Regional Subdivisions and Correlations

M. A. ALVAREZ SIERRA, R. DAAMS, J. I. LACOMBA, N. LÓPEZ MARTÍNEZ & M. A. SACRISTÁN MARTIN:
Succession of micromammal faunas in the Oligocene of Spain

Seven units are recognized in the Spanish continental Oligocene on the basis of the micromammalian content, named P, Q, R, T, U, V, and W respectively. The limits of the Oligocene are discussed and the Oligocene/Miocene boundary interval in continental sediments is defined, containing units X and Y 1.

L. de BONIS & Y. GUINOT:
Le gisement de Vertébrés de Thézels (Lot) et la limite Oligo-Miocène dans les formations continentales du bassin d'Aquitaine

Almost unknown until now, the fossiliferous locality of Thezels (Lot, France) hay yielded a rich mammalian fauna with both large and micro mammals. It is located south of Cahors on the north-eastern margin of the Aquitaine basin. The fossils are in a limestone which is a term of a series composed by the Cieurac limestone and the aquitanien limestones.

The mammal fauna is younger than the classical fauna of La Milloque and older than the Paulhiac fauna (early Agenian = early Aquitanian). It is equivalent of the type-level of Coderet. Problems of correlations with marine sediments and stages are also discussed.

M. BRUNET, L. de BONIS & P. MICHEL:
Les grands Rhinocerotidae de l'Oligocène supérieur et du Miocène inférieur d'Europe occidentale: intérêt biostratigraphique

The super-family Rhinocerotoidea was known in western Europe from the early Oligocene with three families: Hyracodontidae, Amynodontidae and Rhinocerotidae. Among the latter we study the most important anatomical features and the time distribution of two large genera, Ronzotherium and Diaceratherium. The former was known during almost the whole Oligocene and the latter during the early Miocene. Some authors claimed the two genera have coexisted during the late Oligocene but we show that they did not. Ronzotherium arrived in Ronzon (early Oligocene) and occured for the last time in Rickenbach and Comberatiere (late Oligocene). Diaceratherium replaced it from La Milloque (latest Oligocene) with the species D. lamilloquense which is succeeded in the Miocene by D. lemanense and D. aginense. The anatomical features which allow to recognize the two genera are described. This faunal turn-over is a pretty good stratigraphic level in the late Oligocene of western Europe.

B. ENGESSER & N. A. MAYO:
A Biozonation of the Lower Freshwater Molasse (Oligocene and Agenian) of Switzerland and Savoy on the basis of fossil Mammals

In the course of a project funded by the Swiss National Sciences Foundation, a biozonation of the Molasse of Switzerland and Savoy has been worked out. This study, begun in 1978, is based on old collections and on new material, collected from previously known and new localities, whenever possible in measured sections. The new zonation contains 18 mammal assemblages beginning at the top of the Lower Oligocene (assemblage zone of Balm) to the uppermost Agenian (or Aquitanien, assemblage zone of Mt Vully = MN 2b). In contrast to previous zonations, entire mammal faunas have been used, which were obtained only from stratified localities. The zones were worked out on the basis of the evolutionary levels of well known evolutionary lines, of appearance and disappearance of certain taxa, and of typical associations. Each zone has been defined by a reference fauna of which a faunal list is given. In addition, as many Molasse faunas as possible of about the same age (more than 100 all together) were integrated in each zone. Correlations with well known mammal faunas outside the Molasse basin have been attempted. The mammal zonation of the Upper Marine Molasse and the Upper Freshwater Molasse will be published elsewhere.

V. FAHLBUSCH & K. HEISSIG:
Rodents at the Oligocene/Miocene boundary near Rottenbuch (Southern Bavaria)

In the center of the Rottenbuch syncline (Subalpine Molasse, Southern Bavaria) a sequence of limno-fluviatile and partly brackish-marine sediments documenting the Oligocene-Miocene transition is exposed. At localities along the Ammer River near Rottenbuch micromammals (mostly rodents) have been found at 48 stratigraphic levels. These local faunas belong to mammal units MP 30 (Coderet) and MN 1 (Paulhiac}. Among about 25 species of rodents (represented by about 2500 isolated teeth) cricetids are dominant (especially Eucricetodon aff. haslachensis and Eucric. cf. collatus). Rhodanomys transiens and Eomys sp. are common, but theridomyids are completely missing. In higher parts of the section, which according to land- and freshwater-snails belong to the Aquitanian, eomyids (forms transitional between Rhodanomys transiens and Rh. schlosseri) are more common than various species of the Pseudotheridomys-group. Ancient elements (Gliravus and Adelomyarion) are missing here. Glirids are moderately represented in all localities but of less biostratigraphic importance. Different sciurid species are rare. – The MP 30/MN 1-boundary (Arvernian/Agenian) is discussed.

J. L. FRANZEN & H. HAUBOLD:
The biostratigraphic and palaeoecologic significance ofthe Middle Eocene locality Geiseltal near Halle (German Democratic Republic)

It is suggested to take the geologic section of the Geiseltal near Halle (GDR) as a base for a new biostratigraphic subdivision of the European Middle Eocene founded on terrestric mammals. 4 mammal levels are distinguished: The lower coal seam, the lower part of the middle coal seam, and the upper part of the middle coal seam plus the upper intermediate layer represent the whole Middle Eocene whereas the mammals from the upper coal seam already substantiate the lowermost Late Eocene. This concept of mammalian biostratigraphy is directly controlled by superposition as well as by several autochthonous chronoclines, and it is correlated at the same locality with the palynological zonation of the European Paleogene. The fauna from Messel is surprisingly different from that of the contemporaneous lower coal seam of the Geiseltal, particularly with respect to the lack of micromammals in the lower coal seam and of large mammals, e.g. lophiodonts, at Messel. This difference is primarily explained by principal difficulties concerning the recovery of small mammals from lignite on one hand and by transport selection in the case of Messel on the other. The striking faunal turnover at the end of the Middle Eocene (»petite coupure«) coincides with a somewhat cooler phase of climatic development.

K. HEISSIG:
Changes in the rodent and ungulate fauna in the Oligocene fissure fillings of Germany

The relative stratigraphic succession of the fissure fillings in Southern Germany is established more precisely. For this purpose the size evolution of the genus Suevosciurus is used. This genus is grouped in three species instead of two, each showing a different speed in size increase. The smallest hitherto unnamed species is proposed as Suevosciurus dehmi n.sp. The correlation with the French standard localities is made by large mammals but remains still questionable in some details.

J. J. HOOKER:
Mammalian faunal events in the English Hampshire Basin (late Eocene – early Oligocene) and their application to European biostratigraphy

The southern English Hampshire Basin provides a nearly uninterrupted late Eocene to early Oligocene sequence of essentially non-marine strata, containing numerous mammal-bearing levels. Information from old and new collections forms the basis for a relatively accurate documentation of the stratigraphic ranges of many of the taxa. This is applied in two ways: 1) to test the order of occurrence of faunas and of successive stages in evolutionary lineages as postulated by authors for continental Europe, where superpositional evidence is often missing; and 2) to establish a series of biozones in the late Eocene, based on geographically widespread taxa, which can act as a broad biostratigraphic framework of conventional type applicable throughout much of Europe.

M. HUGUENEY, R. ADROVER, E. MOISSENET & N. SCHMIDT-KITTLER:
Les Mammifères de Vivel del Río (prov. de Teruel, Espagne; Oligocène supérieur): un riche gisement stratifié en comparaison avec des faunes karstiques

Vivel de Río is a rich mammal locality interstratified in calcareous marls and limestones of the Vivel-Montalbán syncline.

Detailed study of the families relevant for biostratigraphy (Theridomorphs, Cricetids, Eomyids) indicates an Upper Oligocene age, a little more ancient than the classical karstic localities, Gaimersheim (N fissure, Germany) and Pech-du-Fraysse (Quercy, France). In Vivel, absolute size and dental morphology of the most abundant species exhibit considerable individual variation, which is almost as large as in fissure fillings. Comparison of the species components of the various faunas shows the great homogeneity of the European mammalian communities at this exact level of the Upper Oligocene.

Due to its position in a stratigraphical sequence and to the variety and richness of its fauna, Vivel del Río will play an outstanding role in correlations.

Y. JEHENNE:
Intérêt biostratigraphique des Ruminants primitifs du Paléogène et du Néogène inférieur d'Europe occidentale

Two new species of primitive Ruminantia (Pecora) from the Oligocene of western Europe are described as Gelocus quercyi nov. sp. and Dremotheriumguthi nov. sp.

The stratigraphical distribution of the primitive Pecora from the Paleogene and the early Neogene shows three faunal turn-over during this period. Thus it appears that the primitive Ruminantia can be considered as good biostratigraphic fossils.

S. LEGENDRE:
Les immigrations de la »Grande Coupure« sont-elles contemporaines en Europe occidentale?

The evidence from analysis of late Eocene and Oligocene mammalian faunas for a climatic crisis, which is contemporaneous with the migrations of the »Grande Coupure« in France and occurs posteriorly to them in southern Germany, produces the problem of correlations between biochronological scales of the two provinces and that of the synchronism of the Oligocene immigrations in western Europe.

B. MARANDAT:
La biostratigraphie mammalienne de l'Eocène continental du versant sud de la Montagne Noire. Reconsidération d'après les nouvelles données

The problems of dating and correlating the Eocene continental series of the southern slope of the Montagne Noire are treated on the basis of new mammalian material. ft can be demonstrated by the new informations that the limestone of Agel (Minervois) and the red clays of Issel belong to the Upper Cuisian. The biostratigraphic data of the classical »Grès d'Issel« mammalian fauna indicate a time span from the Upper Lutetian up to the Upper Bartonian. It can be shown that in the sedimentary sequence of the Minervois part of the Lutetian is lacking. A comparable gap is supposed for the sequence of Issel though this cannot definitely be demonstrated. New regional correlations are proposed.

N. A. MAYO:
The Development of the Theridomyidae in the OligoceneMolasse of Switzerland and Savoy

This paper reports the regularity of the evolution and distribution of the Theridomyidae during the Oligocene in the Swiss-Savoy faunal province. The subfamily Theridomyinae has been found only in the oldest levels. Isoptychus is present with several new species up to the Oensingen-Ravellen level. Until now Theridomys s.str. is represented by only one tooth of a species less evolved than Th. lembronicus. Blainvillimys is well represented only in the Mümliswil-Hardberg level. The subfamily Archaeomyinae occurs early in the Balm and La Combe levels and from then on grows to predominance until its extinction in the Küttingen level. Rhombarchaeomys and the primitive archaeomyids are dominant in the Lower »Chattien«. Protechimys is poorly represented. Archaeomys s.str. and Issiodoromys s.str. were immigrants that mark the beginning of the Upper »Chattien« in the Swiss-Savoy faunal province.

Finally, the complex development of the Issiodoromyinae subfamily in this province is explained. Nesokerodon is represented by several successional species. Oensingenomys occurs in Oensingen-Ravellen and Boningen levels. Issiodoromys has two principal lines of successional species, although these are not the only taxa of Issiodoromyinae represented in the uppermost layers of the Oligocene molasse. All these successional species of Therdomyidae (not all published as yet) are distinguished by the maximum number available of diagnostic characters and biometric methods.

J. A. REMY, J.-Y. CROCHET, B. SIGÉ, J. SUDRE, L. de BONIS, M. VIANEY-LIAUD, M. GODINOT, J.-L. HARTENBERGER, B. LANGE-BADRÉ, B. COMTE:
Biochronologie des phosphorites du Quercy: Mise àjourdes listes fauniques et nouveaux gisements de mammifères fossiles

Since 1965 the continuous exploitation of the fissure fillings of the Quercy has yielded more than 70 fossil mammal faunas. The observed species associations and the represented evolutionary stages lead to the attribution of these faunas to 5 reference levels of the late Eocene and 8 reference levels of the Oligocene, extending from the level of Robiac (Marinesian) to the level of Pech du Fraysse (late Stampian).

M. RINGEADE:
Séquences mammaliennes en Aquitaine: corrélations avec les zones à Mammifères classiques, les zones à Charophytes et à Ostracodes

The exploitation of new vertebrate sites at Blaye (level of Robiac), at Baby (Fons 4), at Civrac (La Débruge), at Sainte-Croix de Beaumont, Saint-Martin de Villeréal and Maransin (Escamps), at Baby 2 and at Saint-Capraise d'Eymet (St. Capraise), and the evolutive study of Perissodactyla and of Artiodactyla of these vertebrate horizons of the North Aquitaine Paleogene, makes it possible to improve the biostratigraphy of the continental formations of this region.

The intercalation of certain continental levels with local marine facies enable correlations to be made between marine and continental scales through the studies of ostracoda by O. Ducasse. Previous studies of the charophyta of the region can be perfectly integrated in these biostratigraphic reconstitutions.

H. TOBIEN:
The Position of the »Grande Coupure« in the Paleogene of the Upper Rhine Graben and the Mainz Basin

The brackish-marine Paleogene section of the sedimentary sequence in the Rhine Graben tectonic system including the Mainz basin offers the possibility to recognize the relevant mammalian niveaus below and above the »Grande Coupure«. This faunal turnover is to locate above the Middle Pechelbronn Fm. with its NP 22 nannoplankton datum. The transition of the NP 21/NP 22-zones defines the boundary between Latdorfian (= Lower Oligocene) and Rupelian (= Middle Oligocene).

The present state of knowledge allows to place provisionally the »Grande Coupure« at the Latdorfian/Rupelian (= Lower/Middle Oligocene) transition (thus abandoning the former concept as a marker for the Eocene/Oligocene boundary).

E. ÜNAY & H. de BRUIJN:
Middle Oligocene to Early Miocene Rodent assemblages from Turkey, a preliminary report

The composition of four Turkish rodent faunas ranging in age from M. Oligocene to E. Miocene is analysed. It is shown that the Turkish associations differ from West European and East Asiatic ones of similar age in the dominance of Muroidea. The relative abundance and diversity of Muroidea is considered to be a characteristic of the Eastern Mediterranean fauna province irrespective of biotope. The rodent associations from the Eastern and Western Mediterranean show considerable similarity if the Muroidea and Theridomyidae are not taken into account.

Correlation of the Turkish faunas with the West European standard sequence is hampered by the absence of Theridomyidae in the Eastern Mediterranean.

M. VIANEY-LIAUD & N. SCHMIDT-KITTLER:
Biostratìgraphie de l'Oligocène d'Europe: importance des lignées-guides de rongeurs Theridomyidae, et particuliérement des Issiodoromys

Due to the morphometric analysis of evolutionary lineages of the Theridomyidae, particularly that of Issiodoromys, it is possible to confirm and refine the biochronologic scale of the European continental Oligocene. The information drawn from several evolutionary lineages leads to a more precise correlation between the localities of different sedimentary basins.

Faunas and Paleoecology

M. T. ANTUNES, C. ESTRAVIS & D. E. RUSSELL:
A New Condylarth (Mammalia) from the Early Eocene of Silveirinha, Portugal

1 new condylarth, Microhyus reisi n.sp., from the early Eocene site of Silveirinha, Portugal, is described. It is compared with Microhyus musculus and with species of Louisina; its affinities and evolutionary tendencies are discussed. The presence of Microhyus in the Silveirinha fauna implies for the latter a very early Eocene age. The relative primitivity of M. reisi with respect to M. musculus also suggests that the fauna is older than those known from the more northern part of Europe.

M. BRUNET & J. SUDRE:
Evolution et systematique du genre Lophiomeryx POMEL 1853 (Mammalia, Artiodactyla)

The discovery of fossil remains of Lophiomeryx in new stratigraphically well dated localities shows the exact extension in time of this genus in the Oligocene of Western Europe. The predominant part of the collected material belongs to the type species L. chalaniati. The genus evolves from the reference level of Villebramar up to the level of Pech-du Fraysse and comprises the two evolutionary stages L. mouchelini n. sp. and L. chalaniati POMEL 1853. L. mouchelini n. sp. has been defined on the dental material from Villebramar. Due to the dental and postcranial material collected from the locality of Garouillas (Quercy) the morphologic variability and the features of the appendicular skeleton of the species chalaniati can be described more precisely.

Following this study two other species, L. gaudryi FILHOL and L. minor LYDDEKER, which are only known by their type specimens, can for the moment, only hypothetically be asserted to this genus.

The characters of the genus Lophiomeryx, within which also several species of the Asian Oligocene are included, and the systematic relationship to other archaic ruminants are shortly discussed.

L. CASANOVAS-CLADELLAS & J. SANTAFE-LLOPIS:
Cantabrotherium truyolsi n.gen. n.sp. (Palaeotheriidae, Perissodactyla), un exemple d'endémisme dans le Paléogène Ibérique

In this article a part of the Perissodactyl material of the locality Llamaquique (Oviedo, Spain) is presented. Based on the special features of an upper jaw with milk teeth and permanent dentition a new form of paleothere, Cantabrotherium truyolsi n.gen. n.sp., is described. It shows most affinities to Palaeotherium but cannot be attributed to this genus because of the primitive features of its dentition, the enormous size and its very advanced hypsodonty. The relationships of the jaw to an other specimen found by CRUSAFONT et al. in a locality of Central Spain allows to date the levels of Llamaquique as Upper Eocene (Upper Ludian).

O. FEJFAR:
A Lower Oligocene mammalian fauna from Détañ and Dvérce NW Bohemia, Czechoslovakia

Until 1979 only some scattered informations indicated the occurence of Oligocene vertebrates in the Bohemian Massive. A new fossiliferous layer has been recently discovered in volcanic tuffs together with leaf floras. The sites Detan and Dvérce are on the border of an Oligo-Miocene large stratovolcano (Doupov hills). Here, on the base of the 50 and 25 m thick tuffs, highly fragmented and dispersed skeletal remains were collected. The assemblage comprises: Amphiperatherium, Quercysorex, Hyaenodon, Pseudocynopsis, Anthracotherium, Elomeryx, Entelodon, Lophiomeryx, Pseudogelocus, Bachitherium, Paroxacron, Propalaeochoerus, Ronzotherium, Palaeosciurus, Plesiospermophilus, Suevosciurus, Gliravus, Eomys, Eucricetodon, Pseudocricetodon, Paracricetodon. It indicates a Stampian post-grandecoupure age – biozones Soumailles – Ronzon. Datations based on biotite are 37.7±1.5 m.y.

O. FEJFAR:
Oligocene Rodents from Zallah Oasis, Libya

In 1961 ARAMBOURG and MAGNIER reported on Palaeomastodon and Phiomia in the vicinity of the Zallah Oasis in central Libya. Extensive seaving and washing of the fossiliferous deltaic channel sands and claystones presented 3 taxa of phiomyids (Rodentia, Mammalia) from two sites in the same stratigraphic level. This is a further proof of the equivalents of the Jebel Qatrani formation at Fayum, Egypt in Libya. In the same strata, a rich for a miniferal assemblage with Bolivina melettica and Nummulites fichteli date these deposits as Rupelian-early Chattian.

J. GAD:
Theridomys brachydens n.sp., a new Theridomys species from Möhren (South Germany)

A new Theridomys species from the fissure fillings Möhren 13 and Möhren 19 (Fränkische Alb, South Germany) is described. Additional material of Theridomys aquatilis from these fissure fillings indicates Soumaille level for Möhren 19 and Villebramar level for Möhren 13.

M. GODINOT, J.-Y. CROCHET, J.-L. HARTENBERGER, B. LANGE-BADRÉ, D. E. RUSSELL & B. SIGÉ:
Nouvelles don nées sur les mammifères de Palette (Eocène inférieur, Provence)

New taxa from Palette are described: the creodont Parvagula palulae n.gen. n.sp. LANGE-BADRÉ, the primate Donrussellia magna n.sp. GODINOT, the rodent Pseudoparamys cezannei n.sp. HARTENBERGER, the condylarth Midiagnus praecipuus n.gen. n.sp. RUSSELL and the perissodactyl Cymbalophus hookeri n.sp. GQDINOT. Other forms, such as the marsupial Peratherium constans, the mesonychid Oissacus cf. europaeus and the identified lipotyphlans and chiropterans contribute, with the remaining fauna, to suggest for Palette an age close to that of the Dormaal reference level, and probably even older. The authors emphasize the inconsistency of the Franimorpha concept within rodents, and the probability of an Eurafrican origin for the perissodactyls, adapids and hyaenodontids.

J. I. LACOMBA & J. MORALES:
Los mamíferos del Oligoceno superior de Carrascosa del Campo (Prov. Cuenca, España)

Fourteen mammal taxa are determined in the Arvernian (Upper Oligocene) of Carrascosa del Campo (prov. of Cuenca, Spain). The rodent association contains only five species, in which Issiodoromys minor (33 %) and Gliravus alvarezae n.sp. (56 %) predominate.

Of the more than 4200 remains of large mammals, the rhinoceros Eggysodon osborni is represented by more than 75 %. Metriotherium mirabile, the youngest dichobunid of the european faunas, is also well represented.

The fauna of Carrascosa is interpreted to have lived in an open little forested landscape, with a relatively dry and warm climate.

S. LEGENDRE:
Les communautés de mammifères d'Europe occidentale de l'Eocène supérieur et Oligocène: structures et milieux

Mammalian faunas from the late Eocene and Oligocene of southern France, southern Germany and southern England are analysed with the cenogram method. This analysis shows that a drastic change in the structure of faunas takes place at the Eocene-Oligocene Boundary in all the studied areas. This change seems to result from a climatic crisis, which modifies the environments in western Europe: from warm and humid they become colder and more arid. Some ecological differences can be noted between the several European paleoprovinces.