The knowledge of the Anchilophini has been lately renewed by the discovery of a rather large amount of new material still largely unpublished. This new material offers the opportunity of a systematic revision of this tribe gathering those of European Eocene Equoidea which bear no mesostyle on upper check teeth and display a heavy trend to the molarization of premolars.

A cladistic analysis has made out two genera, Anchilophus (Paranchilophus included as a subgenus), characterized by a marked lophodonty and the transverse narrowness of the cheek teeth, a rather high hypsodonty, the frequent occurrence of "crochets" and "anticrochets" on the superior ones, and a rather weak molarization of the premolars, opposite to Metanchilophus n. gen. whose cheek teeth are more transversally elongated, less high, less lophodont, with cusps better distinct, enamel thicker and premolars more molarized on the whole.

Three species of Anchilophus are recognized, A. desmaresti, type species of the genus, A. (Paranchilophus) remyi and A. (Paranchilophus) jeanteli n. sp.

The genus Metanchilophus is more diversified with the species dumasi, radegondensis, gaudini (whose a new sub-species M. g. fontensis is defined), depereli, castrensis n. sp. and chaubeti n. sp.

The skull anatomy has been moreover described with several taxa; it brings to light (for all that one can generalize) that Anchilophini were light animals with a slender and elongated snout, a thin zygomatic arch, a rather developed encephalon with an advanced gyrencephaly.

The structure of the nasal opening together with the occurrence of epitympanic sinuses and the molarizing process of the premolars corroborate the attribution of this tribe to the family PalaeotheIiidae. 

Amongst a collection of selachian teeth made at Hoegaarden in a marine level of Bruxellian (Lutetian) age, containing a reworked Landenian (Sparnacian) fauna mixed with a contemporaneous one, a few teeth of  terrestrial mammals have been discovered. They comprise two rare European taxa: ? Hallensia sp. and Palaeonictis gigantea, both known from the Landenian. Even though the ?Hallensia has not been definitely identified, il differs from the only perissodactyl of this age previously recorded from Belgium (Cymbalophus cuniculus). 

The first good skeletal remains of Homogalax protapirinus from the Wasatchian of the Bighorn Basin, Wyoming, indicate that this primitive tapiromorph was more plesiomorphic in many features than primitive equoids including Hyracotherium. Compared to Hyracotherium, Homogalax more closely resembles Phenacodonta (the closest outgroup of Perissodactyla for which postcrania are known) in various details of articular surfaces, muscle attachments, and proportions of the humerus, manus, and pes.Among known taxa, Homogalax most nearly approximates the plesiomorphic postcranial skeletal anatomy of Perissodactyla. 

The discovery in the Turolian (Late Miocene) of Dytiko 3 (Macedonia, Greece) of a complete skull with mandibles and cervical vertebrae, atlas and epistropheus, is a very important contribution to the knowledge of the subfarnily Chalicotheríinae. After the description, the comparison with other specimens of Miocene chalicotheres permits the revival of the generic name Macrotherium with a new species M. macedonicum. This genus is mainly characterized by a short snout and an inflated cerebral skull. It coexists during the Miocene with Chalicotherium. A cladistic analysis leads to conclusion that the species which has been described from the Early Middle Miocene of Rusinga must be identified as the type-species of a new genus: Butleria.





  

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.

  

    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. 

Equus caballus antunesi, nova subspecies, was a hypsodont, slender, and rather small horse (around 141cm at the withers), with narrow hooves and protocones longer on P3/-P4/ than on M1/-M2/. It does not fit in any of the different "types" of Pleistocene caballine horses previously recognized but may be related to the horse from the Acheulean of Solana del Zamborino.
Hypsodonty, small size, slenderness, narrow hooves are all characters that can easily be related to ecological conditions. Equus caballus antunesi was probably a horse adapted to rather dry and cold conditions and to a hard ground. It does not seem related at all to the North-European Equus caballus germanicus-gallicus group. 

Revision of the hipparion material from Montredon, including newly excavated and other unpublished specimens brings evidence of specific heterogeneity.
A fragmentary very small MC III seems very close to H. macedonicum from the upper Vallesian of Ravin de la Pluie, Greece. In that same site was also found a large hipparion.
Most of the Montredon material is referred to H. depereti. This species associates characters usually found in Vallesian hipparions (highly plicated upper cheek teeth, deep vestíbular grooves on the lower cheek teeth, robust metapodials) with characters more frequent in Turolian forms (middle size, lack of confluence in the upper premolar fossettes, lack of ectostylids on the adult lower cheek teeth, well developped keel on the MC III, facette for the 2nd cuneiform present on all MT III). H. depereti shares some of these characters with the Spanish and Portuguese hipparions transítional between the Vallesian and the Turolian (Masia del Barbo, Azambujeira) but is not identícal to any of them. The upper Vallesian hipparion material from Diavata, Greece, probably belongs to H. depereti but not the large hipparion rests from Ravin de la Pluie.
Thus, Montredon and Ravin de la Pluie may well share the same small species, H. macedonicum, but they differ in the associated one: middle-sized H. depereti at Montredon, large-sized H. primigenium at Ravin de la Pluie. Both sites, however, give evidence of small hipparions during the Vallesian, coexisting with other larger species.
The present paper also proposes an adaptation of the Kiesewalter's indices that calculates the height at the withers using the metapodial length, and discusses indices proposed by Gromova and by Sen et al. to express the relative development of the metapodial keel. 

The dentitions as well as one complete and several partial skeletons of Equoids from the Eocene lignite beds of the Geiseltal locality are revised. Instead of 13 species distinguished up to now 3 chronoclines with 5 species and 3 separate species are recognized (text. fig. 1). Propalaeotherium hassiacum HAUPT, 1925 is evolving into Propalaeotherium isselanum (CUVIER, 1824) between the levels of the « obere Unterkohle ›› and the « untere Mittelkohle ›› of the Geiseltal section. Propalaeotherium argentonicum GERVAIS, 1849 is shown to be present in the « untere Unterkohle ››, whereas Lophiotherium pygmaeum (DEPERET,1901) occurs in the « obere Mittelkohle ›› and in the « oberes Hauptmittel ››. Plagiolophus cartieri STEHLIN, 1904 appears during the transition from the « Mittelkohle ›› into the « Oberkohle ›› as the earliest true Palaeothere. Therefore the « Oberkohle ›› is already regarded as Upper Eocene. This is corroborated by the occurrence of a phyletic descendant of Propalaeatherium parvulum (Propalaeotherium n.sp.) in the middle and upper "Oberkohle " because this species appears otherwise for the first time at the mammal level of Lissieu. On the other hand Propachynolophus gaudryz (LEMOINE, 1878) described by Matthes (1977) from the « untere Unterkohle ›› turns out te be in fact a Phenacodont. Thus the decisive argument for classifying the « untere Unterkohle ›› as Lower Eocene has to be dropped. Biostratigraphically the « Unterkohle ›› and the «Basishauptrnittel ›› correspond with the lower Middle Eocene (mammal level of Messel), whereas the «unteres Hauptmittel ›› and the « untere Mittelkohle ›› are equivalent to the middle part of the middle Eocene (mammal level of lssel), and the « obere Mittelkohle ›› together with the « oberes Hauptmittel ›› coincide with the upper Middle Eocene (mammal level of Bouxwiller). 

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. 

The locality of Fons 1, one of the fossiliferous outcrops in the late Eocene limestones of Fons-outre-Gardon (Gard), has yielded varied remains of mammals. The specimens were prepared by dilute acetic acid attack on the rock and by impregnation with an acrylic resin.
This fauna, rich with about 20 species, can be included in the biochronologic zone of Euzet. The Palaeotheridae (sensu Simpson 1945), represented by 6 species, occupy a predominant place; Plagiolophus annectens is particularly abundant, comprising 55% of all the specimens found.
The abundance of this species has permitted a detailed comparative study with the corresponding form from Euzet. The quantitative tests brought out a slight but highly sígnificant difference between the average dimensions of the teeth in the two populations. Moreover and in spite of the feeble rate of evolution in the Plagialophus dentition, diverse archaic particularities can be seen which permit the conclusion that the form from Fons 1 is a little the older. This conclusion is corroborated by observations on the other palaeotherids, particularly Lophiotherium aff. cervulum, whose dental evolutionary stage is intermediate between those of the corresponding forms known from Robiac and Euzet.
A new species of Pachynolophus is described, P. garimondi n.sp., the last representative known of the genus. lts teeth are distinguished by their size, a great heterodonty, and the weakness
of their cingula.