New remains of Hyaenodontidae (Creodonta,Mammalia) from the Oligocene of Central Mongolia

New specimens of hyaenodontid creodonts are described which were unearthed in Mongolia by the Austrian–Mongolian Paleontological expeditions. Five taxa are identified: Hyaenodon eminus, Hyaenodon pervagus, Hyaenodon cf. incertus, Hyaenodon cf. mongoliensis, and cf. Hyaenodon gigas. Hitherto unknown morphological details are reported for most of these species. The implications to systematic of the species and the genus Hyaenodon are discussed. These Hyaenodon remains suggest a separate evolutionary lineage, with different species in Europe and Asia, even if the genus is also known from contemporary faunas of Europe and North America.     

Calcareous nannofossil biostratigraphy of the Cenomanian/Turonian boundary interval of ODP Leg 207 at the Demerara Rise

During Ocean Drilling Program Leg 207 at Demerara Rise (western tropical Atlantic) expanded sections of organic-rich laminated shales of late Cretaceous age, including the Cenomanian/Turonian boundary interval (CTBI) were recovered. These sediments yield rich assemblages of calcareous nannofossils, offering a unique possibility to calibrate the stable carbon isotope curve (δ¹³C_org). The calcareous nannofossils of Sites 1258, 1259, 1260 and 1261 have been investigated in order to gain a detailed biostratigraphic framework for the CTBI in the tropical latitudes. The bioevents observed have been correlated with the characteristic δ¹³C_org excursion of the CTBI. The events occurring during the excursion, and slightly below and above it, include the first occurrences of the calcareous nannofossil species Cylindralithus biarcus, Quadrum gartneri, Quadrum intermedium, Eprolithus octopetalus, Eprolithus eptapetalus, Eiffellithus eximius and the last occurrences of Corollithion kennedyi and Axopodorhabdus albianus. These bioevents have been correlated with those of other biostratigraphically and chemostratigraphically studied CTBI sections.     

New xylological data and the biogeography of the Iberian Peninsula during the Early Cretaceous

The position of the Iberian Peninsula during the Early Cretaceous, sandwiched between Laurasia and Gondwana, makes it an important area for the biogeography study of terrestrial ecosystems. Relevant data are, however, scarce. The discovery of silicified wood in the west of the Cameros Basin, in the village Hacinas (Spain), is the first record of the genus Protopodocarpoxylon in Spain and the seventh of Agathoxylon. A new species, Protopodocarpoxylon haciniensis sp. nov., is described. The anatomy of the samples studied shows that paleoclimatic conditions during the Early Cretaceous in the western part of the Cameros Basin were favorable to tree growth, with good water supply during the growth season. Although much impoverished in comparison with Western Europe, the Iberian Early Cretaceous wood floras are clearly Laurasian in affinity.     

Benthic foraminiferal assemblages of the Cretaceous platform carbonate succession in the Yavca area (Bolkar Mountains, S Turkey): biostratigraphy and paleoenvironments

The microbiostratigraphic analysis of the three outcrop sections from the Cretaceous inner platform carbonate succession in the Yavca area (Bolkar Mountains) allows to recognize the four local benthic foraminiferal zones. These are: (1) Voloshinoides murgensis and Praechrysalidina infracretacea Cenozone in the Lower Aptian; (2) Pseudorhapydionina dubia and Biconcava bentori Cenozone in the Middle-Upper Cenomanian; (3) Ostracoda and Miliolidae Interval Zone in the probable Turonian, represented by dolomitized limestones without any significant markers; (4) Moncharmontia compressa and Dicyclina schlumbergeri Cenozone in the Coniacian-Santonian. The benthic foraminiferal assemblages correspond to those in other areas of the Mediterranean realm, with the exception of a lack of alveolinids and orbitolinids due to unfavorable environmental conditions (inner platform, restricted shelf). After the regionally well-known emergence during the late Aptian, Albian and early Cenomanian, very shallow subtidal to intertidal conditions were re-established during the middle-late Cenomanian time. The Coniacian-Santonian benthic foraminiferal assemblage shows an increase in diversity and abundance as a result of open marine influence, confirmed by the presence of larger foraminifera (Dicyclina), Rotaliidae and radiolitid fragments. Thaumatoporella and Aeolisaccus-bearing wackestone intercalations still indicate the existence of sporadic restricted environment conditions. The Cretaceous shallow-water platform carbonate succession of the Yavca area is conformably overlain by gray pelagic limestones with calcispheres and planktonic foraminifera. The Campanian flooding of the Bolkar Da? carbonate platform resulted in drowning of the pre-existing biota and facies.     

Tethyan uppermost Permian (Dzhulfian and Dorashamian) foraminiferal faunas and their paleogeographic and tectonic implications

The foraminiferal faunas and biostratigraphic correlation of the Tethyan uppermost Permian (Dzhulfian and Dorashamian) provide important paleogeographic and tectonic data for the interpretation of the Palaeofusulina-bearing terranes in East and Southeast Asia. These interpretations have a significant bearing on understanding Japanese pre-Cretaceous tectonostratigraphic and micropaleontologic data, as well as the geodynamic evolution of the Japanese Palaeofusulina-bearing terranes. The Tethyan foraminiferal fauna in the uppermost Permian is characterized by the occurrence of provincial and endemic schubertellid genera, and the absence of neoschwagerinids and verbeekinids which had characterized the rapidly evolving Middle Permian Tethyan marine faunas until their extinction at the end of the Midian. Difficulties in world-wide correlation of the uppermost Permian have resulted because of different geographic faunal compositions and the geographic patterns of extinction of Permian marine faunas. The Palaeofusulina fauna is one of the most reliable indicators of the uppermost Permian. Its presence or absence serves as paleogeographic constraints on East and Southeast Asian terranes. For example, the absence of Palaeofusulina fauna and the presence of late Midian Lepidolina multiseptata faunas in the Lhasa Terrane in Tibet and the Wolya Terrane in Sumatra (the third continental sliver north of Gondwana) are important, particularly, for identifying the rift–drift–collision process of the Gondwana-affinity terranes. They suggest a Late Permian separation of the two terranes from Gondwana. Tethyan Palaeofusulina occur in the latest Permian tropical to subtropical latitudinal belt and along with other geologic data assist in paleogeographic reconstructions and in interpreting the possible movement and emplacement of the Palaeofusulina-bearing terranes such as the Maizuru, South Kitakami–Kurosegawa and Chichibu terranes in Japan. They reveal that: (1) the Upper Permian Maizuru Group was deposited on the eastern continental margin of South China; (2) the occurrence of the Lower Permian Cathaysian flora and a number of geologic data in the South Kitakami–Kurosegawa suggest an arc–trench system setting and the Late Permian deposition in a shallow open-marine environment in proximity to South China; (3) foraminiferal biogeograpic data and the reconstructed oceanic plate stratigraphy in the Chichibu Terrane constrain the location of the Chichibu Seamount Chains to the western part of the Panthalassan domain, as they moved westwards against the Cathaysian Continent until their Jurassic accretion.     

Biostratigraphie des brachiopodes et âge carixien (Pliensbachien inférieur) des calcaires à grands bivalves en Algérie occidentale

Recent researches on the Lower Jurassic of Western Algeria allow to establish a lithostratigraphic standard correlating the different members and formations developed in the Ouarsenis and Tlemcen Mountains, the Oran High Plains, the Nador and Ksour Mountains. The position of the large bivalve limestones (= Lithiotis limestones) is well established in the different lithologic successions. This facies is widespread in Western Algeria where it is interbedded with brachiopod marker beds, indicating short periods of maximum flooding. The large number of collected brachiopods are distributed into four “faunas” (assemblages) ranging from the Late Sinemurian (= Lotharingian) to the Early Pliensbachian (= Carixian). These faunas have been dated by the age of the species that they have in common with the NW european and western tethyan provinces. These chronological data are confirmed by rare ammonites. All these results evidence the age of the large bivalve facies in Western Algeria. They are contained in the Middle to Late Carixian (Demonense and Dilectum Zones). This datation is in conformity with that known from the Eastern High-Atlas (Bou Dahar). Consequently, the large bivalves cannot be considered as “markers for the unique Domerian” as it has been too often asserted. The palaeontological part of our study shows that the multicostate Zeilleriids (several Tauromenia species from the Late Sinemurian to the Early Carixian) are older than the multicostate Terebratulids (Hesperithyris species from the Middle to Late Carixian).     

A new orthoceratoid cephalopod from the Ordovician (Caradoc) of east-central Iran

Orthoconic cephalopods from the Ordovician Katkoyeh Formation at Banestan, Kerman Province, Iran, comprise a single species named as Sactorthoceras banestanensis Evans nov. sp. Associated faunas suggest close palaeobiogeographical linkage with other regions of north peri-Gondwana, notably Morocco and Bohemia (Perunica), while Sactorthoceras itself is also indicative of relationships with Baltica and the Sino-Korean Plate.     

Biostratigraphy and palaeobiogeography of Lower Permian (lower Kungurian) conodonts from the Tak Fa Formation (Saraburi Limestone), Thailand

Lower Permian (lower Kungurian) conodonts are reported from the Indochina Block of Southeast Asia. The fauna from the Tak Fa Formation of the Saraburi Limestone Group exposed in limestone hills NNW of Khok Samrong, Thailand, includes Sweetognathus subsymmetricus Wang, Ritter and Clark (early forms) and Pseudosweetognathus costatus Wang, Ritter and Clark. The co-occurrence of these species indicates a Lower Permian age (upper half of the lower Kungurian) for the sampled limestones representative of the Mesogondolella siciliensis–S. subsymmetricus Zone of South China. Sweetognathus and Pseudosweetognathus are for the first time reported from the Indochina terrane located in the palaeoequatorial belt in the Kungurian. Pseudosweetognathus appears restricted to the Kungurian of the South China and Indochina terranes thus supporting palaeogeographic reconstructions that isolate these terranes within the Palaeo-Tethys during the Kungurian.     

Middle Permian ostracod fauna from the Khao Khad Formation (Indochina Terrane), Central Thailand

Permian ostracods are reported for the first time from the Wordian (Middle Permian) Khao Khad Formation of Saraburi Group (Lopburi Province, Central Thailand). The ostracod fauna consists of 18 species belonging to 11 genera including Bairdia, Bohlenatia, Liuzhinia, Silenites, Acratia, Bairdiacypris, Basslerella, Aurigerites, Microcheilinella, Paraparchites and Shemonaella. The studied Khao Khad Limestone, which are rich in fusulinids, gastropods, ostracods, bivalves and brachiopods, was deposited in a shallow carbonate platform on the western margin of the Indochina Terrane. The ostracod assemblage is typically Palaeo-Tethyan and similar to faunas from the other Lower to Middle Permian limestones in central Thailand.     

Revidierte Systematik der Ostracoden im Oberjura und der basalen Kreide Ostdeutschlands

The Upper Jurassic and basal Cretaceous ostracod faunas of Northeastern Germany, which have not been sufficiently investigated and documented yet, are revised. The fauna, documented by stratigraphical tables and SEM-pictures, consists of 116 species from 36 genera, two species of which are new:Galliaecytheridea wienholzae n. sp. andRasthalmocythere keuppi n. sp. The biostratigraphical ränge of the taxa extends from the Oxfordian to the early Berriasian. A palaeobiogeographical correlation with the ostracod faunas of Northwestern Germany reveals close relationships between both areas concerning the stratigraphical range and assemblage of the fauna.     

J. Deprat,l’Eubée (Grèce) et les fossiles introuvables

In Evia (Greece), limestones attributed to the lower Cretaceous by J. Deprat are in fact of Triassic to Upper Jurassic age. These erroneous attributions are based on the allegedly presence of Barremian and Albian fossils and on the supposed progressive passage of these limestones to the Cenomanian ones. Generally, except for the upper Cretaceous rich in Rudists and known since older works, a big part of the stratigraphical attributions of J. Deprat in Median Evia are erroneous.     

Analysis of the factors that affect the distribution and abundance of three Neobuxbaumia species (Cactaceae) that differ in their degree of rarity

We studied three species of columnar cacti in the genus Neobuxbaumia which differ in their degree of rarity: Neobuxbaumia macrocephala (the rarest), Neobuxbaumia tetetzo (intermediate), and Neobuxbaumia mezcalaensis (the most common). To investigate the ecological factors that limit their distribution and abundance, we surveyed 80 localities within the region of Tehuacan-Cuicatlán, in Central Mexico. At each locality we measured several environmental variables, and the density of the Neobuxbaumia populations present. We used a principal component analysis (PCA) to identify the factors that are associated to the presence/absence of each species. Additionally, we carried out multiple regressions between environmental variables and population density to test whether the variation in these variables was related to changes in abundance. The results show that factors significantly affecting the distribution of these species are mean annual temperature, altitude, rainfall, and soil properties such as texture and organic matter content. N. mezcalaensis reaches maximum population densities of 14,740 plants per ha (average density = 3943 plants per ha) and is associated with localities with relatively abundant rainfall. N. tetetzo shows maximum population densities of 14,060 plants per ha (average = 3070 plants per ha), and is associated with sites located at high latitudes and with high phosphorous content in the soil. The rarest species, N. macrocephala, shows maximum densities of 1180 plants per ha (average = 607 plants per ha) and is associated with localities with high soil calcium content. The distribution of this species is limited to sites with specific values of the environmental variables recorded, conferring it a high habitat specificity which accounts for its rarity.     

Vent and mound rugose coral associations from the Middle Devonian of Hamar Laghdad (Anti-Atlas, Morocco)

Peculiar associations of small, solitary, deep-water rugose corals are described from the Middle Devonian buildups situated in the easternmost part of Hamar Laghdad area of southern Morocco. The most of them are monospecific and consist of simplified taxon “Amplexus” florescens but one is polyspecific and composed of specimens belonging to four different species representing three families. These rugosan associations form isolated nest-like aggregations where numerous densely packed specimens are arranged mostly in life position. The polyspecific and two monospecific associations are interpreted as growing in close proximity to venting fields. They reveal a unique “calice-in-calice” recolonization pattern expressed by successive settlement of juvenile specimens in the calice of dead individuals. This pattern was presumably a consequence of selective survival of coral larvae settling in extreme vent habitats. Although, the “calice-in-calice” pattern is common in both, mono- and polyspecific associations, there are differences expressed in the character of larval attachments and various types of the calice fillings. The trophic interaction between corals and ostracods is discussed. Additionally, associations of “Amplexus” florescens, not displaying “calice-in-calice” pattern of growth have been found within the mound where polyspecific association occurs. These are interpreted as growing away from venting fields. Comparisons of Amplexus-type coral faunas with the other North African and European corals allow the classification of these ampleximorph rugosan taxa as characteristic biotic components of the Middle Devonian mound environments influenced by venting activity. Two new genera and species, Weyeraia prima and Vesiculolasma erfoudi, are introduced.     

Ophiuroid remains from the Toarcian of Sainte-Verge (Deux-Sèvres, France): paleobiological perspectives

The Toarcian sediments exposed at Sainte-Verge (Deux-Sèvres, France) are especially rich in echinoderm remains. The present paper describes and illustrates the ophiuroids. On the basis of lateral arm plates, 13 species are distinguished, including two new ones: Sinosura fasciata sp. nov. and Sinosura extensa sp. nov. Most of the recognized species have been recorded previously from the Late Toarcian and Aalenian in Germany and, to a lesser extent, from the late Early Jurassic of England and Switzerland. High similarities between the faunas of northwest Europe suggest a boreal provincialism of ophiuroids. The recognition of 13 species is comparable to the diversity known from other stratigraphic levels (Jurassic and Cretaceous) or in the richest stations of recent oceans. The species association of the Toarcian of Sainte-Verge, with two Ophiolepididae, one Ophiacanthidae, four Ophioleucidae, two Ophiodermatidae, two Ophiuridae, and one Hemieuryalidae may be compared with species associations of recent shelf, offshore environments. Such persistence of components of diversity and ecological affinities of species suggests strong evolutionary conservatism of the ophiuroids, after a rapid radiation during the earliest Jurassic. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.     

Age of the latest marine sedimentation in the western Kunlun area constrained by planktic foraminifera

Surface uplift of the Tibetan Plateau in the Cenozoic has dramatically affected evolutions of climate, environment, and biota in East Asia. The onset time of plateau uplift can be roughly constrained by the termination of the latest marine sedimentation, which shows large spatial differences in the Tibetan Plateau. In the northwest Tibetan Plateau of the western Kunlun area, the Tielongtan Group represents the latest marine sedimentation. However, the age of its depositional cessation is still unknown. For the first time, we conduct taxonomic, paleoecologic and paleogeographic studies of planktic foraminifera in the limestones of the Tielongtan Group. Despite poor preservation and low abundance, ten planktic foraminiferal species are identified, including Globotruncana falsostuarti, G. cf. linneiana, G. cf. ventricosa, Planohedbergella prairiehillensis, P. cf. yaucoensis, Pseudotextularia nuttalli, Planoheterohelix globulosa, P. cf. praenuttalli, Muricohedbergella holmdelensis and Whiteinella brittnensis. The foraminiferal assemblages suggest an age of late Campanian to Maastrichtian, indicating a shallow, neritic marine environment. Combining available research data from other regions, we show that these planktic foraminifera were widely distributed in the Tarim basin, southern Tibet, and the Mediterranean area during the latest Cretaceous. Our result of planktic foraminifera in the Tielongtan Group implies that the surface uplift of the western Kunlun area did not begin until after ∼76–66 Ma.     

Sur l'origine du genre Microceratina Swanson, 1980 (Ostracoda, Eucytherurinae) et sa présence téthysienne dès le Jurassique supérieur

The discovery in the uppermost Jurassic of Lebanon of a species of the ostracod genus Microceratina Swanson, 1980 (Eucytherurinae), of which the oldest known species was until now of Maastrichtian age, confirms the Tethyan origin of this genus. Two new species are created: Microceratina bhannesensis nov. sp. from the Upper Jurassic (Kimmeridgian) of Lebanon, and Microceratina azazoulensis nov. sp. from the Cenomanian of Morocco. The genera Chapmanicytherura Weaver, 1982 and Erratacytheridea Herrig et al., 1997, are considered as probable junior synonyms of Microceratina. An exhaustive bibliographical analysis allowed to identifying several other Cretaceous species susceptible to be assigned to the genus Microceratina.     

Anisian foraminifers from allochthonous limestones of the Tanoura formation (Kurosegawa Terrane, West Kyushu, Japan)

Thirty-five species belonging to 21 genera of foraminifers are distinguished from allochthonous limestone blocks contained within the autochthonous mudstones and sandstones of the Carnian Tanoura Formation, Kurosegawa Terrane of West Kyushu (SW Japan). These blocks are considered to be Anisian in age, based on the occurrence of two foraminifers widely distributed in the Anisian of the Tethyan Realm, Pilammina densa and Meandrospira dinarica; they are associated with Involutinid-like forms, such as Triadodiscus and Aulotortus, and with other foraminifers. The allochthonous limestones are mostly composed of oolites, abundant bioclasts and detrital quartz grains. They are thought to have been redeposited during the Carnian on the shelf slope of the South Kitakami-Kurosegawa Old Land. Palaeogeographically, this terrane was part of the North Gondwana margin, then isolated eastwards before its Early Cretaceous amalgamation with South China. Three foraminiferal species, Triadodiscus eomesozoicus (Oberhauser), Triadodiscus? tanourensis, n. sp., and Triadodiscus? sp. are described from the Anisian allochthonous blocks.     

Caradoc strophomenoid and plectambonitoid brachiopods from Wales and the Welsh Borderland

Abstract: Ordovician strophomenoidean and plectambonitoidean brachiopods are reviewed and partially redescribed from the Caradoc (Sandbian to Early Katian) age rocks of Wales and the Welsh Borderland of England, then forming part of the Avalonia Terrane. There are 51 nominal species available, of which 12 are synonymised here and many transferred to different genera. Strophomenoids occurred sporadically, often rarely but occasionally abundantly, particularly in mid‐shelf benthic assemblages, and 21 named species and subspecies are noted, including the new Kiaeromena (Kiaeromena) harperi, as well as six in open nomenclature. The common genus Kjaerina, with six species known from the area, is revised in detail. In contrast to the strophomenoids, plectambonitoids were more common in shallow and mid‐shelf assemblages, including Eoplectodonta (Eoplectodonta) abigailae sp. nov., with Sowerbyella in particular dominating many bedding planes, and 17 named species are reviewed, as well as three in open nomenclature. The distinctive Gunningblandella, hitherto known only from Australia and Kazakhstan, is recorded for the first time from Europe. The Avalonian strophomenides are compared with those from neighbouring terranes, particularly Laurentia and Baltica, during a time when the seas between those terranes were narrowing, and the faunas from the three terranes are found to be largely similar at the generic level, although there are few species in common. In contrast, there are few genera in common between those three terranes and the Mediterranean Province of Northwestern Gondwana.     

New and poorly known acrotretid brachiopods (Class Lingulata) from the Cedaria-Crepicephalus zone (late Middle Cambrian) of the Great Basin, USA

Seven new late Middle Cambrian (Cedaria-Crepicephalus zone) acrotretid species are described from the Great Basin, USA. The species belong to five genera of which Lensotreta is new. The following new species are described: Anabolotreta? glabra, Anabolotreta mogota, Canthylotreta crista, Dactylotreta elegantula, Lensotreta perplexa, Opisthotreta transversa, and Opisthotreta indistincta. The shell structure of Canthylotreta is described for the first time based on new material of the type species Canthylotreta marjumensis and of the new species C. crista. The shell of Canthylotreta includes two types of shell fabric, camerate and columnar. Moreover, parts of the shell show transitional textures, supporting the view that the camerate shell structure may has originated from a columnar fabric. Picnotreta lophocracenta Robson and Pratt, 2001, recently described from western Newfoundland, is also described from the new occurrence in the Great Basin.     

Lower Jurassic corals from the Pamir Mountains,Central Asia

The paper describes new Lower Jurassic corals from the South-Eastern Pamir Mountains (Tajikistan) and interprets their relationships with contemporaneous West Tethyan corals. Taxonomic similarities with Pliensbachian European and North African faunas indicate a Pliensbachian age for this fauna, which was previously considered to be of Hettangian/Sinemurian age. Together with the taxa earlier described from the Pamirs, this fauna consists of 30 species of 25 genera, including Triassic holdover genera such as Stylophyllopsis, Phacelostylophyllum and Eocomoseris. The bulk of the fauna represents new Jurassic genera: Alichurastrea, Eomicrophyllia, Guembelastreomorpha, Gurumdynia, Pinacomorpha, Protostephanastrea, Psenophyllia, Sedekastrea and Stylimorpha. Earlier coral studies of the region concerned the genera: Archaeosmilia Melnikova, 1975, Archaeosmiliopsis Melnikova, 1975, Cylismilia Roniewicz, 1988, Pachysmilia Melnikova, 1989, and Prodonacosmilia Melnikova in Melnikova and Roniewicz, 1976. Two species that were considered to belong to the genus Cylismilia, are redescribed and reclassified in the genera Psenophyllia, and Archaeosmilia Melnikova, respectively.