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1.
Nummulites bahariyaensisn. sp., typical of Nummulites partschi group, Nummulites gizehensis subgroup, is biometrically studied, described and photographed through both generations from El-Hamra Formation, Garra El Hamra, northern plateau of Bahariya Oasis, Western Desert of Egypt. From the biometric analysis, N. bahariyaensis is phylogenetically parallel to Nummulites lyelli, both of Bartonian age based on the presence of Nummulites decrouezae and Nummulites aff. pulchellus which were dated as Bartonian from Gebel Mokattam, the species which is equated with those from Naalon stratigraphic section, Fayum, by Morsi et al. (2003). Nummulites bahariyaensis could be compared with Nummulites champollioni as both are thick in the microspheric generation. However, the phylogeny of the present new species should be searched on. The described species spans SBZ 17 of the Shallow Benthic Zones of Serra-Kiel et al. (1998, Bull Soc Geol France 169(2):281–299), which denotes an Early Bartonian ( = Biarritzian sensu Hottinger and Schaub 1960, Eclogae Geol Helv 53: 453–479). At Garra El Hamra, El-Hamra Formation with N. bahariyaensis unconformably overlies the Qazzun Formation (Late Ypresian) emphasising that the Lutetian and the top part of Ypresian possibly are missing.http://zoobank.org/22549148-0BD6-4097-A22C-01CA614B5CE1  相似文献   

2.
One hundred and seventy collected samples from Jebil section have been carefully studied for their ostracod content and referred to 41 species belonging to 20 genera. Their vertical distribution allowed to distinguish five successive associations of ostracod assemblages; two of which are correlated with the Early Lutetian, one with the Late Lutetian, another association with the Bartonian and the last one with the Priabonian. Community structure of the collected ostracod fauna has been studied; three indices have been calculated for each sample: Shannon (diversity), Margalef (richness) and Equitability indexes. In the lower and the middle part of the Formation, they indicate a stable environment supporting high diversity ostracod communities; whereas in the upper portion the environmental conditions were unstable characterized by low diversity. The results of a multivariate statistical method, using the cluster analysis and the Detrended Correspondence Analysis of the 41 ostracod species and the 170 samples, have led to conclude that the most effective environmental factor in the study area is the paleodepth and of less importance oxygenation and salinity. Thus, it allowed to distinguish four palaeoenvironmental intervals within the Cherahil Formation: the first one represented by taxa that are known from the shallower parts of the shelf; the second interval includes the majority of the encountered species of inner neritic shelf with normal salinity; the third one, corresponding to an outer neritic domain; and the last interval refers to a circalittoral environment, is comprised mainly of Cytherella angulata and of Soudanella laciniosa triangulata.  相似文献   

3.
Nummulites beaumonti d'Archiac & Haime, 1853, originally described from El Basatin, Gebel Mokattam, Greater Cairo, is redefined from a nummulitic bank at the base of the Maadi Formation from its type locality as neotype. Schaub (1981) described the species from Libya and the type example of this species is still unknown. N. discorbinus Schlotheim (1820) is described as neotype from a nummulitic bank in the Mokattam Formation, which is located in the site of the Citadel tombs, near the Salah El Din Citadel, Gebel Mokattam, Egypt. According to Schaub (1981), the type example of this species is also unknown. For this reason the establishment of the neotypes of these two widespread nummulites species: N. discorbinus (Late Lutetian) and N. beaumonti (Bartonian) is important and tackled in this paper. N. qurnensis n. sp. ( = N. sp. cf. beaumonti in Boukhary et al. 2002) is introduced as a new species from the lower Bartonian part of the Qurn Formation of Helwan. Biometrical studies are carried out on the three species to present up to date information on these Nummulites, with particular attention to their biostratigraphic correlation with the Shallow Benthic Zones (SBZ) of Serra-Kiel et al. 1998. The authors would like to stress the importance of a careful designation of a neotype to avoid the introduction of complicated and unnecessary taxonomic problems.  相似文献   

4.
Nummulites paucispira and Nummulites kaitbeyi are newly erected from the Upper Building Stone Member (Bartonian) of the Mokattam Formation at Kait Bey, Gebel Mokattam, Greater Cairo, Egypt both belong to Nummulites partschi group. N. paucispira and N. kaitbeyi are different in their ontogenetic growth stages; N. paucispira has a step of coiling from tight to lax, contrary to N. kaitbeyi. The regression line of both species indicates that both are distinct and they belong to different lineages. Detailed investigations of the new species N. paucispira n. sp. and N. kaitbeyi n. sp. of N. partschi group and their ontogenetic growth stages are discussed. This study is of considerable importance for distinguishing paleoecological events of Bartonian stage and for tracing the phylogenetic trends for the entire Tethys basin.  相似文献   

5.
Two new species of Nummulites and one subspecies of Orbitoclypeus from the Eocene of the Crimean Mountains and Mangyshlak Peninsula are described in detail. Nummulites alexisi sp. nov. and Orbitoclypeus munieri major subsp. nov. come from the Upper Ypresian, while Nummulites ninikae sp. nov. is from the Lower-Middle Lutetian. The phylogenetic position of new taxa is discussed.  相似文献   

6.
The marine middle Burdigalian sediments of the North Alpine Foreland Basin (NAFB) or Molasse Basin are well known for abundant occurrences of benthic foraminifers and ostracods. However, taxonomic studies of ostracod assemblages are comparatively rare and, given its abundance, the group remains heavily understudied. Here we report a new, rich and well-preserved ostracod fauna from the middle Burdigalian Neuhofen Formation at Mitterdorf, in the northeastern part of the NAFB. The material comprises a total of 3029 ostracod specimens. We identified 44 species; all species are described and, with one exception, illustrated. Our material reveals the presence of 17 ostracod species that were previously unknown from the middle Burdigalian in the NAFB, i.e., Cytherella aff. vulgatella, Cytherella aff. méhesi, Bairdoppilata aff. subdeltoidea, Paranesidea? sp., Paracypris aff. aerodynamica, Parakrithe dactylomorpha, Pseudopsammocythere sp., Callistocythere daedalea, Costa aff. reticulata, Ruggieria aff. longecarenata, Heliocythere aff. vejhonensis, Heliocythere sp., Loxocorniculum hastatum, Neocytherideis cypria, Cytheretta cf. tenuipunctata dentata, Cytheropteron cf. ruggierii, and Semicytherura resecta. The palaeobiogeography of the ostracods indicates a relatively open marine Burdigalian connection between the NAFB and the Mediterranean Sea, in agreement with previous work. Our data also suggest that a significant degree of endemism existed in the middle Burdigalian sea of the NAFB, of which previous studies yielded only sparse signs. Moreover, our results indicate that some ostracod species survived the late Burdigalian sea retreat from the NAFB by dispersing eastward into the adjacent regions (Vienna Basin, Carpathian Foredeep), where marine conditions still prevailed. A compilation of all known middle Burdigalian ostracod faunas from the NAFB documents a high species diversity, with over 120 species. Their spatial distribution, with many species being restricted to a single site, suggests heterogenous microhabitats, possibly influenced by small-scale differences in water depth, nutrient availability and oxygenation.  相似文献   

7.
The ostracod fauna collected from the Cherahil formation that crops out at the Jebel Serj section (central Tunisia) contains 24 species belonging to 12 genera. These ostracods are associated with 9 genera of benthic Foraminifera (including 4 Nummulites species) and 7 genera of planktonic Foraminifera. The biostratigraphic study of ostracod assemblages results to the recognition of 6 biozones which are correlated with Lutetian-Priabonian. The Shannon Weaver, Margalef and equitability indices point to internal platform netritic conditions, with minor fluctuations in depth and oxygenation. The palaeobiogeographic distribution of ostracod species found in the study area of Central of Tunisia establishes a good connexion with the basins developed in Northern Africa (Tunisia, Algeria, Libya and Mauritania) and the Middle East (Egypt and Jordan).  相似文献   

8.
9.
Dr. Davide Bassi 《Facies》1998,39(1):179-201
Summary The Calcare di Nago is a carbonate unit of Middle-Late Eocene (Bartonian and Priabonian) age which is well exposed at the north-eastern end of Lake Garda, on the western margin of the Lessini Shelf (Southern Alps). This unit is highly fossiliferous as far as the coralline red algae and large foraminifera are concerned. Corals, bryozoans, echinoderms, and molluscs are also present. The present study deals with the relationships among the coralline taxa, the coralline growth-forms, and their facies development in the Priabonian part of the type section of the Calcare di Nago. The taxonomic investigation led to the identification of 15 coralline red algal species belonging to 7 non-geniculate and 2 geniculate genera. One species of Peyssonneliacean (red alga) and one of Halimedacean (green alga) were also recognized. The quantitative and qualitative analyses based on coralline red algae and large foraminifera enabled five facies to be distinguished: Algal crust-branch rudstone, Algal/Discocyclina packstone, Coralalgal boundstone, Rhodolith mound wacke/packstone, and Rhodolith pavement. According to the coralline assemblages, coralline growth-forms, and large foraminiferal associations, the five facies reflect solid and soft substrate types. Some of these facies are dominated byin situ rhodoliths, others by reworked algal debris. In the architecture of an interpreted prograding carbonate ramp, shallow water facies are dominated by members of the subfamily Mastophoroideae, while deeper water facies are dominated by those of the subfamily Melobesioideae and family Sporolithaceae. There is a significant increase both in size and in constructional voids of the rhodoliths with depth. A concomitant decrease in algal species diversity with depth has been also recognized. LargeDiscocyclina assemblages are localized across the inner and mid ramp boundary.Pellatispira andBiplanispira are present only in the uppermost mid-ramp.Nummulites, Assilina, andSpiroclypeus are dominant together with small orthophragminids both in the mid- and uppermost outer ramp facies.  相似文献   

10.
Two new species of carcharhinid sharks from the Late Eocene deposits (Tavda Formation) of the southern Trans-Urals, Abdounia vassilyevae sp. nov., previously determined as A. aff. beaugei, and A. lata sp. nov., are described. To date, up to five Priabonian species of Abdounia have been recorded. New finds supplement the data on diversity, evolution, and paleobiogeography of Abdounia.  相似文献   

11.
《Comptes Rendus Palevol》2014,13(7):599-610
The Samlat Formation is well exposed in coastal sections bordering the Atlantic Ocean south of Ad-Dakhla in southwestern Morocco. Here some 22 m of rhythmically-bedded, chert-rich, marine siltstones and marls are overlain by 1–1.5 m of vertebrate-bearing microconglomeratic sandstone, another 4–8 m of rhythmically-bedded siltstone and marl, and finally a second 3–6 m unit of vertebrate-bearing muddy sandstone. The microconglomeratic and muddy sandstones represent low sea stands in what is otherwise a deeper water sequence. Cetacean skeletons are rare but cetacean vertebrae are common in the lower sandstone (bed B1), where many show the effects of reworking. The cetaceans in bed B1represent a minimum of five species, from smallest to largest: cf. Saghacetus sp., cf. Stromerius sp., Dorudon atrox, cf. Dorudon sp., and Basilosaurus isis. Bed B1 yields rib fragments that may represent sirenians, but sirenians, if present, are rare. The only identifiable cetacean found in the upper sandstone (bed B2) is Basilosaurus sp. Dugongid sirenians identified as cf. Eosiren sp. are the most common mammal in bed B2. We interpret co-occurrence of the typically Early Priabonian species Dorudon atrox and Basilosaurus isis with smaller species more like Middle Priabonian genera Saghacetus osiris and Stromerius nidensis to indicate that bed B1 was deposited during low sea stand Pr-2 between the Early and Middle Priabonian (between the early and middle Late Eocene). Bed B2 is separated from B1 by an interval of deeper water sediment accumulation. Bed B2 could represent a later phase of Pr-2 or a subsequent Priabonian low sea stand (possibly Pr-3).  相似文献   

12.
We describe a new large-sized species of hypercarnivorous hyainailourine–Kerberos langebadreae gen. & sp. nov.–from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae shows that large body size appears early in the evolution of hyainailourines. Surprisingly, the late Miocene Hyainailouros shares a more recent common ancestor with small-bodied hyainailourines (below 15 kg). Finally, our study supports a close relationship between the Hyainailourinae and Apterodontinae and we propose the new clade: Hyainailouridae.  相似文献   

13.
Larger benthic foraminifera (LBF) are significant proxies in biostratigraphy and also act as excellent indicators of shallow-marine carbonate environments in fossil series. The Palaeogene LBF recorded from Meghalaya, NE India (eastern part of the relic eastern Tethys/Neo-Tethys) have high potential for dating shallow-marine sediments and documenting the multiple episodes of carbonate sedimentation that have contributed to the development of the Sylhet Limestone Group. Early Eocene witnessed the proliferation of LBF species worldwide, the phenomenon better known as the Larger Foraminiferal Turnover (LFT). Genera like Alveolina, Nummulites and Orbitolites with broad species complexes thrived as the dominant LBF amidst numerous other taxa on the verge of extinction or only surviving as stable forms. The current study emphasizes on the biostratigraphic and palaeoenvironmental account of the early Eocene Umlatdoh Limestone successions outcropping in the Jaintia Hills of Meghalaya, primarily based on the recorded species of Alveolina and other larger benthic foraminifera. Five species of AlveolinaA. oblonga, A. schwageri, A. cf. ruetimeyeri, A. aff. haymanensis and A. aff. varians are recorded in the evaluated sections that indicate an early Eocene age corresponding to the Shallow Benthic Zone 10. Major carbonate facies types in the present assessment include oolitic-smaller benthic foraminiferal -green algal grainstone–packstone, smaller miliolid-Alveolina grainstone, green algal-benthic foraminiferal grainstone, larger porcellaneous (Alveolina) grainstone-packstone, Alveolina-nummulitid grainstone-rudstone, and nummulitid grainstone-rudstone, which indicate a shallow marine, high-energy depositional environment ranging from shoal-sandy bars to a distal inner ramp setting.  相似文献   

14.
The Middle Eocene Climatic Optimum (MECO) at ~40 Ma is a significant global warming event associated with pronounced changes in the hydrosphere, atmosphere, and biosphere. The Kohat Formation in the Kohat Basin (eastern Tethys, Pakistan) is studied for identifying the response of larger benthic foraminifera (LBF) to MECO. The LBF assemblages in the Kohat Formation, covering from the Shallow Benthic Zones (SBZ) 15 to 17, suggest middle Lutetian to early Bartonian in age. Microfacies analyses indicate a lagoonal (inner carbonate ramp facies belt) to open marine (middle carbonate ramp facies belt) paleodepositional environment of the Kohat Formation. A distinct positive δ13C shift marks the stratigraphic position of the MECO in this formation. At the Peak-MECO event that is marked by the onset of the positive carbon isotope excursion (CIE), no evident compositional variation in the LBF assemblages is observed. However, significant changes in the LBF assemblages with the local first and last occurrences of some LBF genera can be observed in the Post-MECO and CIE recovery phase. These changes are verified by the sudden disappearance of Alveolina and orthophragminids and initial dominance of larger shell-size Nummulites fabianii, Heterostegina, and Linderina species accompanied by an increase in the species diversity. Here, we argue that the change in the observed LBF assemblages in the uppermost part of the Kohat Formation might be related to a larger foraminiferal turnover occurring during the Post-MECO event and corresponds to the CIE recovery phase.  相似文献   

15.
This paper presents the first Permian ostracod fauna discovered in Thailand. The ostracods are recovered from the Tak Fa Limestone (Middle Permian) in Phetchabun province, central Thailand. The ostracods belong to eight genera and 15 species. Four species are newly described: Sargentina phetchabunensis nov. sp., Geffenina bungsamphanensis nov. sp., Reviya subsompongensis nov. sp. and Bairdia takfaensis nov. sp. The ostracod assemblages characterize a shallow marine, near shore environment at the time of deposition. Except for one species, which shows palaeobiogeographical links between Central Thailand and South China, all the other species are endemic.  相似文献   

16.
The distribution of ostracod valves was studied in seven short (< 50 cm) sediment cores collected from the sublittoral-profundal zones (depth > 12 m) of four lowland, dimictic lakes (Kamedu?, Szelment Ma?y, Szelment Wielki and Szurpi?y) situated in the Eastern Suwa?ki Lakeland of NE Poland. These postglacial channel lakes are still moderate in trophy level, but to some extent, they differ from each other in the increase of anthropogenic alterations, especially in their hypolimnion. The studied sediment sequences, corresponding roughly to the period of the last ca. 300 years, yielded ca. 5500 valves of 20 ostracod species, out of which only seven are here considered as the autochthonous profundal component of the fossil assemblages: Candona candida, C. neglecta, Fabaeformiscandona protzi, F. tricicatricosa, Bentocypria curvifurcata, Cytherissa lacustris and Limnocytherina sanctipatricii. Valves of the remaining species were most probably subjected to postmortem transport from shallow water deposits or from lakeside and/or subaqueous springs, and thus were not deposited in situ at the deep bottom. By clustering classification and multi-dimensional scaling ordination, three major assemblage types were recognised in the moderately eutrophicated parts of the studied lakes: (a) assemblage dominated by C. candida, (b) assemblage dominated by C. lacustris and (c) the most diverse assemblage, in which four species (C. lacustris, C. candida, F. protzi and C. neglecta) occur in more or less equal percentages. On the other hand, sediments of the most eutrophic basins of the lakes (especially in Kamedu? and Szelment Ma?y) are characterised by the decline of total valve abundances and complete extinction of C. lacustris, a species indicative of low trophy, so that, in extreme cases, a few valves (if any) of more eurytopic or only allochthonous species could be found in some of the uppermost layers. Successional transitions of the recognised assemblage types are discussed according to the generalised model of the deep lacustrine ostracod succession previously established for the Polish lakes on the country scale. The recorded assemblages correspond well with the trophic diversity of the studied lakes, confirming inferences based on previously published data on other trophy indices from this area. Finally, additional data on modern profundal ostracod fauna from dredge samples of the studied lakes are also provided.  相似文献   

17.
18.
《Comptes Rendus Palevol》2003,2(5):317-324
Application of the fuzzy set theory to the biometric evaluation of the species Nummulites millecaput in the western part of the Tethys. The goal of this paper is to demonstrate the ability of the fuzzy-set theory to contribute to the evaluation of paleontological problems. As an example, the species Nummulites millecaput, Boubée has been chosen. One hundred specimens of this species, collected from four localities (Arrimblar, Adelholzen, Dudar, and Mount-Kotuc) have been prepared (equatorial sections) for the biometric measurement of the external and internal characteristics. First a traditional statistical evaluation was performed, followed by the construction of membership functions, the latter ones expressing in the best way the transitions from one locality to the other. The results of this evaluation confirmed that from Aquitaine (France) to Armenia, the same species – Nummulites millecaput – was distributed during the Eocene. To cite this article: G. Bárdossy et al., C. R. Palevol 2 (2003).  相似文献   

19.
A Middle–Late Eocene diagnostic larger foraminiferal assemblage is described and illustrated from carbonates of the uppermost Dammam Formation, on both sides of Gebel Hafit anticline in the Northern Oman Mountains in the United Arab Emirates. The Middle Eocene carbonates yielded Nummulites obesus d'Archiac, 1852, N. ismaili Boukhary, Hamdan & Bahr n. sp., N. papazzonii Boukhary, Hamdan & Bahr n. sp. and N. kenawyi Boukhary, Hamdan & Bahr n. sp. (a species of the N. burdigalensis group). In addition, N. cf. boussaci Rozlozsnik, 1924, N. cf. lorioli De La Harpe, 1879, N. hottingeri Schaub, 1981, N. strougoi Boukhary, Hamdan & Bahr n. sp. (of the N. partschi group), N. ansaryi Boukhary, Hamdan & Bahr n. sp. (of the N. gizehensis group), N. cf. praebullatus Schaub, 1981, N. cizancourti Sander, 1962 (of the group of N. fabianii), N. cf. stamineus Nuttall, 1927 (of the N. discorbinus group), N. maculatus Nuttall, 1926 (of the N. laevigatus group) and Assilina gigantea De La Harpe, 1926 are recorded. On the top of the sequence, an assemblage with N. hottingeri Schaub, 1981, which was assigned by Schaub 1981 to the Biarritzian ( = Bartonian), was found associated with N. ptukhiani, Silvestriella tetraedra (Gümbel, 1870) and Pellatispira madaraszi (Hantken, 1875); these findings suggest that this association should be assigned to the Priabonian stage, confirming for the sampled succession of a Late Eocene age for sediments deposited in an inner-shelf environment, which was possibly related to the eustatic fall of sea level at the end of the Priabonian.

http://zoobank.org/2EBD2891-293F-465A-AE1C-F419F0CDB970  相似文献   

20.
About 200 micromammal isolated teeth (rodents, lagomorphs) originating from the middle Orleanian locality of Béon 2 (Montréal-du-Gers, SW France) are described. The rodent fauna is dominated by myomorphs (7 species), including the cricetid Democricetodon aff. hispanicus Fahlbusch, the melissiodontid Melissiodon sp., the glirids Peridyromys murinus (Pomel), Pseudodryomys aff. ibericus, Pseudodryomys aff. simplicidens, and Glirudinus modestus (Dehm), and the eomyid Ligerimys aff. florancei. Sciuromorphs are represented only by Heteroxerus rubricati Crusafont, Villalta and Truyols. Within lagomorphs, 2 dental morphs referred to the ochotonid Prolagus Pomel are identified in Béon 2. They correspond to Prolagus oeningensis (König) and P. aff. vasconiensis. On a biostratigraphical point of view, this study confirms the location of Béon 2 at the early part of the MN4; this locality is older than other regional sites such as Pellecahus, Béon 1, La Romieu, and Bézian (MN4b), and it is coeval to Artenay, in the Loire basin. In particular, glirids and lagomorphs from Béon 2 testify to close relationships with micromammal localities referred to the MN3 biozone.  相似文献   

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