jeanflop/post-ocr-correction huggingface dataset:
mêmes que pour la figure 1. According to Wang (1992), the faunal changes in Asia are not as sudden as in Europe and North America at the end of the Upper Eocene. Wang also noticed that rodents with more hypsodont teeth (Ctenodactylidae, Tsaganomyidae and Tachyoryctoididae) appear at the Lower-Middle Oligocene boundary. The appearance of rodents whose molars possess a more hypsodont crown generally characterizes an adaptive change in response to a vegetation typical of a more arid and open environment. This kind of environment occurred in Europe and North America at the Eocene-Oligocene boundary. Among other events stressed by Wang
at the Eocene-Oligocene boundary. Among other events stressed by Wang at the Lower-Middle Oligocene boundary, she noticed the extinction of Anagalida, Mesonychidae (Condylarthra), Brontotheriidae, Deperetellidae and Lophialetidae (Perissodactyla) and Yuomyidae (Rodentia). However, TABLE Diversity of mammal orders for different periods of the Paleogene in Asia. N = number of species; % = corresponding percentage; Up. Eoc. = Upper Eocene; L. Olig. = Lower Oligocene; M. Olig. = Middle Oligocene. Data from Russell and Zhai (1987). Only taxa whose determination was unambiguous were retained in that table. According to the new interpretation, columns A and B represent Upper Eocene faunas and
interpretation, columns A and B represent Upper Eocene faunas and column C represents Lower Oligocene faunas. Diversité des ordres de mammifères pour différentes périodes du Paléogène en Asie. N=nombre d'espèces; % = pourcentage correspondant; Up. Éoc. = Éocène supérieur; L. Olig. = Oligocène inférieur; M. Olig. = Oligocène moyen. Données tirées de Russell et Zhai (1987). Seuls les taxons dont la détermination était sans ambiguïté ont été retenus dans ce tableau. D'après la nouvelle interprétation, les colonnes A et B représentent l'Éocène supérieur et la colonne C représente l'Oligocène inférieur. ABC Up. Eoc. L. Olig. M. Olig. Orders N N
ABC Up. Eoc. L. Olig. M. Olig. Orders N N N Marsupialia 0 1 0,8 0 Chiroptera 0 1 0,8 0 Insectivora 2 1,8 3 2,6 15 10,4 Primates. 3 2,7 1 ? 0,8? 0 Pantodonta 1 0,9 0 0 Tillodontia 1 0,9 0 0 Lagomorpha 3 2,7 4 3,6 15 10,4 Rodentia. 5 4,6 10 8,9 47 32,6 Anagalida. 0 1 0,8 0 Mixodontia. 1 0,9 0 0 Carnivora. 3 2,7 2 1,8 12 8,3 Creodonta. 5 4,6 8 7,1 5 3,5 Condylarthra. 4 3,6 2 1,8 0 Perissodactyla 57 52,3 54 48,2 22 15,3 Artiodactyla 24 22 25
57 52,3 54 48,2 22 15,3 Artiodactyla 24 22 25 22,3 28 19,4 in other areas (North America and Europe), these extinctions occurred at the Eocene-Oligocene boundary. One of the last arguments suggested by Wang is the endemic character of the Oligocene Asian faunas. This endemism would therefore be explained by the fact that these faunas are older than actually considered. Indeed, it is very unlikely that faunal and climatic events that occurred in Europe and North America at the Eocene-Oligocene boundary also occurred in Asia, about 10 Ma later. The more satisfying solution is to consider that most of
The more satisfying solution is to consider that most of the alleged Oligocene Asian faunas must be older than actually thought. Thus, Chinese Lower Oligocene localities would fall into the Upper Eocene, and Middle Oligocene faunas would have to be shifted back into the Lower Oligocene. These conclusions are confirmed by the study of cenograms. The Upper Eocene and Lower Oligocene mammalian communities from Asia are generally not well diversified. The Upper Eocene faunas of Heti (Eastern China), Naduo (Southern China) and Krabi (Thailand), and the Lower Oligocene fauna of Ergilin-Dzo (Mongolia) have been chosen because they are the most
Ergilin-Dzo (Mongolia) have been chosen because they are the most representative by the diversity and the number of taxa they display. Similarly, the fauna of Hsanda-Gol (Mongolia) is the most diversified and complete Middle Oligocene community of Asia so far known, and it has been selected for these reasons. The cenogram method developed by Legendre (1989) enables a relationship to be indicated between the ponderal distribution of mammal species in a community and their environment. The structure of the cenogram is related to the general environment (structure of vegetation cover and climatic conditions) of a faunal community. As climatic conditions
and climatic conditions) of a faunal community. As climatic conditions markedly changed at the Eocene-Oligocene boundary, they must have been recorded in the structure of the mammalian communities, and thus the structure of the different cenograms should reflect the faunal and climatic conditions that existed before and after 34 Ma. Figure 2 shows that the cenograms constructed for the Asian Upper Eocene and Lower Oligocene faunas are very similar. Indeed, the large-sized species (in the left part of the diagram) are abundant and the corresponding slope is smooth. In addition, the medium-sized species are normally present. This structure indicates a
the medium-sized species are normally present. This structure indicates a humid and forested environment for these faunas. On the other hand, large-sized species are rare but medium- and small-sized species are abundant in the cenogram constructed for the Middle Oligocene fauna of Hsanda-Gol (fig. 2). The slope corresponding to large-sized species is steep and very different from that of smaller species. This structure is characteristic of an arid and more open environment, which corresponds to the environment that existed in Europe and North America at the beginning of the Lower Oligocene. Fig. 2. Cenograms of the Asian faunas classically considered
Oligocene. Fig. 2. Cenograms of the Asian faunas classically considered as Upper Eocene and lower Oligocene in age. Heti (Eastern China), Naduo (Southern China) and Krabi (Thailand) faunas: Upper Eocene; Ergilin Dzo fauna (Mongolia): Lower Oligocene. The Middle Oligocene fauna of Hsanda-Gol (Mongolia) is represented in superposition. In the present work, Heti, Naduo, Krabi and Ergilin Dzo are considered as Upper Eocene in age, and Hsanda-Gol is Lower Oligocene. Note the different orientation of the slope corresponding to the large (left part of the diagram) and small species (right part of the diagram). By comparison with European faunas, see figure
of the diagram). By comparison with European faunas, see figure 41, p. 46 in Legendre (1989). Fig. 2. — Cénogrammes des faunes classiquement considérées comme d'âge Éocène supérieur et Oligocène inférieur d'Asie. Faunes de Heti (Chine orientale), de Naduo (Chine méridionale) et de Krabi (Thaïlande) : Éocène supérieur; faune de Ergilin Dzo (Mongolie) : Oligocène inférieur. La faune Oligocène moyen de Hsanda-Gol (Mongolie) est présentée en superposition. Dans le présent travail, Heti, Naduo, Krabi et Ergilin Dzo sont considérées comme étant d'âge Éocène supérieur, et Hsanda-Gol est Oligocène inférieur. Noter la différence de pente correspondant aux grandes (partie gauche du
la différence de pente correspondant aux grandes (partie gauche du diagramme) et aux petites espèces (partie droite du diagramme). Par comparaison avec les faunes européennes, voir la figure 41, p. 46 dans Legendre (1989). The association of results displayed by the faunal structures and the cenograms indicates that a marked climatic and faunal change occurred at the Lower Oligocene-Middle Oligocene boundary in Asia according to the classical conception of Asian chronological scale. Such changes are also recorded in European communities at the Eocene-Oligocene boundary (Legendre and Hartenberger, 1992). In addition, the Eocene-Oligocene boundary turnover is considered to have occurred at
the Eocene-Oligocene boundary turnover is considered to have occurred at about the same time and at a global scale in Northern Hemisphere (Berggren and Prothero, 1992). As no similar large-scale events are known at the Lower Oligocene-Middle Oligocene boundary, it is therefore highly probable that the faunal and climatic changes recorded in Asia correspond to those that occurred in Europe and North America by about 34 Ma. These results would implicate that Asian Lower Oligocene must be shifted in the Upper Eocene, and that the Asian Middle Oligocene certainly corresponds to Lower Oligocene. These conclusions should be tested with more
to Lower Oligocene. These conclusions should be tested with more geochronological data such as paleomagnetism. If the biochronological changes proposed here are correct, several patterns concerning the evolutionary history of mammals (first appearance, migrations, last appearance among others) would have to be revised. Study of the Upper Eocene Krabi fauna from Thailand (Ducrocq et al., 1992) is a good example of what could be done in that field. Indeed, its mammalian community led to reconsideration of several steps of the evolutionary history of Asian mammals. In addition, the peculiar aspect of its components makes this fauna an important landmark for
of its components makes this fauna an important landmark for the Paleogene vertebrate record in Asia. The mammals from Krabi therefore permitted reappraisal of the Asian chronological scale. I wish to thank S. Legendre who suggested that I begin the present study, and for the discussions we had about the Eocene-Oligocene boundary in Asia. I also thank J.-L. Hartenberger and J.-J. Jaeger for their helpful comments during the writing of this paper. Note remise le 7 novembre 1992, acceptée après révision le 22 décembre 1992. REFERENCES W. A. BERGGREN and D. R. PROTHERO, Eocene-Oligocene climatic and biotic evolution: an overview,
D. R. PROTHERO, Eocene-Oligocene climatic and biotic evolution: an overview, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 1-28. C. CAVELIER, La limite Éocène-Oligocène en Europe occidentale, Thèse Doct. d'État, Univ. Pierre-et-Marie-Curie, 1979, 353 p. S. DUCROCQ, E. BUFFETAUT, H. BUFFETAUT-TONG, R. HELMCKE-INGAVAT, J.-J. JAEGER, Y. JONGKANJANASOONTORN and V. SUTEETHORN, A lower Tertiary vertebrate fauna from Krabi (South Thailand), N. Jb. Geol. Paläont. Abh., 184, 1, 1992, pp. 101-122. E. EVANOFF, D. R. PROTHERO and R. H. LANDER, Eocene-Oligocene climatic change in North America: the White River Formation near Douglas, East-Central Wyoming, Eocene-Oligocene climatic and biotic evolution,
Formation near Douglas, East-Central Wyoming, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 116-130. J.-L. HARTENBERGER, Crises biologiques en milieu continental au cours du Paléogene : exemple des mammifères d'Europe, Bull. Centres Rech. Explor.-Prod. Elf Aquitaine, 10, 2, 1986, pp. 489-500. G. KELLER, N. MACLEOD and E. BARRERA, Eocene-Oligocene faunal turnover in planktic Foraminifera, and Antarctic glaciation, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 218-244. S. LEGENDRE, Les communautés de mammifères du Paléogène (Éocène supérieur et Oligocène) d'Europe occidentale : structures, milieux et évolution, Münch. Geowiss. Abh., Reihe A, 16, 1989, pp. 1-100.
évolution, Münch. Geowiss. Abh., Reihe A, 16, 1989, pp. 1-100. S. LEGENDRE and J.-L. HARTENBERGER, Evolution of mammalian faunas in Europe during the Eocene and Oligocene, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 516-528. E. B. LEOPOLD, G. LIU and S. CLAY-POOLE, Low-biomass vegetation across the Eocene/Oligocene boundary, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 399-420. S. G. LUCAS, Redefinition of the Duchesnean Land Mammal "Age", Late Eocene of Western North America, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 88-105. K. G. MILLER, Middle Eocene to Oligocene stable
pp. 88-105. K. G. MILLER, Middle Eocene to Oligocene stable isotopes, climate and deep-water history: the Terminal Eocene Event? Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 160-177. J.-A. REMY, J.-Y. CROCHET, B. SIGÉ, J. SUDRÉ, L. de BONIS, M. VIANEY-LIAUD, M. GODINOT, J.-L. HARTENBERGER, B. LANGE-BADRÉ and B. COMTE, Biochronologie des phosphorites du Quercy : mise à jour des listes fauniques et nouveaux gisements de mammifères fossiles, Münchner Geowiss. Abh., A, 10. 1987, pp. 169-188. D. E. RUSSELL and R.-J. ZHAI, The Paleogene of Asia: mammals and stratigraphy, Mém. Mus. Nat. Hist. Nat., 52, 1987, 488
and stratigraphy, Mém. Mus. Nat. Hist. Nat., 52, 1987, 488 p. H. G. STEHLIN, Remarques sur les faunules de mammifères de l’Éocène et de l’Oligocène du Bassin de Paris, Bull. Soc. géol. Fr., 4, 9, 1910, pp. 488-520. R. K. STUCKY, Mammalian faunas in North America of Bridgerian to Early Arikareean Ages (Eocene and Oligocene), Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 463-493. B. WANG, The Chinese Oligocene: a preliminary review of mammalian localities and local faunas, Eocene-Oligocene climatic and biotic evolution, Princeton University Press, Princeton, 1992, pp. 529-547. Laboratoire de Paléontologie, Case Courrier n° 064,
1992, pp. 529-547. Laboratoire de Paléontologie, Case Courrier n° 064, URA n° 327, Université Montpellier-II, place Eugène-Bataillon, 34095 Montpellier Cedex 5, France. Micropaléontologie Micropaleontology La grande dispersion des espèces d'ostracodes (Crustacea) d’eau douce à la fin de l’ère primaire Francis LETHIERS et Renée DAMOTTE Résumé — Certaines espèces d'ostracodes lacustres de la fin du Paléozoïque sont découvertes sur plus de 4000 km de distance. Les données biologiques actuelles et des observations paléontologiques nouvelles, telles que la découverte d’espèces nord-américaines en France et au Maroc, suggèrent que les premiers tétrapodes et les tempêtes humides sont intervenus dans la dissémination de ces
les tempêtes humides sont intervenus dans la dissémination de ces espèces. Le deuxième facteur cadre bien avec les connaissances paléoclimatologiques de cette période. Wide dispersion of freshwater ostracod species during the late Paleozoic Abstract — Some late Paleozoic species of freshwater ostracods have been discovered in places more than 4,000 km apart. Modern biological data and new paleontological observations, such as North American species discovered in France and Morocco, suggest that the first tetrapods and humid storms affected the spread of these species. The climatic factor agrees well with the climatological data for the Late Paleozoic. Abridged English Version Stephanian-Autunian
climatological data for the Late Paleozoic. Abridged English Version Stephanian-Autunian (Late Carboniferous-Early Permian) times were characterized by continental events. The Variscan Mountains covered southern Europe and northern Africa. The collision between Africa and North America caused the last orogenic phase of the Appalachian-Mauritanian chain (map). Molassic sediments, principally clastic but including seams of coal and rare beds of carbonate, were deposited on the new continental areas. Lakes and swamps formed in small intramountain fault basins, especially in France and Morocco. Such lacustrine and paludal environments often shelter abundant ostracodes, whose microscopic fossilized valves are found on surfaces of shale or
microscopic fossilized valves are found on surfaces of shale or in calcareous beds. We have recently found species of ostracods in Permian continental beds in the Noyant-Souvigny Basin (North Massif Central, France) and in the Mechraâ Ben Abbou Basin (Meseta, Morocco) that were previously known from the northeastern United States. These species were first described from Upper Pennsylvanian (Virgilian) and Lower Permian (Wolfcampian) sediments in Illinois, Pennsylvania, and Virginia ([1], [2], [3]). The sediments were deposited in large swamps resulting from cyclic regressions of the North American epicontinental sea. The wide geographic distribution of continental species of ostracods poses a
wide geographic distribution of continental species of ostracods poses a question of how they are disseminated. Since their viable environments were discontinuous, how could the species spread abroad over a distance of more than 4,000 km, according to the most precise paleographic maps [4]? Moreover, the French and Moroccan basins were probably isolated by high reliefs of the Variscan ranges, and the North American swamps were enclosed by the Appalachian fold belt. The American-type ostracods found in Autunian beds in the Noyant-Souvigny Basin belong to two superfamilies, existing since the Carboniferous: 1) the Cypridoidea with near-specific or conspecific specimens of
Carboniferous: 1) the Cypridoidea with near-specific or conspecific specimens of "Cypridopsis" ovata (Holland 1934) (fig. 13), Candona magnitata (Holland 1934) (fig. 11), and "Candona" planidorsata Cooper 1946 (fig. 12); and 2) the Darwinuloidea with Darwinula cf. hollandi Scott 1944 (figs. 14-15) and Whipplella carbonaria Scott 1944 (figs. 1-8). Today members of these superfamilies still live in the same freshwater environments. The Cypridoidea are well adapted to propagation of species, because Note présentée par Jean DERCOURT. 0764-4450/93/03160427 $ 2.00 e Académie des Sciences their eggs can withstand desiccation, cold, and drops in atmospheric pressure. Their eggs can be carried by winds,
in atmospheric pressure. Their eggs can be carried by winds, even at high altitudes, to hatch in distant lakes [6]. Such an adaptive type was probably present in the Cypridoidea since the late Carboniferous. In modern times, migratory birds carrying desiccation-resistant eggs in mud attached to their feet are known agents in the spreading of ostracods [7]. In Stephanian-Autunian times, amphibians and early reptiles may have served similarly as agents of dissemination. The tetrapods were then already very diversified and still living in aquatic environments [8]. The large dispersion of modern species of Darwinuloidea is more difficult to explain. In
modern species of Darwinuloidea is more difficult to explain. In this superfamily, females often brood eggs and the first two larval stages in the posterodorsal part of the inner cavity. Thus, their eggs are not resistant to desiccation [10]. Such species can survive only in a permanent freshwater environment. Transport of their eggs by dry winds seems impossible. Transport of ostracods eggs by hurricanes and windy rainstorms has been suggested [11]. 9-10), which we have discovered in France and Morocco, already in the Autunian brooded eggs and first larvae. This brooding is demonstrated in thin section showing immature valves inside
brooding is demonstrated in thin section showing immature valves inside a carapace (fig. 8). The fossilized carapaces are closed, filled with sediment-free, sparry calcite, showing that the immature valves are not an external contamination. Death of these females and their larvae was probably caused by the draining of part of the lake. How can we explain the vast distribution of this species and other species of Darwinuloidea that could not survive desiccation? Perhaps the early tetrapods carried ostracods on wet mud clinging to their feet. Another possibility is that the ostracods or their eggs were carried in the intestines of
ostracods or their eggs were carried in the intestines of the tetrapods that fed upon aquatic plants. This method of transport has been demonstrated with modern fishes [12]. Such methods of transport from pond to pond would lead to an efficient dispersal in several thousand years, hardly an instant in geological time. Transport by humid winds is the remaining hypothesis. Our reconstruction of Stephanian-Autunian paleogeography ([4], [14]) shows that the regions studied are situated in the middle part of Pangea [15] and lay between latitudes 10° north and 10° south (map). This zone then had a warm tropical climate. Lithic
(map). This zone then had a warm tropical climate. Lithic indicators of paleoclimate [16], flora [17] and numerical simulation of the climate of Pangea ([18], [19]) support this inference. In such a climate, humid winds (monsoons), windy rainstorms, and hurricanes can carry water and wet particles. Humid winds were probably especially strong in the regions studied because of air currents strengthened in response to the relief of the Variscan and Appalachian Ranges. Beginning in the Late Carboniferous, some species of freshwater ostracods became well adapted to methods of dissemination that are known today. The early tetrapods may have aided dissemination
are known today. The early tetrapods may have aided dissemination in a time of coevolution. Paleoclimatic and orographic data for Stephanian-Autunian times suggest, however, that humid winds were the most important agents in spreading of freshwater ostracods. I. GÉNÉRALITÉS. — Les temps stéphano-autuniens (fin Carbonifère et début Permien) sont caractérisés par le phénomène de la continentalisation. La chaîne varisque couvre le Sud de l'Europe et l'Afrique du Nord. La collision entre l'Afrique et l'Amérique du Nord donne la phase finale de l'orogenèse des Appalaches-Mauritanides (carte). Les nouvelles surfaces continentales créées entraînent une sédimentation, de type molassique, essentiellement clastique mais pouvant
entraînent une sédimentation, de type molassique, essentiellement clastique mais pouvant présenter des veines de charbons et plus rarement des lits carbonatés. En particulier, en France et au Maroc, des milieux lacustres et palustres s'intallent dans des petits bassins d'effondrement intramontagneux. Ce type d'environnement abrite souvent une faune abondante d'ostracodes dont on retrouve les valves microscopiques fossilisées à la surface des shales ou dans les lits calcaires. II. LE PROBLÈME DE LA DISPERSION DES ESPÈCES LACUSTRES. — Nos investigations récentes dans le Permien continental du Bassin de Noyant-Souvigny (Nord du Massif Central, France) et dans le Bassin de Mechraâ Ben Abbou
Central, France) et dans le Bassin de Mechraâ Ben Abbou (Meseta, Maroc) ont mis en évidence des espèces d'ostracodes lacustres connues dans le NE des États-Unis d'Amérique. Elles furent décrites dans le Pennsylvanien supérieur (Virgilien) et le Permien basal (Wolfcampien) de l'Illinois, Pennsylvanie et Virginie Orientale ([1], [2], [3]). Les espèces et les genres sont bien identifiables à l'aide des empreintes des muscles adducteurs (fig.7). Là il s'agit de dépôts dans de vastes marécages issus de phases régressives cyclothémiques de la mer épicontinentale nord-américaine. La grande répartition géographique de ces espèces continentales pose le problème de leur propagation. En effet
espèces continentales pose le problème de leur propagation. En effet le milieu de vie étant discontinu, comment une espèce pouvait-elle se propager sur une distance supérieure à 4 000 km d'après les reconstitutions paléogéographiques les plus précises [4]. De plus, les bassins continentaux de France et du Maroc étaient probablement isolés par des reliefs élevés de la chaîne varisque et la zone plissée appalachienne enclavait les marécages nord-américains. Pour répondre à cette question il est nécessaire de se référer à la biologie des ostracodes d'eau douce. III. LES DONNÉES BIOLOGIQUES ACTUELLES. — Les ostracodes de type américain qui sont retrouvés
ACTUELLES. — Les ostracodes de type américain qui sont retrouvés dans l'Autunien de Noyant-Souvigny (France) appartiennent à deux superfamilles connues depuis le Carbonifère: 1) les Cypridoidea avec des espèces proches sinon conspécifiques de « Cypridopsis » ovata (Holland, 1934) (fig. 13), « Candona» magnitata (Holland, 1934) (fig. 11) et « Candona » planidorsata Cooper, 1946 (fig. 12); 2) Les Darwinuloidea avec Darwinula cf. hollandi Scott, 1944 (fig. 14-15) et Whipplella carbonaria Scott, 1944 (fig. 1-8). Ces deux superfamilles vivent toujours actuellement dans les mêmes milieux continentaux et leur mode de propagation peut nous aider à comprendre celui des formes du