Tetraceratops insignis is known from a single, crushed skull from the Lower Permian of Texas. Its unique proportions and osteological details gained central meaning in the question of the origins of Therapsida since this early synapsid has been determined as the oldest and less derived therapsid. Apart from Tetraceratops, the ‘mammal-like’ Therapsida and their sister, the pelycosaur-grade Sphenacodontidae, are separated by one of the longest ghost lineages in tetrapod fossil record. However, the minor, though well justified critique faced insistent publication regarding the therapsid hypothesis. A carefull re-evaluation of the holotypic skull reveals that therapsid traits cannot be supported, including a rejection of the formerly supposed adductor shelf in the temporal fenestra. Increased understanding of ‘pelycosaur’ character variation underlines a haptodontine-grade or, less likely, sphenacodontid position for Tetraceratops. 

     The Faunas of Rodents from seven north-african fossiliferous beds distributed from the Middle up to the Uppest Miocene are studied. One genus, seventeen species, one subspecies described are new.
       A detailed description is given of the evolution of the numerous specific lines, systematic groups and communities. The evidence of the strong endemism of the North African faunas of that time compared with those of Europe as well as of Tropical Africa is clearly shown. Special relationships with Asia clearly also appear, mostly in the Middle Miocene and the beginning of the Upper Miocene.
       Using the specific lines with a biostratigraphic purpose gives the opportunity to establish a biochronological scale for the continental formations of the Maghreb. This scale is calibrated by a few absolute datations. These datations, as well as the stratigraphical study of several fossiliferous localities have given the possibility to establish precise correlations with the corresponding scales of Europe and of Tropical Africa, as well as with the marine formations of the Neogene of occidental Mediterranean sea.
       The paleoclimatic data connected with this period in North Africa are explained and the contribution of the micromammals is discussed. 

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. 

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). 

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. 

Several endemic deer remains from the Middle Pleistocene deposits of the Castiglione cave (Oletta, Haute-Corse) are examined here. A morphometric analysis allows to relate them to a new insular subspecies Cervus elaphus rossii. The bones were compared with those of the mainland early Middle Pleistocene subspecies Cervus elaphus acoronatus Beninde and the European species Cervus elaphus Linné (Late Middle Pleistocene and Upper Pleistocene forms (continental and insular)). The Castiglione fossil shows peculiar morphofunctional features in its appendicular skeleton suggesting a morphological convergence with certain Bovidae. 

The anatomy of Norselaspis glacialis n.g., n.sp., a primitive kiaeraspidian from the Lower Devonian of Spitsbergen, is described on the basis of spécimens studied by grinding sections or prepared with dilute formic acid. This study yielded some new anatomical details, including the presence of a canal prolonging posteromedially the canal alloted to the facial nerve by Stensiö. This posterior prolongation of the « facial canal ›› into the posterolateral part of the labyrinth cavity is consistent with the hypothesis put forward by Allis, Lindström, Jefferies and Whiting, that this canal housed the glossopharyngeus nerve. Furthermore, in N. glacialis, the foramen usually referred to as the foramen for the œsophagus opens posteriorly into a cavity in the postbranchial wall, referred to here as the intramural cavity, and which is interpreted as having housed the heart. Consequently, the œsophagus probably accompanied the dorsal aorta through the aortic canal. Finally, the foramen generally interpreted as having transmitted the ventral afferent arterial trunk is here considered as having housed the hepatic vein, which emptied into the venous sinus of the heart. The ventral afferent arterial trunk may thus have passed through the former «œsophageal ›› foramen.
The problem of the position of the dorsal nerves in the Osteostraci is discussed, and it is suggested that the three foremost nerve canals opening into the oralobranchial cavity housed the maxillary ramus of the trigeminus, the facial nerve and the glossopharyngeus nerve respectively. The mandibular ramus of the trigeminus must have accompanied one of the two foremost nerves, but for the moment it is impossible to decide which.
The problem of the nature of the interbranchial crests of the Osteostraci is briefly discussed. Comparison with the branchial apparatus of the Petromyzontida does not support the hypothesis that the interbranchial crests are part of the branchial arches, incorporated into the endoskeletal shield. A different hypothesis is proposed, that the branchial skeleton of the Osteostraci was situated entirely inside the oralobranchial cavity, and was attached to the endoskeletal shield only by the ventromedial processes. The grooves classically allotted to the efferent branchial arteries would thus have housed extrabranchial arteries, branching off from the dorsal aorta, and irrigating the ventral branchial musculature.
A phylogeny and a classification of the kiaeraspidians are proposed. The evolution of this monophyletic group is characterized by, e.g., reduction of cornual processes, shortening of the abdominal division of the shield, subdivision of the lateral fields, and enlargement of the supraoral fossae.
The phylogenetic position of the kiaeraspidians within the Osteostraci remains uncertain. Their sister-group may be either the benneviaspidiens or the thyestidians, or Thyestes alone (in which case they would have to be included within the thyestidians). 

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. 

The study of dental variations in Landenodon from Dormaal (early Eocene, Belgium) shows that only one
species is present in this locality : L. woutersi QUINET, 1968 (Condylarthra, Arctocyonidae, Arctocyoninae). A high morphological variability is described, especially concerning the metaconid of P/4, the paraconid of M/2, and some characters of M1/ which have been found to be independant of each other. This variability is discussed. 

The artiodactyls (Mammalia) from the latest Ypresian locality of Prémontré from the Paris Basin (niveau repère MP 10 in the lower Eocene of the Paris Basin) are described in this paper. Three species have been identified: 1) Diacodexis cf. varleti SUDRE et al., 1983; 2) a new species of Eurodexis ERFURT & SUDRE (E. russelli nov. sp.) defined after the revision of the species Messelobunodon? ceciliensis from the Lutetian beds of Geiseltal (Germany); and 3) Eurodexeinae indet., a probable ancestor of another form from the Geiseltal which was previously recorded as Homacodon? sp. (Erfurt 1993) and now named Parahexacodus germanicus. The two later forms are referred to the new subfamily Eurodexeinae (Erfurt & Sudre 1996). The analysis of these forms as weIl as comparative studies have led us to reconsider our previous conclusions regarding the content of the species Protodichobune oweni LEMOINE 1878 and some aspects of Ypresian diacodexid evolution. One can postulate that the divergence of E. russelli nov. sp. occurred during the first radiation of these primitive artiodactyls. Some other stem form with bunodont teeth such as Protodichobune and Aumelasia have also differentiated from Diacodexis. Like Eurodexis, these two genera persist during the middle Eocene. The absence of Protodichobune and Aumelasia at Prémontré is probably due to particular ecological conditions. 

A new genus and species of haplobunodontid artiodactyl, Hallebune krumbiegeli nov. gen. nov. sp., is described from the middle Eocene Geiseltal Fauna (Saxon-Anhalt, Germany). Its stratigraphic range is restricted to the MP 13 ("obere Mittelkohle") of the Geiseltalian. The material consists of seven fragments, representing both upper and lower jaws. It is indicated, that H. krumbiegeli was a small bunodont herbivore. The size and primitive character of the teeth suggest that the genus possibly is directly derived from Diacodexeidae.The new material forms the basis for reinterpreting the haplobunodontid phylogeny. 

A new Tertiary megadermatid is described from Rackham's Roost Site, a Pliocene limestone cave deposit on Riversleigh Station, northwestern Queensland, Australia. It appears to represent the first Australian record of Megaderma GEOFFROY, 1810, a genus otherwise known from Tertiary African and European taxa and the living Asian species M. spasma (LINNAEUS, 1758) and M. (Lyroderma) lyra PETERS, 1872. Megademza richardsi n. sp. is one of the smallest megademiatids known. It exhibits a mixture of plesiomorphic and autapomorphic features, the latter appearing to exclude it from being ancestral to any living megadermatid. The new species is one of eight megadermatids identified from the Australian fossil record, most of which are referable to Macroderma MILLER, 1906. 

Deux types de remaniements post mortem me paraissent caractéristiques de l'état de conservation des dents de mammifères fossiles dans les Phosphorites du Quercy :

1) Des destructions localisées d'origine biologique, sous forme de galeries de morphologie très variable creusées dans la dentine et le cément, et impliquant sans doute la participation de différents types de micro-organismes. Ces altérations se sont développées peu de temps après la mort, avant la fossilísation proprement dite et se sont rapidement arrêtées après l'enfouissement dans le sédiment phosphaté.

2) Des perturbations dans les structures de la dentine liées aux variations locales de minéralisation, provoquées par une imprégnation diffuse des zones les moins calcifiées par divers minéraux et probablement surtout de l`apatite. 

ATLAS OF MESOZOIC AND CENOZOIC COASTLINES, par Alan G. SMITH, David G. SMITH & Brian M. FUNNELL, 1995. Cambridge University Press, 99 p., 31 cartes, 3 tab!., 2 fig. ISBN 0-521-45155-8.

L' "Atlas of Mesozoic and Cenozoic coastlines" succède avec bonheur aux "Mesozoic and Cenozoic paleocontinental maps" de Smith & Briden, publié en 1977. 

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

The earliest cetaceans are found in the early Eocene of Indo-Pakistan. By the late middle to late Eocene, the group colonized most oceans of the planet. This late Eocene worldwide distribution clearly indicates that their dispersal took place during the middle Eocene (Lutetian). We report here the first discovery of a protocetid fossil from middle Eocene deposits of Senegal (West Africa). The Lutetian cetacean specimen from Senegal is a partial left innominate. Its overall form and proportions, particularly the well-formed lunate surface with a deep and narrow acetabular notch, and the complete absence of pachyostosis and osteosclerosis, mark it as a probable middle Eocene protocetid cetacean. Its size corresponds to the newly described Togocetus traversei from the Lutetian deposits of Togo. However, no innominate is known for the Togolese protocetid, which precludes any direct comparison between the two West African sites. The Senegalese innominate documents a new early occurrence of this marine group in West Africa and supports an early dispersal of these aquatic mammals by the middle Eocene.
  

Situated in the Cape region of the Republic of South Africa (RSA), the paleontological site of Langebaanweg is dated to 5.1 Myr and is famous for having yielded an abundant vertebrate assemblage, including numerous rodent species from the Mio-Pliocene transition. Based on molar morphology and skull anatomy, the single Gerbillinae taxon identified at Langebaanweg and described in this paper is allocated to Desmodillus, which is a modern monotypic South African endemic genus. It is significant in being the oldest representative of the genus in Africa. We describe here a new species of this genus which is larger than the modern D. auricularis, but nevertheless retains some of its main characteristics, namely the shape of the maxilla and mandible, the presence of poorly fused alternating cusps, and no longitudinal crest. This taxon differs from modern South African Gerbilliscus representatives in some mandibular and maxillary characters, in the m1 prelobe cusp, and in having less fused cusps. Two fossil Gerbillinae discovered in the Upper Miocene of Africa and Asia, Abudhabia and Protatera, have been compared with the new species. We discuss their relationships with modern and Plio-pleistocene Gerbillinae and conclude that Abudhabia could be the sister taxon of Desmodillus and that around 6-5 Myr a vicariance event allowed Gerbillinae to diversify into modern Desmodillus in South Africa, and Gerbilliscus in East Africa. The murine/gerbilline ratio, which is a good indicator of rainfall, supports other proxies which suggest that at 5.1 Myr the climate in the Langebaanweg region was more humid than today. 

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 strong lophodonty, an extreme heterodonty, some hypsodonty and regular overlayings of coronal cement are prominent features of the genus Leptolophus (Palaeotheriinae = Palaeotheriidae s.s.). The histological pattern of the teeth unusually joins type II enamel prisms, characteristic of advanced ungulates, together with archaic features, such as an almost complete lack of Hunter-Schreger zonation and a weak expanse of peritubular dentine. The skull is narrow and slender, with an elongated ante-orbital facial region, a moderately notched nasal aperture, a rather elongated post-canine diastem, parallel zygornatic arches and a fairly dorsally located squamoso-mandibular joint.The functional analysis brings to light "ectolophodont" masticatory cycles with two phases, in which maximum power was applied, contrary to equíds, on hindmost teeth; likewise, skull accomodations to increasing height of the teeth are quite different. This study leads to the assumption that Leptolophus may have been light mammals, living in rather open surroundings, browsing on herbaceous plants or leaves cropped close to the ground. Moreover, it appears that it could have been some inadequacy of dental structures to the dietary, which leaded to quick wear of the teeth and to many enamel notches, but had been somewhat balanced by the early increase of hypsodonty, not induced in such a case by a biotop deterioration (as it will happen at the end of the Eocene). This ínadaptation might account for the short duration of the genus Leptolophus, whose the 3 species, L. stehlini, L. nouletí and L. magnus n. sp. are indeed confined in the level MP 16. Its geographical spreading (as far as known, South of western Europe) and the morphological pattern of its dentition suggest that this genus would have been related to early upper Eocene endemic spanish forms.





  

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