most likely hypothesis.

Shizarodon dhofarensis n. g., n. sp., although much more poorly known, is closely related to Omanodon minor n. g., n. sp., at least at a familial level. The general morphology of this species suggests
also a close link with adapid Anchomomyini, although precise relationships within this tribe remain obscure. Interesting resemblances of Shizarodon dhofarensis n. g., n. sp. to Djebelemur martinezi lower molars (early Eocene of Tunisia) are also noticeable. These resemblances are even stronger than those betwen Omanodon minor and Djebelemur martinezi. However the very bunodont upper molars referred to D. martinezi are unusual for adapids, and there are moreover some notable differences in their lower molars. Thus resemblances in Djebelemur and Shizarodon are probably due to paralellisms.

Because of the fragmentary nature of the material and of possible parallelisms, the systematic position of Omanodon and Shizarodon within adapiformes cannot however yet be established definitively. 

Avec ce volume se clôture l'étude géologique et paléontologique des sites à hominidés de Koobi Fora. Il fait suite aux deux précédents ouvrages, parus respectivement en 1978 et 1983, consacrés également à l'étude des faunes recueillies sur ces gisements dans le cadre du Koobi Fora Research Project. 

L'ouvrage est divisé en trois grandes parties traitant successivement: I. l'anatomie ("Proboscidean flesh and bones"), en abordant la taxonomie, l'allure générale et l'éco-éthologie des proboscidiens actuels et fossiles; II. les causes de mortalité collective naturelle et provoquée chez les actuels; III. les documents fossiles et l'extinction des formes anciennes d'Amérique du Nord. 

The fauna from three new rodent localities (Castelmaurou, Grépiac-carrière et Grépiac-rive gauche) from Oligo-Miocene molasses of the Toulouse area is described. The one from Colomiers is completed. 11 species belonging to 4 families (Cricetidae, Eomyidae, Gliridae, Sciuridae) are present. The Miocene localities of Grépiac-carrière and Colomiers are correlated with Balizac, La Brète, Lambert and Lespignan. Grépiac-rive gauche is just a little older than these sites. Castelmaurou is somewhat younger than La Milloque and belongs to Oligocene. 

Simpson (1937a) reconstructed the brain of the Paleocene multituberculate Ptilodus as having the olfactory bulbs widest anteriorly, an unusual condition among mammals. Slight preparation and reexamination of the endocast specimens of Ptilodus reveals that the olfactory bulbs in fact taper anteriorly, as in the recently-described endocranial casts of three multituberculate species from the Late Cretaceous of Asia, and as in those of other mammals. The brain of Ptilodus was therefore essentially of the same general pattem as in other multituberculates. Ptilodus differs, however, in having the vermis more deeply inserted between the cerebral hemispheres. Other details concerning the endocast morphology of Ptilodus are clarified.

The encephalization quotient (EQ) of Ptilodus is recalculated from revised estimates of both endocranial volume and body mass to fall somewhere within a broad range of values; from 0.41 to 0.62 if the olfactory bulbs are included and from 0.37 to 0.55 if they are not. In any case, the relative brain size of Ptilodus is roughly equivalent to that of Chulsanbaatar, the only other multituberculate for which EQ has been calculated, but considerably smaller than that of an average extant mammnal. 

The two species of Sandgrouse from Quercy, Pterocles validus MILNE-EDWARDS and P. larvatus MILNE-EDWARDS, are ascribed to the genus Archaeoganga MOURER-CI-IAUVIRÉ which includes a third, very large species, A. pinguis. The sandgrouse of Saint-Gérand-le-Puy, Pterocles sepultus MILNE-EDWARDS, is ascribed to a new genus, Lepzoganga. This form appears in the Upper Oligocene of Quercy, in Pech Desse and Pech du Fraysse localities, and is still present in the Lower Miocene of Saint-Gérand-le-Puy and Paulhiac. Recent sandgrouse live in semidesert or desert areas. The indications provided by mammal and bird faunas in the localities where sandgrouse were found, confirm that the paleoenvironment was open and arid. The morphological study of these fossils indicates that, in the Upper Eocene, the Pteroclidae were already completely individualized with respect to Charadriiformes.
  

The composition of assemblages of lizards and Amphisbaenian from the European Eocene are described. At least ten lizard families are identified from the lower European Eocene levels. Eight are still recorded in the last level (Escamps) of the late Eocene. Agamid lizards (genus Tinosaurus) died out by the end of the lower Eocene and Varanid lizards (genus Saniwa) disappeared by the beginning of the late Eocene. Amphisbaenians are recorded throughout the Eocene in Europe. The lacertilian fossil record of Europe and North America show a high degree of faunal resemblance in the early Eocene, followed by a decrease during the later part of the epoch. The lacertilian and amphisbaenian faunas from the European Eocene are not subject to great variations during the period; this is in contrast with the mammal record at the same time. It is argued that the low metabolic rates and the ectothermy of lizards could explain those differences, along with the increasing insularity of the West European area during the late Eocene time.

  

La taphonomie (science de l'enfouissement et de la fossilisation) des micromammifères a trop souvent été négligée par rapport à celle des grands mammifères. Or, pour expliquer les concentrations parfois très importantes de microfossiles dans les grottes et les sites préhistoriques il faut connaître les mécanismes qui concourrent actuellement à favoriser les accumulations de ces derniers. C'est le but de l'ouvrage de Peter Andrews qui se décompose en deux parties. 

A fossil species of the extant genus Leuconoe, L. lavocati n. sp. from Le Garouillas Oligocene locality, Quercy phosphorites, SW-France, is established in nomenclatural standards. 

 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. 

Enamel microstructure in the incisors of Old- and New World hystricognath rodents:

The incisor enamel microstructure in more than 100 genera of fossil and Recent hystricognath and sciurognath rodents was studied. A multiserial schmelzmuster is present in the Hystricognathi, the Ctenodactylidae, advanced Chapattimyidae, and in Pedetes. A redefinition of pauciserial and multiserial HSB is given that makes the two enamel types unambiguously distinguishable which apparently represent well defined evolutionary levels. In the pauciserial Schmelzmuster the IPM is thicker than in the multiserial one. In pauciserial HSB the IPM always surrounds each prism, and the crystallites of the IPM run parallel to prism direction; transition zones between HSB are lacking; the inclination of the HSB is normally very low and the prism cross sections are not flattened but somewhat irregular. The number of prisms per HSB is no good distinctive character for pauciserial and multiserial HSB, since there exists a wide overlap. The pauciserial schmelzmuster is primitive, the multiseiial derived because: 1. the pauciseiial schmelzmuster appears earlier in the fossil record in the most primitive rodents (Paramyids s.l. and Ctenodactyloids); 2. the Eocene Ctenodactyloidea show pauciserial HSB but the Oligocene and younger ones are characterized by multiserial HSB; 3. in the outgroup comparison, the Eurymylidae (Mixodontia) show pauciserial HSB; 4. biomechanically, multiserial HSB strenghten the enamel better than pauciserial HSB, since their IPM runs nearly always in an angle of 45° or more to the prisms.

In multiseríal HSB three subtypes can be distinguished which are differentiated by the IPM orientation. Primitive is a (rarely strict) parallel or acute angular, anastomozing IPM, and derived is an interrow sheet-like ("plattenartige") IPM. This evolutionary polarity is indicated by enamel evolution in the Ctenodactylidae which show an acute angular IPM in the Oligocene and a rectangular interrow sheet-like IPM since the Miocene. Among the Caviomorpha a rectangular interrow sheet-like IPM is restricted to the Octodontoidea; therefore they must be considered derived in terms of their enamel structure. The first multiserial HSB in rodent incisors appear in phiomyids or chapatrimyids from the Upper Eocene of Algeria. The IPM is acute angular and anastomozing. The worldwide next younger multiserial HSB are found in Lower Oligocene phiomyids of Fayum, Egypt There already a rectangular interrow sheet like IPM is present (in Metaphiomys) besides the acute angular anastomozing IPM.

The first Caviomorpha from the Deseadan (Oligocene-Miocene) likewise show already acute angular anastomozing IPM (e.g. Scozamys) and rectangular interrow sheet-like IPM (Platypittamys). Therefore the first Caviomorpha cannot be positioned close to a transition from pauciserial to multiserial HSB. In none of the potential caviomorph ancestors from southern North America multiserial HSB or transitional stage between pauciserial and multiserial HSB could be found. The similarities between the enamel types of the Fayum rodents and the rodents from the Deseadan of South America make a derivation of the Caviomorpha from Paleogene North African phiomorph rodents or their direct ancestors most probable. This supports at the same time a descent of the platyrrhine Primates from North African anthropoids.
  

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.

  

The recent discovery of several mandibular toothplates of a chimaeroid fish at a dig in the area of the Landover Mall, near Landover, Prince Georges County, Maryland, brings to our attention a new species of the chimaeroid, Ischyodus.
 Although superficially reminiscent of the European chimaeroid toothplates of Ischyodus thurmanni (cf. text-fig. 2), I. williamsae nov. sp. probably has a more closer relationship to I. bifurcatus CASE, 1978, of the Upper Cretaceous of New Jersey and Delaware. 

A well-preserved anterior cranium of Paranourosorex gigas RZEBIK-KOWALSKA, 1975 from Podlesice, Poland, provides additional knowledge of this rare shrew, including almost complete maxillary dentition. The systematic status of this species as a relative of recent Anourosorex MILNE-
EDWARDS, 1870 is confirmed 

    Two families are reviewed (Hyracodontidae and Rhinocerotidae) from the Paleogene of Mongolia. The following taxa are described from the former family:  Triplopus? mergenensis sp. nov., Prohyracodon meridionale CHOW, Prohyracodon? parvus sp. nov., Forstercooperia ergiliinensis GABUNIA & DASHZEVEG, Ardynia praecox MATTHEW & GRANGER, A. mongoliensis (BELIAYEVA), Ardynia sp., Urtinotheríum sp. (or Indricotherium) and Armania asiana GABUNIA & DASHZEVEG. All of them are from the Paleogene of the eastem Gobi Desert The hyracodontid Pataecops parvus RADINSKY is described from a new locality, Menkhen-Teg (Middle Eocene), in the Valley of Lakes.
    In the second family, a new species of Ronzotherium, R. orientale sp. nov. has been recognized from the Oligocene of Ergilin Dzo and Khoer Dzan of the eastem Gobi Desert. Ronzotherium sp. and Allacerops sp. have been described from the Oligocene of Khoer Dzan. The genus Ronzotherium, formerly known from the Oligocene of eastem Europe, has been reliably established in the Oligocene fauna of Mongolia. The genus Symphysorrachis BELIAYEVA, 1954, previously believed to be a junior synonym of Ronzotherium, is here resurrected.
    Descriptions are provided for key localities in the Eocene and Oligocene of Mongolia and the adjacent territories of northern China, containing fossil Hyracodontidae and Rhinocerotidae. In addition, the question of the Eocene-Oligocene boundary in these Mongolian and Chinese sections is discussed. Paleontological evidence has been used to correlate Eocene-Oligocene boundary layers in the eastem Gobi Desert (Mongolia) and Inner Mongolia (China). A brief discussion is provided on the phylogenetic affinities of the genera within the family Hyracodontidae. 

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. 

Editorial for celebrating the publication of the volume 20.

La revue PALEOVERTEBRATA a été fondée en 1967 par Louis THALER, à une époque où il n'existait, au plan international, que deux périodiques uniquement consacrés aux vertébrés fossiles. Actuellement ce nombre n'est que de quatre. A l'origine la revue fut essentiellement créée pour diffuser les résultats des chercheurs du Laboratoire de Paléontologie de l'Université de Montpellier, alors en début d'expansion et plusieurs thèses et de nombreux travaux directement liés à des thèses y furent publiés ce qui n'excluait déjà pas la publication d'articles d'auteurs étrangers.
[...] 

Mammal-bearing localities have been discovered in the marine and lacustrine series of the middle Ilerdian (Lowermost Eocene) from Southem France (Minervois and Corbières). In the localities of Fordones, Monze, Fournès, and La Gasque, thirty mammal species have been identified. Among others, they include ischyromyid rodents (Microparamys and Pseudoparamys), paromomyid and adapid primates (Arcius and Donrussellia), new insectivores, condylarths, and a dyspternine pantolestid. These faunas provide new informations on the early Eocene Mesogean faunas of Rians and Palette. The assemblages of primates and rodents from Fordones support good  correlations with Palette which was recently placed near the standard-level of Dormaal (MP 7). In fact, Palette and Fordones could be even older than Dormaal. Consequently, there seems to be a relatively important temporal gap between the late Paleocene of Cernay and the Sparnacian of Dormaal. This gap could be partly filled with the Mesogean faunas of Palette, Fordones, and Silveirinha. On the basis of these new mammal faunas the marine middle Ilerdian is proved to be older than the Cuisian stage of the Paris Basin. With regards to the position of the Fordones fauna at the top of the NP 10 calcareous nannoplankton biozone, the westem European paleomammalogists Paleocene/Eocene boundary could be situated between the NP 9 and NP 10 biozones. 

The dentition of Welcommia bodeuri nov. gen. nov. sp. from the Valanginian of Southem France is described and reconstructed. Species and genera of Upper Jurassic and Lower Cretaceous Hexanchiformes are reviewed and discussed.
The genus Notidanoides MAISEY, 1986 must be restricted to the single Nusplingen Upper Jurassic specimen, whose attribution to the species muensteri AGASSIZ, 1843 remains doubtful.
The genus Paranotidanus WARD &THIES, 1987 that does not rest on any type-species nor on any precise dental characterization must be rejected.
The genus Eonotidanus PFEIL, 1983, based on a very poorly preserved and heterogeneous type-material must also be rejected.
Teeth from the Lower Cretaceous, with a peculiar morphology, previously assigned to Eonotidanus or to Notidanoides, are to be ranked in the new genus Pachyhexanchus.