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1.
This paper deals with the taxonomic revision of the Early Cretaceous large, many-chambered planispiral planktonic foraminifera, historically assigned to the genus Globigerinelloides or alternatively assigned in the 1990s to the genera Globigerinelloides Cushman and ten Dam, Biglobigerinella Lalicker, Blowiella Krechmar and Gorbachik and Alanlordella BouDagher-Fadel. In a previous paper we demonstrated that the morphological and microstructural features used in the literature for distinguishing Blowiella from Globigerinelloides have value only at species level, and the former genus was thus invalidated (being the junior synonym). Moreover, the Late Aptian specimens assigned to Biglobigerinella by some authors, based on the presence of twin last chamber(s), are also included in Globigerinelloides because individuals sharing the same features (number of chambers, growth rate, size of umbilicus, and a finely perforate wall) may or may not possess twin last chamber(s). Meanwhile, Moullade et al. questioned the taxonomic value of Alanlordella, erected by BouDagher-Fadel to accommodate planispiral taxa possessing a macroperforate wall. All the species analysed here possess a finely perforate wall and consequently cannot be assigned to this taxon.The large species of Globigerinelloides retained here, with six or more chambers in the outer whorl, are G. algerianus Cushman and ten Dam, G. aptiensis Longoria, G. barri (Bolli, Loeblich and Tappan) and G. ferreolensis (Moullade).In the sections studied, Globigerinelloides aptiensis was first found close to the Barremian/Aptian boundary, even though this species was recorded in Spain (Rio Argos) in the mid Upper Barremian; very rare, small, seven-chambered individuals here assigned to Globigerinelloides ferreolensis are recorded in the Lower Aptian (just below and within the Selli Level, OAE1a), while a few specimens belonging to Globigerinelloides barri occur in the Globigerinelloides ferreolensis Zone (Upper Aptian). Globigerinelloides aptiensis and G. ferreolensis range up to the Ticinella bejaouaensis Zone while Globigerinelloides barri disappears at the top of the Globigerinelloides algerianus Zone; finally, Globigerinelloides algerianus obviously spans the eponymous total range zone.From an evolutionary point of view, two lineages within the many-chambered Globigerinelloides have been recognized. In the first, already known in the literature, Globigerinelloides aptiensis gave rise to G. ferreolensis, which evolved into G. algerianus; the latter in turn gave rise to Pseudoplanomalina cheniourensis as the final evolutionary member. In the second lineage Globigerinelloides barri originated from G. blowi. 相似文献
2.
An analysis of lower Barremian invertebrate trace fossils at the El Hoyo dinosaur tracksite (Teruel, Spain) was conducted in order to interpret the macrobenthic tracemaker community and the palaeoenvironmental conditions during bioturbation. Abundant bioturbation structures are characterized by meniscate, cylindrical, straight to sinuous, unbranched epichnia, showing the absence of lining, mantle and longitudinal striations. These structures are included in the ichnogenus Taenidium. Burrow width, distance between menisci, type of their fill, and general shape, allow for identification of the ichnospecies Taenidium serpentinum and T. barretti. Dominance to near exclusiveness of Taenidium in the invertebrate trace fossil assemblage suggests assignation to the Scoyenia ichnofacies. This agrees with the presence of vertebrate tracks. Accordingly, a transitional zone between terrestrial and nonmarine aquatic environments, i.e., floodplain areas adjacent to rivers and affected by low energy conditions, could correspond to the El Hoyo site. The pervasive ichnofabric of Taenidium reveals an opportunistic behaviour of the tracemaker, bioturbating rapidly after deposition; bioturbation took place in moist to wet substrates—softgrounds—in shallow tiers, during favourable yet episodic conditions. The opportunistic strategy might owe to a rapid accumulation of nutrients buried within the sediment during alluvial discharges. After bioturbation, minor erosions during fluvial discharges or subaerial exposure may have caused differences in the preservation of the Taenidium. 相似文献
3.
Recently discovered dinosaur bones in submerged near-shore deposits of southwest Istria include one vertebra, one femur, and two rib fragments. They all show well-developed vascularization. The large amounts of primary bone tissue in the vertebral and femoral compacta as well as in one rib fragment suggest that they belong to sub-adult animals which were growing rapidly. The structure of a second rib fragment differs in that it consists of secondary bone. The absence of lines of arrested growth is evident in all investigated bones. This suggests a sustained manner of bone deposition. 相似文献
4.
N. -A. Mrner 《Cretaceous Research》1980,1(4):329-340
A priori, the recorded relative sea-level changes during the Cretaceous must be the combined effect of tectono-eustasy, geoidal-eustasy and various crustal level changes. To this we must add the human factor of differences and errors in interpretations.A posteriori, it is claimed that geoidal-eustasy dominated during the Hauterivian, Barremian, Turonian, Santonian and Maastrichtian, that tectono-eustasy dominated during the Albian, Cenomanian, Campanian and at the Maastrichtian/Danian boundary, and that local influences of sea-floor spreading are identified from the Albian/Cenomanian boundary onwards. To this we must add the local differential crustal movements modulating the global and regional ocean level changes. Geoidal-eustasy is mainly expressed as a latitudinal differentiation of the sea-level with out-of-phase changes between the hemispheres or the both high latitude regions. Furthermore, sedimentological records seem to record short-period geoidal-eustatic cycles. 相似文献
5.
Late Barremian ammonite fauna from the epipelagic marlstone and marly limestone interbeds of Boljetin Hill (Boljetinsko Brdo) of Danubic Unit (eastern Serbia) is described. The ammonite fauna includes representatives of three suborders (Phylloceratina, Lytoceratina and Ancyloceratina), specifically Hypophylloceras danubiense n. sp., Lepeniceras lepense Rabrenović, Holcophylloceras avrami n. sp., Phyllopachyceras baborense (Coquand), Phyllopachyceras petkovici n. sp., Phyllopachyceras eichwaldi eichwaldi (Karakash), Phyllopachyceras ectocostatum Drushchits, Protetragonites crebrisulcatus (Uhlig), Macroscaphites perforatus Avram, Acantholytoceras cf. subcirculare (Avram), Dissimilites cf. trinodosus (d'Orbigny) and Argvethites? sp. The taxonomic composition and percent abundance of the identified ammonites indicate that their taxa are predominantly confined to the Tethyan realm. Ammonites with smooth and slightly sculptured shells predominate among the studied fauna. The ammonite-bearing succession from Boljetin represents the lower part of the Upper Barremian, ranging in ammonite zonation from the Toxancyloceras vandenheckei Zone to the lower part of the Imerites giraudi Zone. The associated organic-walled dinoflagellate cysts confirm the Late Barremian age of the ammonite-bearing levels. 相似文献
6.
《Proceedings of the Geologists' Association. Geologists' Association》2017,128(2):256-270
Three new Lower Cretaceous vertebrate sites (Vadillos-1, Vadillos-2, El Tobar) have been recently discovered and studied in the Cuenca Province (Central Spain). They are located in deposits of “Wealden” facies belonging to the El Collado Sandstone and Clay Formation. In these outcrops, micro and macroremains corresponding to plants, invertebrates and vertebrates have been collected and subsequently assigned to macrophytes, charophytes (e.g., Atopochara trivolvis triquetra, Globator maillardii trochiliscoides, Clavator harrisii harrisii), ostracods (e.g., Cypridea gr. modesta, Cypridea cf. C. isasae, Cypridea sp. aff. C. moneta, Cypridea sp. 1, Cypridea sp. 2), molluscs (Unionoida, Viviparus sp.), fishes, amphibians, turtles (cf. Eucryptodira), crocodyliforms (Neosuchia) and dinosaurs (ankylosaurs, ornithopods, theropods). Among the vertebrate remains, scales, teeth, plates, osteoderms, phalanges, ribs, vertebrae and other incomplete bones, as well as eggshell fragments have been identified. This rich and diverse assemblage was deposited in an upper Barremian alluvial-palustrine muddy floodplain crossed by braided sandy channels. 相似文献
7.
Orbitolinid foraminifers are reported for the first time from lower Barremian shallow marine carbonate deposits of the Moghan area, NW Iran. According to geologic map of the Razi, these rocks were previously assigned to general age of the Early Cretaceous. The early Barremian age is documented based on stratigraphic range of the marker Valserina turbinata (Foury). Other orbitolinids such as Eopalorbitolina charollaisi Schroeder, Eopalorbitolina pertenuis (Foury), Paleodictyoconus cf. cuvillieri (Foury), Montseciella cf. alguerensis Cherchi and Schroeder, Paracoskinolina cf. maynci (Chevalier), Orbitolinopsis cf. buccifer Arnaud-Vanneau and Thieuloy, and Dictyoconus? pachymarginalis Schroeder also coexist. Obtained biostratigraphic data suggest that the range of Dictyoconus? pachymarginalis, hitherto known from the Aptian, has to be extended into the early Barremian. Most of the orbitolinid taxa are well known in Europe as northern Tethyan margin endemic forms. Therefore, the study area can be considered as part of the northern Tethys margin during the Barremian. This study also extends the palaeobiogeographic distribution of northern Tethyan orbitolinids eastwards as far as northwest Iran. 相似文献
8.
Impact of dynamic sedimentation on facies heterogeneities in Lower Cretaceous peritidal deposits of central east Oman 总被引：1，自引：0，他引：1
This study, based in the Haushi‐Huqf area of central east Oman, aims to characterize the controls on facies distribution and geometries of some of the best preserved examples of Lower Cretaceous tidal flat facies within the Tethyan epeiric platform. Field, petrographic and geochemical data were acquired from the Barremian–Aptian Jurf and Qishn formations that crop out in a 500 × 1000 m2 butte, thus allowing for pseudo three‐dimensional quantitative data acquisition of the dimensions and spatial distributions of discontinuity surfaces and sedimentary bodies. The interpretation presented here suggests that the main processes impacting sedimentation in the Lower Cretaceous peritidal environment of the Haushi‐Huqf were transport and erosion processes related to storm waves and currents. The vertical evolution of the carbonate system is organized into six types of metre‐scale depositional sequences, from subtidal dominated sequences to supratidal‐capped sequences, which are bounded by regional discontinuity surfaces. At subaerial exposure and submarine erosion surfaces associated with a base level shift, sedimentary horizons along the entire depositional profile are cut by scours possibly created by storm events. Chemostratigraphy allows correlation between the Haushi‐Huqf and the age‐equivalent sections logged in the interior of the platform in Oman. The correlation suggests that the change from subtidal to intertidal depositional sequences during the late highstand is coeval with the development of rudist dominated shoals on the shelf. This study is the first to discuss the controls on Lower Cretaceous peritidal carbonate cyclicity of the Arabian epeiric platform. The results presented here also offer a unique quantitative dataset of the distribution and dimensions of peritidal carbonate shoals and storm scours in a regional sequence stratigraphic context. 相似文献
9.
The larger benthic foraminifer Torremiroella hispanica Brun and Canérot, 1979, so far only known from its type-locality in southern Spain, is described from the Late Barremian–Early Aptian of Central Iran (Ardakan and Yazd areas). It is reported from foraminiferan pack- to grainstones associated with Balkhania balkhanica Mamontova, 1966, dated as early Aptian (Bedoulian). A review of the literature data suggests that both are typical northern Tethyan faunal components as indicated also by the assemblages of orbitolinid foraminifers and dasycladalean algae. 相似文献
10.
Seven specimens of fossil scorpionflies (Mecoptera) not assignable to any known family were discovered in the Wealden Supergroup (Lower Cretaceous) of southern England. They were found at Rudgwick Brickworks, West Sussex and Smokejacks Brickworks, Surrey and came from the Upper Weald Clay Formation, dated as Barremian (∼129.4–125 Ma). A new family – Englathaumatidae fam. nov., new genus – Englathauma gen. nov. and two new species E. crabbi sp. nov. and E. mellishae sp. nov. are described. A discussion of systematic position of these new taxa within the order Mecoptera is given. Englathaumatidae fam. nov. has been a nomen nudum since the year 2002, due to the first author's untimely death. 相似文献