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1.
《Geobios》2014,47(1-2):31-38
A new calcareous nannofossil, Crepidolithus cantabriensis nov. sp., is described from the Lower Jurassic marls and marly limestones of the Cantabrian Range (Northern Spain). The new species is characterized by medium-sized, normal to narrowly elliptical coccoliths with open central-areas. In the light microscope, under crossed nicols and in distal view, it displays a characteristic bicyclic extinction pattern. Its inner rim edge shows maximum birefringence colours, which vary from white to yellow, whereas the faintly outer rim margin exhibits low birefringence, tending to grey, and they are separated by a dark and sigmoidal isogyre. C. cantabriensis nov. sp. seems closely related to Crepidolithus crassus on the basis of shared morphological characters. Both of them have a distal shield composed of around thirty sub-vertical, dextrally imbricating laths. The central-area width of C. cantabriensis nov. sp. is approximately half of the coccolith width, whilst it is reduced to one or two tiny lenticular slits in C. crassus. Nevertheless, the phyletic relationships between C. cantabriensis nov. sp. and Crepidolithus cavus are not clear, since they show different rim structures, and C. cavus has a delicate bar aligned along the minor axis of its central area. The first specimens of C. cantabriensis nov. sp. have been recognized within the Raricostatum AZ in the Tudanca section. This species seems to be more abundant in the Reinosa area, which occupied a more distal position with respect to the Iberian Massif during the studied time interval. It is hypothesized here that C. cantabriensis nov. sp. could have inhabited the lower-photic zone.  相似文献   

2.
《Comptes Rendus Palevol》2014,13(3):157-181
The Bavarian fissure filling Petersbuch 28 (Germany, Lower Miocene, MN 3/4) yielded a diverse assemblage of shrews. Soricella discrepans Doben-Florin, 1964 and Paenelimnoecus micromorphus (Doben-Florin, 1964) show bimodal size distributions in some dental elements, which is interpreted as the result of a small time averaging. Two upper incisor types of Miosorex desnoyersianus (Lartet, 1851) were found, also indicating two populations of slightly different times. Apart from these, the fissure yielded Heterosorex neumayrianus (Schlosser, 1887), the only heterosoricid present, Lartetium petersbuchense Ziegler, 1989, L. cf. prevostianum (Lartet, 1851) and Florinia stehlini (Doben-Florin, 1964). The shrews confirm that Petersbuch 28 represents a time period near the MN 3/MN 4 transition. Thus, it fills the gap between the classical localities of Wintershof-West and Petersbuch 2. The two species of Lartetium Ziegler, 1989 are possible immigrants.  相似文献   

3.
Middle to late Miocene calcareous nannofossil data of ODP Site 1085 from the eastern South Atlantic off Namibia were analysed to document spatial and temporal changes in surface-ocean circulation, upwelling initiation, and associated productivity.

Our data show that calcareous nannofossils constitute a significant part of the carbonate fraction throughout the investigated interval from 12.5 to 7.7 million years (Ma). Highest numbers of calcareous nannofossils (up to 38,000 × 106 nannofossils g− 1 sediment) were observed during the intervals 9.9 to 9.7 and 8.7 to 8.0 Ma. These elevated numbers of calcareous nannofossils may generally be linked to the initiation of upwelling at about 10 Ma in the studied region. In contrast, diminished numbers of calcareous nannoplankton, as in the interval 9.6 to 9.0 Ma, probably characterise time intervals of weaker productivity resulting in a decrease of nannofossil carbonate contents in the sediments of Site 1085. This decrease in nannofossil production could be one possible explanation for the major CaCO3 depression in between 9.6 and 9.0 Ma. Coccoliths of the genus Reticulofenestra are the most abundant taxa. Their occurrences are characterised by changes in the investigated time interval. In addition, Coccolithus pelagicus, Calcidiscus leptoporus and Umbilicosphaera spp. contribute a common part of the assemblage. Calcareous nannofossils account for more than half of the carbonate, with peak contribution up to 80% at 8.8 Ma.  相似文献   


4.
A new pearleye species of the alepisauroid family Scopelarchidae, Scopelarchoides neamticus sp. nov., is described herein based on two specimens from the Oligocene Lower Dysodilic Shales Formation, cropping out in the Pietricica Mountain, Romanian Eastern Carpathians. The new species described herein exhibits a unique combination of features (including head length about 25% of SL; coracoid remarkably expanded; both preorbital and postorbital lengths larger than orbit diameter; 50 or 51 vertebrae; dorsal fin with nine or ten rays; anal-fin with 28 rays; length of anal fin base about 30% of SL; preanal distance almost 60% of SL; pelvic fin insertion located just under the second dorsal fin ray; pectoral fins only slightly longer than pelvic fins; caudal fin with 19 principal rays plus 14 upper and 13 lower procurrent rays) that justifies its recognition as a new species of the genus Scopelarchoides. Both morphological and meristic features suggest a certain degree of similarity between S. neamticus sp. nov. and the extant species Scopelarchoides signifer. The fossils of the new Oligocene species described herein represent the oldest known skeletal record of Scopelarchidae.  相似文献   

5.
A new comparative study of the two crania, LGPUT RZO-03 and LGPUT RZO-68 attributed to Palaeoreas zouavei Bouvrain, 1980 from the Late Miocene of Axios Valley, Greece reveals great morphological and metric differences between them, which require the exclusion of LGPUT RZO-68 from this species and even from Palaeoreas Gaudry, 1861. This decision leaves unsupported many diagnostic features of P. zouavei applied by previous authors and along with recent data from Bulgaria put in doubt the validity of P. zouavei as a whole. As a result, the genus Palaeoreas is re-defined as monotypic and the cranial morphometric changes of P. lindermayeri (Wagner, 1848) are discussed on a temporal basis. An updated taxonomic analysis confirms the presence of P. lindermayeri in the Late Turolian mammal assemblage of Dytiko-1 (Axios Valley, Greece) but rejects its occurrence at Dytiko-2. Instead, a re-examination of old cranial specimens and a study of new ones suggest the presence in both sites of Majoreas Kostopoulos, 2004 a Late Miocene taxon previously mostly known from the eastern banks of the Aegean Sea. A reassessment of the LGPUT RZO-68 cranium, and its comparison with Palaeoreas and Criotherium Forsyth-Major, 1891, suggests that it deserves taxonomic distinction at genus and species levels: Stryfnotherium exophthalmon.  相似文献   

6.
Gaimanophis is an extinct boid genus represented so far by a single species (Gaimanophis tenuis) known by isolated vertebrae from the early Miocene of Patagonia. In this paper, a new species of Gaimanophis is described from the India Muerta Formation (late Miocene) of Tucumán province (Argentina). Gaimanophis powelli sp. nov. distinguishes itself from G. tenuis mainly in its larger size, prezygapophyses less slanting, neural spine shorter dorsally than ventrally, and zygosphene straight bearing an anteriorly protruding tongue. This record indicates a wider temporal and geographical distribution of the genus from the early Miocene of Patagonia to the late Miocene of northwestern Argentina. The recognition of a new species of boid in South America increases the known diversity of this group. Although boids have inhabited in this territory since the Paleocene, fossils belonging to the group only show a glimpse of the real past diversity in the continent.  相似文献   

7.
Gliridae's populations found i twelve quarry in theGers (from «Zone d'Estrepouy to «zone de Sansan) are described and figured in this paper. Their phyletic relations are precised and a paleoecological approach is suggested. One new taxa of provable lineage (Paraglis infralactorensis nov. sp.) is created.  相似文献   

8.
《Comptes Rendus Palevol》2019,18(6):589-597
Examination of fossil ant specimens from various private and institutional German collections of Baltic amber has revealed a new genus and species of Myrmicinae, described here as Thanacomyrmex hoffeinsorum gen. et sp. nov. The new worker morphotype shares some similarities with the coeval extinct genus Parameranoplus Wheeler, also from Baltic amber, and the extant genera Pristomyrmex Mayr and Acanthomyrmex Emery, suggesting placement of the new fossil in the Myrmecina genus-group within the tribe Crematogastrini. The new genus highlights the tremendous diversity of ants that evolved in the Palaeogene European forests and composed the first major radiation of crown-group ants.  相似文献   

9.
《Comptes Rendus Palevol》2014,13(8):647-664
The most updated stratigraphical distributions of the Cricetodontini from the Calatayud–Daroca Basin are presented. Cricetodon sansaniensis (local biozone F, MN6, middle Aragonian) and Cricetodon jotae (local biozone G1, G2 and G3, MN6-MN7/8, Middle–Upper Aragonian) from the middle Miocene are described and discussed. Generally, the genera of Cricetodontini were used to define large time intervals, whereas the species were neglected in the local biostratigraphical studies. The results presented herein show that, for the Calatayud–Daroca Basin, most of the stratigraphical distributions of the species of Cricetodontini are strongly linked with the local biozonation. That reveals that they could be used as good biostratigraphical indicators. Moreover, the unusually long local biozone G3 could be redefined and subdivided based on the distributions of the four species of Cricetodontini present in it. However, it is recommended to complete the study of the whole rodent fauna before proposing a new biozonation.  相似文献   

10.
The Ologe Lagoon in southwestern Nigeria is a natural habitat located closely to both residential and industrial estates. The lagoon is heavily affected by effluents of agricultural and industrial runoff including organochlorine compounds and heavy metals (chloropesticides, DDT and polychlorinated biphenyls, cadmium, manganese, zinc, copper, lead, iron and nickel). Ologe Lagoon is situated in a semi-isolated position and its brackish waters traverse several creeks and lagoons before it reaches the Atlantic Ocean. The lagoon experiences minor tidal but noticeable salinity and pH variations during the rainy season. During the dry season, however, the waters have a comparatively long resident time where sediments act as sink and aggregate contaminants over time. Investigations on benthic foraminifera, thecamoebian and diatom species were carried out to document the current status, composition, spatial distribution, and response of microfaunal assemblages to environmental stressors within the lagoon. The benthic foraminifer assemblage is composed of four highly specialized agglutinated species of Ammotium salsum, Miliammina fusca, Ammobaculites dilatatus and Ammobaculites aff. A. exiguus. They are present at all sample sites with varying abundances. The high abundance of Ammotium salsum is considered an indication of environmental stress. Thecamoebian species of Difflugia oblonga, Difflugia proteiformis and Pontigulasia compressa were also recorded in varying proportions and generally represent less than one percent of the total foraminifera/thecamoebian assemblage. The presence of marine brackish water larger siliceous diatoms of Actinoptychus and Campylodiscus species indicates an interaction between the lagoon and the marine waters although on the minimal scale with regards to actual salinity ranges. The faunal assemblages recovered are characterized by low species richness and alpha diversity indices and are typical of shallow, marginal-marine hyposaline environments. Numerical abundances and spatial distribution patterns suggest taxon-specific habitat preferences and highlight their potential for environmental monitoring studies.  相似文献   

11.
《Comptes Rendus Palevol》2013,12(5):257-267
In the soricid fauna of the Early Miocene Petersbuch 28 fissure fill from Bavaria, Germany, specimens of Miosorex desnoyersianus (Lartet, 1851) and Paenelimnoecus micromorphus (Doben-Florin, 1964) retain a tiny penultimate antemolar. This antemolar was previously unknown for P. micromorphus, because the tiny antemolar has not been preserved until now. Miosorex desnoyersianus retains the rudimentary tooth; its possible function was to keep the p4 in upright position. The younger species of Paenelimnoecus have lost this vestigial tooth. Based on the alveoli, Miosorex pusilliformis is interpreted as a junior synonym of Mdesnoyersianus, and the diagnoses of Miosorex desnoyersianus and Paenelimnoecus micromorphus are emended.  相似文献   

12.
The Pleistocene elevated marine carbonate complexes on Mauritius island correspond to three types of depositional zones: (1) reef-crest zone, (2) backreef zone, (3) littoral zone.On reef crests, the primary frame-builders are scleractinian corals (Acroporidae, Faviidae, Poritidae) and crustose coralline algae. The secondary builders are encrusting Foraminifers (Homotrematidae) chiefly, Molluscs (Vermetidae), Bryozoans (Cheilostomata) and Serpulids. Associated internal sediments are coarse to fine sand-sized grainstones or packstones and wakestones. In decreasing order of abundance, skeletal elements include fragments of corals, branched and crustose red algae, Pelecypods, Gastropods, benthonic Foraminifera (Amphisteginidae, Peneroplidae, Calcarinidae, Nummulitidae, Alveolinidae and Homotrematidae), Echinoderms and Alcyonarians; the most abundant mud-sized grains are identified as tunicate spicules. Primary marine cements are needle, palisade, micrite and pelletal ones.The backreef zone is characterized by coarse tomedium grainstones, packstones and wakestones. In addition to pellets the most common components are skeletal in nature; they broadly show the same mode of occurrence as the reef-crest unit. Primary cements locally occur in packed fibrous or micrite form.In littoral areas, well-sorted grainstones to poorlysorted mudstones can be described. The distribution of the various categories of biogenic particles is dependent upon the extent of reef tracts; ancient beaches from narrow reefs are characterized by coralgal facies while consolidated muddy banks in large complexes display high amount of molluscan detritus. Primary cementation appears mainly to be the result of the precipitation of fibrous or micrite calcite.The morphology, biological associations andsediments of these Pleistocene limestones are homologous with those of the adjacent modern environments.  相似文献   

13.
A new large representative of the Anseriformes, Garganornis ballmanni n. gen. et n. sp., from the Miocene of Gargano, Italy, is described from the distal end of a left tibiotarsus. G. ballmanni displays morphological features that are characteristic of the Anseriformes, but differs from all extant and fossil Anseriformes, as well as from taxa closely related to Anseriformes. G. ballmanni is characterized by a very wide and shallow fossa intercondylaris, a less pronounced difference in width of the lateral and medial condyle, reduced epicondyli, and a circular opening of the distal canal. G. ballmanni is larger than any living member of Anseriformes, and with an estimated body mass between 15.3 and 22.3 kg, it was most likely flightless. Although the observed similarities between G. ballmanni and basal taxa might indicate that G. ballmanni represents an insular relict of a stem lineage, it is considered more likely that G. ballmanni was a species of waterfowl highly adapted to a terrestrial lifestyle in an insular environment where mammalian carnivores are rare.  相似文献   

14.
Clarifying morphological variation among African and Eurasian hominoids during the Miocene is of particular importance for inferring the evolutionary history of humans and great apes. Among Miocene hominoids, Nakalipithecus and Ouranopithecus play an important role because of their similar dates on different continents. Here, we quantify the lower fourth deciduous premolar (dp4) inner morphology of extant and extinct hominoids using a method of morphometric mapping and examine the phylogenetic relationships between these two fossil taxa. Our data indicate that early Late Miocene apes represent a primitive state in general, whereas modern great apes and humans represent derived states. While Nakalipithecus and Ouranopithecus show similarity in dp4 morphology to a certain degree, the dp4 of Nakalipithecus retains primitive features and that of Ouranopithecus exhibits derived features. Phenotypic continuity among African ape fossils from Miocene to Plio-Pleistocene would support the African origin of African apes and humans (AAH). The results also suggest that Nakalipithecus could have belonged to a lineage from which the lineage of Ouranopithecus and the common ancestor of AAH subsequently derived.  相似文献   

15.
16.
《Comptes Rendus Palevol》2019,18(7):817-847
Excavations in the locality Gritsev (karstic fillings of the upper Miocene age in a limestone quarry in Shepetovsky District, Khmelnitsky Region, Ukraine) revealed, since 1983 when excavations started, a rich vertebrate fauna that includes also amphibians and lizards. The material is rich enough to assess individual and developmental variation within some taxa (e.g., Pseudopus pannonicus). Although the fragmentary nature of the disarticulated bones does not sometimes allow precise taxonomic assignment, morphological differences in, e.g., dental characteristics suggest the presence of some other ones, not formally named forms. Thus, the list of the amphibian and reptilian taxa from Gritsev is by far not complete, but their osteological characteristics are representative to such a degree that they can provide information for comparisons with other European Miocene herpetofaunas.  相似文献   

17.
《Annales de Paléontologie》2017,103(2):113-125
The first known fossil specimens of pipehorses (Haliichthyinae) were unearthed from the Middle Miocene (Sarmatian) beds of the Coprolitic Horizon in the Tunjice Hills, Slovenia. These fossil pipehorses belong to a new genus and species Hippohaliichthys edis, which was similar to the extant species Haliichthys taeniophorus. The body morphology indicates that the described fossil pipehorses were also closely related to the pygmy pipehorse Hippotropiscis frenki and the seahorse Hippocampus sarmaticus, two taxa which were also found in the Coprolitic Horizon. The described fossil material of pipehorses indicates that seahorses evolved from a group of pipehorses that were similar in size and shape to extant and fossil pipehorses of the Haliichthyinae subfamily.  相似文献   

18.
Phalacrocorax owrei nov. sp. is a small cormorant from the Lower Pleistocene of Olduvai Gorge. Osteological proportions are established for the four subgenera of Phalacrocorax, and P. owrei is assigned to the subgenus Stictocarbo. The species was the most abundant bird in the Bed I deposits and is also represented by a few specimens in the middle part of Bed II. Its last known appearance coincides with a change in the local environment when the climate became more arid and the Olduvai Lake became more saline and more alkaline. At other localities in Bed II the extinct P. tanzanice occurs, as well as P. africanus and P. corbo, which breed on the African lakes and seacoast today.  相似文献   

19.
《Comptes Rendus Palevol》2018,17(6):351-356
Fossils belonging to Ripidiinae are rare. Here, we describe and figure a remarkable new genus and species of Ripidiinae, Protoripidius burmiticus gen. et sp. nov., from the Upper Cretaceous amber of Myanmar. Protoripidius can be placed in the extant subfamily Ripidiinae based on the widely separated and abbreviated elytra (in male), unfolded hind wings, simple claws and the absence of tibial spurs. Protoripidius bears many transitional features shedding new light on the relationships of the two extant tribes of Ripidiinae. The discovery also highlights the palaeodiversity of the subfamily Ripidiinae in the mid-Cretaceous.  相似文献   

20.
ABSTRACT

A new fossil species of the genus Scutus (Scutus mirus n. sp.) is described from five Late Oligocene to Early Miocene (Waitakian to Altonian; 25.2–15.9?Ma) localities in the South Island, New Zealand. It is one of the oldest fossil species of Scutus known and probably inhabited very shallow, sub-tropical waters surrounding Zealandia during this time. The holotype of Scutus petrafixus Finlay, 1930 is re-examined; it is possibly from All Day Bay, Kakanui (Waitakian 25.2–21.7?Ma). The New Zealand species documented herein significantly expand our understanding of the fossil record of this shallow-marine molluscan lineage, and by proxy, also indicate the presence of very shallow coastal marine environments around the late Oligocene and early Miocene in southern Zealandia.  相似文献   

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