Des chambres de pupation de Dermestidae (Insecta : Coleoptera) sur un os de mammifère tertiaire (phosphorites du Quercy) : implications taphonomiques et paléoenvironnementales

The larvae of some species of Dermestidae (Coleoptera) are able to bore the bones of a carrion for pupation. Several pupal chambers have been observed on an unciform belonging to a fossil rhinocerotid (Mesaceratherium sp.) from the late Oligocene/earliest Miocene of the phosphorites of Quercy (SW France). Such an unusual observation demonstrates the occurrence of dermestids in the entomofauna of the phosphorites of Quercy, and suggests at least the existence of paleoclimatic episodes with dry seasons, during a period usually considered as a relatively humid one. This is the earliest occurrence of such ichnofossils on a fossil mammal bone.     

Biostratigraphie d’après les foraminifères et paléoenvironnements des séries post-Éocène du sondage ASHTART 28, golfe de Gabès (Tunisie)

The Cenozoic sequence of Ashtart 28 well drilled in the Gulf of Gabes (Tunisia) is the subject of a biostratigraphical study. The samples recovered in cuttings from 390 m and downwards allowed to recognize, above the Late Eocene sediments, a sedimentary series, lithologically diversified, nearly 1600 m thick. Marine Pliocene deposits, generally attesting a low bathymetry, lie unconformably above the Messinian (Oued Bel Khedim formation), which shows the usual features of the Mediterranean confinement. The underlying Messinian pre-evaporitic platform series (Melqart formation), that is over 250 m thick, is typical of a perireefal environment. The sediments assigned to the Tortonian (Somâa Sands formation) are continental and occur unconformably above the approximately 500-metres-thick Middle Miocene strata (Saouaf, Mahmoud, Aïn Grab and Salammbô pars formations). The marine Lower Miocene and Oligocene sediments (Salammbô pars and Ketatna formations), that are more than 300 m thick, lie in continuity under the Middle Miocene. The infralittoral Chattian sequence has especially supplied a diversified assemblage of larger foraminifera recovered in other west-mediterranean basins. Datings were obtained based on planktonic and larger benthic foraminifera (Miogypsinidae, Nummulitidae, Lepidocyclinidae) and by correlations obtained by means of well loggings and lithostratigraphy. Benthic foraminifera, mainly listed for the Miocene and Oligocene, are studied from a systematic, stratigraphic and paleogeographic point of view. The paleoenvironments of deposits are defined for each considered stratigraphic interval. Comparisons are sketched with other drillings of the Gulf of Gabes. Thanks to the numerous data obtained by this detailed study, the Ashtart drilling can serve as a reference for the Tertiary sequence of this part of the Mediterranean domain.     

海南岛第三纪沉积环境与古植物群落的多样性及其变迁

海南岛第三纪沉积类型及古植物群落复杂多样,早第三纪主要为河湖泊,湖泊相和湖沼相等沉积,晚期发生海侵,开始出现海陆交相沉积;古植物群落主要有：温带山地针叶林和落叶阔叶林,亚热带常绿和落叶阔叶林,晚晚开始出现红树林,总体属温暖湿珠亚热带气候,晚第三纪海侵加大,沉积为型为滨海相,滨海－浅海相,浅海相及深水广海相等海相沉积,在滨海地区红树林面积大大增加,盆地中心平原地上展为低地热带雨林,总体属炎热潮湿的热带气候,但在海南岛西部和西北部仍发育有山地雪松和云杉林,上新世时植被类型逐渐接近现今当地的面貌,深入研究本区第三纪古环境与古植物群落的变迁对海南岛现代生物多样性形成机制的研究具有重要意义。     

Major vegetation trends in the Tertiary of Patagonia (Argentina): A qualitative paleoclimatic approach based on palynological evidence

The patterns of Patagonian vegetation change suggest a strong relationship between the major thermal characters of the flora and the global paleoclimatic trends during Tertiary times. This conclusion was reached from the assessment of fossil pollen data from Patagonia throughout the Paleogene and Early Neogene periods and the subsequent comparison of palynological data to the global deep-sea oxygen isotope record. Four main time intervals were recognized based on the temporal distribution of selected angiosperm key taxa. (1) Paleocene to Early Eocene: presence of megatherm elements (e.g. Nypa, Pandanus), probably integrating mangrove communities in Patagonian lowlands. (2) Middle Eocene to Early Oligocene: rise to dominance of mesotherm and microtherm Nothofagus species. Megatherm taxa were well recorded at the beginning of this interval (e.g. Ilex) but were shown to disappear towards the end. (3) Late Oligocene to Middle Miocene: new increases of megatherm taxa such as palms, Cupania and Alchornea. First occurrences of mesotherm Asteraceae, represented by trailing Mutisieae, were reported. (4) Late Miocene: dispersal of meso-microtherm and arid adapted taxa (e.g. Ephedraceae and Asteraceae) across the non-Andean region of Patagonia. Microtherm Nothofagacean forests probably occurred on the higher rainfall regions of western Patagonia. The current vegetation was most likely reached during this last stage with the forest development under wetter conditions on the Andean sectors, and the steppe throughout the non-Andean region of Patagonia.     

湖北南襄盆地枣阳凹陷第三纪轮藻化石及其地层意义

本文研究了南襄盆地枣阳凹陷第三系玉皇顶组到凤凰镇组轮藻化石。共划分出４个组合,其时代分别属早始新世、中始新世、晚始新世和渐新世。     

Données nouvelles sur les mammifères et les nummulites de l'éocène supérieur subalpin (synclinaux du Charbon et d'entrevernes,Bauges, Savoie et Haute-Savoie)

Vertebrate remains and nummulites have been investigated from the Late Eocene—Early Oligocene transgressive sequence of the «Chaînes subalpines south of the lake Annecy. The sedimentary environments range from fluvio-lacustrine shales and conglomerates at the base to hemipelagic Globigerina shales at the top. The fluvio-lacustrine white marls contain mammals of the upper, probably terminal Ludian, with affinities to the assemblage of Saint-Capraise. The brackish Cerithium beds have furnished charophytes of the Bembridge zone. The nummulite limestones are not dated precisely, but isolated, probably redeposited nummulites from the base of the Globigerina shales are of terminal Eocene or basal Oligocene age. The Globigerina shales themselves belong to the Oligocene.     

New data on the Cainotheriidae (Mammalia, Artiodactyla) from the early Oligocene of south-western France

The Cainotheriidae are small artiodactyls that suddenly appeared in the late Eocene of western Europe. A revision of early Oligocene cainotheriid lineages is proposed on the basis of newly dated material from the Quercy Phosphorites (south-western France). A significant diversification of the group occurred at the end of the Eocene. Few species seem to have persisted through the Eocene/Oligocene boundary, but the Cainotheriidae subsequently diversified rapidly during the early Oligocene.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 145−166.     

DISCOVERY OF TWO MID-TERTIARY MAMMALIAN FAUNAS FROM HAIYUAN, NINGXIA, CHINA

Inl988-199otheRegionalGeologicalSurveyTeamoftheGeologicalBureauofNingxia(RGSN)foundsomefossilmammalsinthelowerpartoftheHo11g1iugouFormationandtheupperpartoftheOligocene.Inl992ajointteamoflnstituteofVertebratePaleontologyandPaleoanthropo1ogy,AcademiaSinica(IVPP),andtheRGSNwenttoHaiyuailCountyandcollectedmorefossilmamma1sfromtheYuanjia-wowoareausi11gascreen-washingmethodThemammalfaunafromthelowerpartoftheHongliugouFormationiscomposedofAprotodonsp.,Indricotheriidaeindet.,Rhinoceroti…     

British mammals in the Tertiary period

British Tertiary mammals are best represented in the Eocene and earliest Oligocene epochs. Additional occurrences are from the Miocene and Late Pliocene. The Eocene is marked by the occurrence of various extinct orders as well as the appearances of some of the earliest and must primitive artiodactyls and perissodactyls. The appearances in the Early Eocene and Early Oligocene represent major dispersal events, reflecting penecontemporaneous palaeogeographic changes. In the intervening timespan Britain was part of an European island, sharing its endemic terrestrial fauna. From the late Middle Eocene to earliest Oligocene, the British record is detailed enough to trace successive changes in the patterns of diversity and faunal turnover, which may relate to changing climate as well as to the dispersal events. It has been shown that changes in patterns of ecological diversity through the Eocene and earliest Oligocene match vegetational changes judged from plant fossils. They suggest a gradual transition from closed forest in the Early Eocene to a more open environment with reedmarsh and wooded patches by the end of the epoch.     

河南潭头、卢氏和灵宝盆地上白垩统一下第三系的划分

在这篇短文中,根据脊椎动物化石的发现,进一步叙述和讨论了豫西潭头、灵宝和卢氏三个盆地的中、新生代地层的划分问题。在这三个盆地的中、新生代堆积物中,属于晚白垩世的有潭头盆地秋扒组和灵宝盆地的南朝组,后一个盆地还可能存在着时代更早的白垩纪地层。在潭头盆地的高峪沟组和大章组中分别找到中古新世的阶齿兽、中兽科和晚古新世的牧兽科、假古猬科化石;在潭头组中发现原恐角兽类和古脊齿兽类化石,时代为早始新世。在灵宝盆地的项城群中尚未找到哺乳类化石,可能包括古新世和始新世早中期的堆积。卢氏盆地的卢氏组和锄钩峪组以及灵宝盆地的川口组和浑水河组的时代为晚始新世。卢氏组下部和川口组或许可延至中始新世。     

Paleocene reefs on the Maiella Platform Margin, Italy: An example of the effects of the cretaceous/tertiary boundary events on reefs and carbonate platforms

Summary Reef facies, reef types and their biotic associations in the Maiella platform margin (central Italy) provide qualitative evidence for a significant reef decline across the Cretaceous/Tertiary (K/T) boundary, and indicate two phases of reef recovery during the Paleocene. Rudists dominated the reef community until the latest Cretaceous. A significant sea-level fall around the time of the K/T boundary is documented by a truncation surface associated with emersion. During sea-level highstands in the Danian to Early Thanetian and, more extensively, during the Late Thanetian, coral-algal patch-reefs grew along the platform margin and top. Already in the Danian to Early Thanetian, the reef communities were more diverse and the constructional types more evolved than previously known from this time. Differences between the Danian to Early Thanetian coral association, the Late Thanetian association, and Late Cretaceous coral faunas may have ecological or evolutionary causes. Repeated emergence produced a complex diagenetic history in the Danian to Lower Thanetian limestones. All Paleocene reefs were displaced by gravitative redeposition. Coral-algal reefs are less important in the Early to mid Eocene, when alveolinid foraminifera dominated on the Maiella shelf. Reefs on the Maiella platform diversified and attained large sizes in the Late Eocene to Early Oligocene, as known from other Mediterranean platforms. The external controls on the Late Cretaceous to Oligocene evolution and demise of reef communities that are most easily demonstrated with our data are sealevel fluctuations and climate change. We propose that the change in reef biota and reef types across the K/T boundary and during the Early Tertiary were important causes of the parallel changes in platform growth style.     

Paleogene terrigenous (flysch) sequences in Etoloakarnania region (W. Greece). Plankton stratigraphy and paleoenvironmental implications

Based on calcareous nannofossils and planktonic foraminifera1 biostratigraphic data from flysch sequences, we give evidence for the paleoenvironmental evolution of Gavrovo and Ionian foreland basins (External Hellenides, Etoloakarnania region). Our data suggest that the onset of clastic sedimentation in both foreland basins in the study area is chronostratigraphically placed at Late Eocene (from 36.2-34.4 Ma; nannofossil biozones NP19-20, planktonic foraminifera biozones P16-17). During the earliest Oligocene (NP21-22 nannofossil biozones/34.4-32.45 Ma), both basins represent restricted accumulation of sediments, mainly composed of clays and silts. The presence of thick flysch deposits, accumulated during Early Oligocene (33.4-30 Ma, nannofossil zone NP23), indicates an increasing rate of sediment supply. The flysch sequences in the Ionian basin are associated with a distal depositional environment, while in the same time the sedimentation in the external part of Gavrovo basin is related to a more proximal environment that is gradually deepening. On the contrary, the internal part of Gavrovo basin is characterised by deep-water facies, deposited in the Early Oligocene. At the end of Early Oligocene and the onset of Late Oligocene (nannofossil zone NP24/30-27.2 Ma, planktonic foraminifera zone P21), the deposition of coarse grained sediments in both basins indicates a shift to shallower depositional environment. The accumulation of fine-grained sediments during Late Oligocene (27.2-23.2 Ma, NP25 nannofossil biozone) in the Ionian basin marks the youngest flysch sediments in the Etoloakarnania region and specifies the time of the Gavrovo nappe emplacement on the Ionian zone. Moreover the emplacement of Pindos nappe on the Gavrovo zone is estimated between 30-27.2 Ma (NP24 biozone) as supported by the nannofossil analysis of samples in front of Pindos thrust.     

Lizards of the family Arretosauridae Gilmore, 1943 (Iguanomorpha, Iguania) from the Paleogene of Mongolia

The family Arretosauridae is an enigmatic group of Asian iguanians, which contains one species, Arretosaurus ornatus Gilmore, 1943 from the Late Eocene of Inner Mongolia (China). In this work, the fossil family is classified within the taxon Iguanomorpha (Iguanidae sensu lato) and supplemented with three new forms from the Middle Eocene and Early Oligocene of Mongolia and the previously described Hemishinisaurus latifrons from the Late Eocene of China, which was originally assigned to Anguimorpha (Xenosauridae). New data characterize Arretosauridae as an important element of the Paleogene herpetofauna of Asia.     

临夏盆地的新生代地层及其哺乳动物化石证据

临夏盆地的新生代地层相当发育 ,保存了从渐新世至全新世的连续沉积序列。更为重要的是 ,这些沉积物中含有丰富的哺乳动物化石 ,为划分和对比临夏盆地的新生代地层提供了可靠的证据。然而 ,此前关于这个盆地地层层序和时代的认识有许多矛盾之处 ,地层命名繁复 ,化石证据混乱。近年来我们对临夏盆地的野外考察已理清了沉积序列 ,并在充分的哺乳动物化石证据的基础上重新厘定了各个岩石地层单位所对应的地质时代。临夏盆地的新生代哺乳动物化石以晚渐新世的巨犀动物群、中中新世的铲齿象动物群、晚中新世的三趾马动物群和早更新世的真马动物群最为丰富。     

Early Tertiary fossil plants and paleoclimate of Lanzhou Basin

Fossil plants from the lower part of Xianshuihe Formation in the Lanzhou Basin, Gansu Province were studied. The flora contains 29 species, representing 20 genera and 12 families, which include Lauraceae ( Daphnogene ), Lardizabalaceae ( Akebia ), Berberidaceae ( Berberis ), Ulmaceae ( Planera, Ulmus, Zelkova ), Betulaceae ( Alnus, Carpinus ), Myricaceae( Myrica ), Salicaceae ( Populus, Salix), Myrsinaceae(Ardisia), Rosaceae ( Prunus, Sorbus, Sorbaria, Spiraea ), Leguminosae ( Gleditsia, Sophora), Anacardiaceae (Rhus), Caprifoliaceae(Viburnum). An analysis of the floristic elements and their foliar physiognomy shows that most members of the flora are deciduous broad-leaved trees or shrubs with a few evergreen shrubs. The most noteworthy species is Rhus turcomanica which was present in the Middle Eocene to Late Eocene of Central Asia (Kazakhstan, Turkmenistan). Generally, Rhus turcomanica occurred at the same beds as Palibinia, an extinct fossil plant whose presence indicates a subtropical dry climate. Another species, Sorbaria callicomifolia Kornilova was present from the Early Oligocene to Early Miocene of Central Asia (Kazakhstan and Turkmenistan). According to an analysis of spores and pollen, this flora contains over 20 species. It is predominated by the angiosperm pollen. There appeared Ephedripites and Nitrariadites which were important elements in the dry area. Ephedripites was found from the Upper Cretaceous to Early Tertiary. Nitrariadites occurred in the Late Miocene, whereas Rhus turcomanica and Sorbaria callicomifolia were both reported in the subtropical dry area from the Middle Eocene to Early Oligocene. The latest record of Rhus turcomanica is from the Middle Eocene to Early Oligocene of Central Asia. The presence of this element in the lower part of Xianshuihe Formation may indicate that itsage is the latest stage of the Early Oligocene.     

兰州盆地早第三纪植物及古气候意义

化石采自甘肃省兰州盆地咸水河组底部,经研究认为有29种,归属20属12科。它们是：樟科 Lauraceae (Daphnogene),木通科Lardizabalaceae(Akebia),小檗科Berberidaceae(Berberis),榆科Ulmaceae (Planera,Ulmus,Zelkova),桦木科Betulaceae(Alnus,Carpinus),杨梅科Myricaceae(Myrica),杨柳科Sali- caceae(Populus,Salix),紫金牛科Myrsinacese(Ardisia),蔷薇科Rosaceae (Prunus,Sorbus,Sorbaria,Spir- aea),豆科Leguminosae(Gleditsia,Sophora),漆树科 Anacardiaceae(Rhus),忍冬科Caprifoliaceae(Viburnum) 等。经植物区系组成与叶相分析显示,该植物区系的大多数成员是落叶阔叶乔、灌木,少数为常绿灌木。其中特殊的分子是 Rhus turcomanica Korov．ex Vassilvesk,该成分是早第三纪中、晚期的标志化石植物。另一化石植物 Sorbaria callicomifolia Kornilova曾出现在中亚的早渐新世,最晚至早中新世。同一层位采集的孢粉样分析结果显示：该组合仅约20种,种类相对贫乏,并以被子植物的花粉占优势。其中出现裸子植物的麻黄粉,被子植物的白刺粉及蒿粉等,这几个类型均指示沉积时期经历干旱气候。综合植物大化石及孢粉分析研究,均出现一些指示气候为亚热带干旱或周期性干旱气候的特点,并据Rhus turcomanica出现的最晚记录,推测咸水河组底部的地质时代大约是早渐新世晚期。     

L’origine et l’histoire évolutive des Cétacés

Cetaceans are the most highly modified mammals. They originate among terrestrial ariodactyles during the Early Eocene. The oldest known cetacean is Pakicetus, a terrestrial and cursorial taxon of the Early Eocene (50 Ma), which entered the water in search for food or, possibly, to protect its skin from the sun. A few million years later, Ambulocetus is an amphibious cetacean capable of moving on land but also an agile swimmer using its hind limbs for propulsion. Ambulocetus was a formidable predator with powerful teeth. The nares of Pakicetus and Ambulocetus were anteriorly placed, at the apex of the snout. During the Late Eocene, there appeared the first strictly aquatic cetaceans, the Basilosauridae. Their hind limbs are totally atrophied and are not functional. The nares are on the dorsal face of the rostrum on the anterior third of the skull. From that time, the way toward modern cetaceans was opened; the oldest mysticetes are from the Latest Eocene and the oldest odontocetes from the Early Oligocene.     

Deep-sea benthonic foraminiferal faunal turnover near the Eocene/Oligocene boundary

Eocene-Oligocene deep-sea benthonic foraminifera in D.S.D.P. Site 277 in the southwest Pacific have been analyzed to determine the benthonic foraminiferal response to the development of the psychrosphere near the Eocene/Oligocene boundary. Biostratigraphic ranges of 41 taxa show that 23 taxa are found throughout the Late Eocene to Early Oligocene sequence, while 18 taxa exhibit first or last occurrences. Comparison of the faunal changes in Site 277 with a benthonic foraminiferal oxygen isotope record shows that the development of the psychrosphere did not have a profound effect upon the benthonic foraminifera, and the overall faunal change preceding and subsequent to the bottom-water circulation event occurred gradually. The inferred water-mass event affected the relative abundance of one species, Epistominella umbonifera. The lack of major faunal changes at the Eocene/Oligocene boundary in Site 277 probably reflects either wide environmental tolerances of the benthonic foraminifera, or a bottom-water temperature change less than 3°C.Examination of previously published benthonic foraminiferal biostratigraphic data from D.S.D.P. Sites 167, 171, 357, 360, 363, and 400A, and deep-sea ostracode data from D.S.D.P. Leg 3 show faunal changes occurred during discrete intervals in the Middle Eocene-Early Oligocene. The faunal patterns from these data and from Site 277 show that the Eocene/Oligocene cooling event did not cause rapid, catastrophic changes of the benthonic faunas of the open ocean, although significant faunal changes are associated with the water mass event in Sites 167, 171 and 400A.The benthonic faunal changes in Middle Eocene-Early Oligocene time are consistent with the gradual decrease of inferred bottom-water temperatures, based on previously published oxygen isotopic data. The δ ¹⁸O Eocene/Oligocene enrichment of 0.76‰ is a major event in the Southern Ocean oxygen isotopic record, but is considerably less in magnitude than the 1.75-2.00‰ change that occurred gradually from mid-Early Eocene to the Eocene/Oligocene boundary. The benthonic foraminiferal and isotopic data indicate that bottom-water circulation may have developed during the Middle Eocene to Early Oligocene interval, with the 3°C bottom-water cooling near the Eocene/Oligocene boundary representing part of this development.     

Facies dynamics in Eocene to Oligocene circumalpine carbonates

A new concept, termed ‘Facies Dynamics’ (defined as changes of specific carbonate facies types in time and space, which are controlled by phylogenetic, ecological and geological parameters), is introduced. This concept aims to define and interpret spatial and temporal changes of carbonate facies patterns. It is based on Middle Eocene to Early Oligocene shallow-water carbonate facies types from the circumalpine area (north-eastern Italy, northern Slovenia, Austria and southern Bavaria), which are compared with respect to dominating biogenic components and their distributions along a shelf gradient. This comparison has lead to the distinction and definition of 14 Major Facies Types (MFTs), which are dominated by coralline algae, larger and smaller foraminifera, corals and bryozoans. The presence and distribution of these MFTs from three different time slices (Middle Eocene, Late Eocene and Early Oligocene) is compared. Nine aspects of facies dynamics are distinguished: origination, extinction, immigration, emigration, expansion, reduction, stasis, shift, and replacement of MFTs. These changes are controlled by regional changes in ecological parameters, but also by global events, especially extinction patterns at the Middle/Late Eocene boundary and at the Eocene/Oligocene boundary.     

Cenozoic deep-sea ostracods from Maud Rise, Weddell Sea, Antarctica (ODP Site 689): a palaeoceanographical perspective

Cenozoic palaeoceanography of the Maude Rise, Weddell Sea, Antarctica, has been investigated using Palaeocene to Quaternary deep-sea ostracod faunas from 23 samples of ODP Site 689. The abundance of ostracods is high enough only during the Palaeogene (Palaeocene-Oligocene) to allow palaeoceanographical inferences based on changes in diversity, dominance, endemism and faunal turnover (first and last occurrences). The abundance is particularly high throughout the Palaeocene and Eocene, but declines irreversibly near the Eocene/Oligocene boundary. The diversity increases more or less continuously from the Early Palaeocene to the Middle Eocene, and then it generally decreases throughout the remaining part of the Palaeogene (Middle Eocene-Oligocene); an exception is a positive peak in the Shannon-Weaver index in a single sample in the Late Oligocene. No positive peaks in diversity and taxa originations (first occurrences) at c. 40-38 Ma, occurs at Site 689; so the site provides no evidence for the establishment of the psychrosphere at this time. This corroborates similar regional results from an earlier study of benthonic foraminifera. Explanations for this may be related to Late Eocene-Early Oligocene changes in sedimentology and clay-mineralogy (associated with the progressive cooling of the Antarctica) which could have negatively affected abundance and diversity locally at Site 689. Alternatively, by this time, the ostracod fauna could also have been subjected to selective removal (with possible local extinction) of taxa (due to increased ventilation) or to thanatocoenosis dissolution (due to a decrease in temperature and availability of CaCO₃). A further possibility may be related to the fact that Site 689 was at intermediate water depths and may have remained within older water masses near the Eocene/Oligocene boundary. Failing these explanations, the results could indicate that the Late Eocene-Early Oligocene palaeoenvironmental changes in the world oceans were more gradual and occurred over a longer time interval than the global ostracod data show, at least at southern high latitudes.