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Carnets Geol., vol. 20, nº 05

Tue, 17 Mar 2020 12:09:59 GMT

Alberto Collareta, Luz Tejada-Medina, César Chacaltana-Budiel, Walter Landini, Alí Altamirano-Sierra, Mario Urbina-Schmitt & Giovanni Bianucci.- A rhinopristiform sawfish (genus Pristis) from the middle Eocene (Lutetian) of southern Peru and its regional implications.- Modern sawfishes (Rhinopristiformes: Pristidae) are circumglobally distributed in warm waters and are common in proximal marine and even freshwater habitats. The fossil record of modern pristid genera (i.e., Pristis and Anoxypristis) dates back to the early Eocene and is mostly represented by isolated rostral spines and oral teeth, with phosphatised rostra representing exceptional occurrences. Here, we report on a partial pristid rostrum, exhibiting several articulated rostral spines, from middle Eocene strata of the Paracas Formation (Yumaque Member) exposed in the southern Peruvian East Pisco Basin. This finely preserved specimen shows anatomical structures that are unlikely to leave a fossil record, e.g., the paracentral grooves that extend along the ventral surface of the rostrum. Based on the morphology of the rostral spines, this fossil sawfish is here identified as belonging to Pristis. To our knowledge, this discovery represents the geologically oldest known occurrence of Pristidae from the Pacific Coast of South America. Although the fossil record of pristids from the East Pisco Basin spans from the middle Eocene to the late Miocene, sawfishes are no longer present in the modern cool, upwelling-influenced coastal waters of southern Peru. Given the ecological preferences of the extant members of Pristis, the occurrence of this genus in the Paracas deposits suggests that middle Eocene nearshore waters in southern Peru were warmer than today. The eventual disappearance of pristids from the coastal waters off southern Peru might be interpreted as reflecting the late Cenozoic trend of strengthening of the Humboldt Current.- Handle-ID: http://hdl.handle.net/2042/70759

 

Carnets Geol., vol. 20, nº 04

Sat, 22 Feb 2020 12:04:40 GMT

Francis Amédro, Francis Robaszynski, Hervé Châtelier, Patrice Ferchaud & Bertrand Matrion.- Identification d'un biohorizon d'ammonites à Romaniceras (Romaniceras) marigniacum sp. nov. (Turonien moyen) à la base du Tuffeau Jaune de Touraine (France). Identification of a Romaniceras (Romaniceras) marigniacum sp. nov. ammonite biohorizon (Middle Turonian) at the base of the Tuffeau Jaune de Touraine (France).- Dans le sud du Bassin de Paris, le long des vallées de la Loire et du Cher, le Tuffeau Jaune de Touraine a été traditionnellement daté du Turonien supérieur par la présence de très rares Romaniceras deverianum (Orbigny, 1841). Toutefois, les quelques mètres de tempestites à la base de la formation n'ont jamais livré d'ammonites. Aujourd'hui, juste au sud du Turonien stratotypique, en Touraine méridionale, la récolte de plus de 150 ammonites à la base du Tuffeau Jaune de Touraine ainsi que dans le sommet du Tuffeau de Bourré sous-jacent apporte des précisions significatives sur l'âge des formations. En réalité, les premiers mètres du Tuffeau Jaune de Touraine appartiennent encore à la zone à Romaniceras ornatissimum (Tm 3) datant le Turonien moyen. La découverte dans cet intervalle de Romaniceras (Yubariceras) ornatissimum (Stoliczka, 1864) associé à la nouvelle espèce Romaniceras (R.) marigniacum Amédro & Châtelier sp. nov. indique qu'on se trouve dans la partie élevée de la zone à R. ornatissimum. D'autres espèces sont présentes dans ce biohorizon : outre Romaniceras (R.) marigniacum et Romaniceras (Yubariceras) ornatissimum, on trouve Masiaposites cf. kennedyi Amédro & Devalque, 2014, Collignoniceras woollgari regulare (Haas, 1946), C. turoniense (Sornay, 1951) et Collignoniceras vigennum Amédro & Châtelier sp. nov. Le sommet du Tuffeau de Bourré a quant à lui livré une cinquantaine d'ammonites avec une association légèrement différente de celle connue dans la localité type de Bourré-Montrichard dans la vallée du Cher. Le matériel récolté près de la confluence Vienne-Creuse comprend : Lewesiceras peramplum (Mantell, 1822), Romaniceras (Y.) ornatissimum (Stoliczka, 1864), Collignoniceras woollgari regulare (Haas, 1946), C. canthus (Orbigny, 1856) et C. turoniense (Sornay, 1951). L'espèce Collignoniceras papale (Orbigny, 1841), qui représente un tiers des récoltes à Bourré, est apparemment absente, tandis que trois nouvelles espèces du même genre sont identifiées : C. hourqueigi Amédro & Châtelier sp. nov., C. badilleti Amédro & Châtelier sp. nov. et Collignoniceras sp. A. In the south of the Paris Basin, along the Loire and Cher valleys, the Tuffeau Jaune de Touraine Formation was traditionally attributed to the Late Turonian by the presence of rare Romaniceras deverianum (Orbigny, 1841). Moreover, the several metres of tempestites at the base of the formation never yielded ammonites. Today, in southern Touraine, more than 150 ammonites were collected from the base of the Tuffeau Jaune de Touraine and in the highest part of the underlying Tuffeau de Bourré bring new significant data: the lower part of the Tuffeau Jaune de Touraine remain in the Romaniceras ornatissimum zone, Middle Turonian in age (Tm 3). Furthermore, the discovery in that biohorizon of the new species Romaniceras (R.) marigniacum Amédro & Châtelier sp. nov. is indicative of the highest part of the R. ornatissimum zone (high Tm3). Other species are associated to the R. marigniacum biohorizon as: Romaniceras (Yubariceras) ornatissimum (Stoliczka, 1864), Masiaposites cf. kennedyi Amédro & Devalque, 2014, Collignoniceras woollgari regulare (Haas, 1946), C. turoniense (Sornay, 1951) and Collignoniceras vigennum Amédro & Châtelier sp. nov. With regard to the top of the Tuffeau de Bourré Formation, it yielded about fifty specimens of ammonites but the assemblage is different to that found in the type locality of Bourré-Montrichard in the Cher valley. The material collected near the Vienne and Creuse junction includes : Lewesiceras peramplum (Mantell, 1822), Romaniceras (Y.) ornatissimum (Stoliczka, 1864), Collignoniceras woollgari regulare (Haas, 1946), C. canthus (Orbigny, 1856) and C. turoniense (Sornay, 1951). The species Collignoniceras papale (Orbigny, 1841), which represents one third of the Bourré collection is apparently absent whereas three new species belonging to the same genus are identified as : C. hourqueigi Amédro & Châtelier sp. nov., C. badilleti Amédro & Châtelier sp. nov. and Collignoniceras sp. A.- Handle-ID: http://hdl.handle.net/2042/70720

 

Carnets Geol., vol. 20, nº 03

Sat, 22 Feb 2020 11:59:42 GMT

Cynthia L. de C. Manso.- A new Cassiduloid (Echinodermata, Echinoidea) in the Albian of the Sergipe-Alagoas basin, Brazil.- This paper presents a new discovery of the echinoid species Phyllobrissus humilis (Gauthier, 1875) from the Albian age Riachuelo Formation of the Sergipe-Alagoas Basin. The only specimen obtained in the Maruim 1 outcrop expresses the main species characteristics. Paleoecological notes and a dichotomous key are presented to facilitate the identification of the cassiduloid species from the Cretaceous of Sergipe-Alagoas Basin.- Handle-ID: http://hdl.handle.net/2042/70719

 

Carnets Geol., vol. 20, nº 02

Sat, 22 Feb 2020 11:41:09 GMT

Alberto Collareta, Andrea Di Cencio, Renato Ricci & Giovanni Bianucci.- The shark-toothed dolphin Squalodon (Cetacea: Odontoceti) from the remarkable Montagna della Majella marine vertebrate assemblage (Bolognano Formation, central Italy).- The extinct family Squalodontidae consists of heterodont, medium-sized odontocetes, featuring a long rostrum that houses large, procumbent incisors and heavily ornamented postcanine teeth carrying accessory denticles, hence their vernacular name, "shark-toothed dolphins". These longirostrine toothed whales are often seen as bridging the anatomical gap between archaic Oligocene odontocetes and their late Miocene to Holocene relatives. Possibly among the major marine predators of their time, the shark-toothed dolphins are important components of several lower Miocene marine-mammal assemblages from the North Atlantic and Mediterranean/Paratethysian realms. In the present work, a partial skull of Squalodontidae is described from the strata of the Bolognano Formation cropping out in the northeastern sector of the Montagna della Majella massif (Abruzzo, central Italy), which has previously yielded a rich lower Miocene marine-vertebrate assemblage, including eleven taxa of elasmobranchs as well as subordinate teleosts and very fragmentary remains of marine reptiles and mammals. The specimen consists of the anterodorsal portion of a rostrum, preserving parts of both premaxillae and left maxilla, and the anteriormost seven upper left teeth. This partial skull is here identified as belonging to the genus Squalodon, whose presence in the Montagna della Majella vertebrate assemblage had already been tentatively proposed on the basis of two fragmentary teeth. The paleontological significance of this find is discussed in the broader framework of the Euromediterranean record of Squalodon.- Handle-ID: http://hdl.handle.net/2042/70716

 

Carnets Geol., vol. 20, nº 01

Sat, 22 Feb 2020 11:38:45 GMT

Bruno Granier, Serge Ferry & Mohamed Benzaggagh.- A critical look at Tré Maroua (Le Saix, Hautes-Alpes, France), the Berriasian GSSP candidate section.- The Tré Maroua site in SE France was recently selected by the Berriasian Working Group (BWG) of the International Subcommission on Cretaceous Stratigraphy (ISCS) as the candidate locality for the reference section of the Berriasian Global Boundary Stratotype Point (GSSP). However, on the basis of our preliminary investigation at this site and also from field observations over a larger area, this candidate section is paleogeographically located on a deep-water slope riddled with successive erosional surfaces, stratigraphic hiatuses and breccias. It does not meet at least four of the five "geological requirements for a GSSP". Accordingly, in our opinion, its candidacy must be definitely precluded.- Handle-ID: http://hdl.handle.net/2042/70714

 

Carnets Geol., vol. 19, nº 20

Fri, 27 Dec 2019 11:29:44 GMT

Bruno Granier.- Discussion on some previous records of Involutina hungarica (Sidó, 1952). Revision of the Jesse Harlan Johnson Collection. Part 6.- Involutina hungarica (Sidó, 1952) is reported from Albian strata of Texas (U.S.A.). Earlier records in the scientific literature, where this foraminifer commonly appears under the label "Hensonina lenticularis (Henson, 1947)", are reevaluated. Although it is mostly cited from Albian strata, its first occurrence could be Aptian.- Handle-ID: http://hdl.handle.net/2042/70638

 

Carnets Geol., vol. 19, nº 19

Fri, 27 Dec 2019 11:24:13 GMT

Olev Vinn, Carolina Zabini & Luiz Carlos Weinschütz.- Ichnofossils associated with lingulide shells from the Lower Permian of Brazil.- Lingulides from Lower Permian of Brazil (24% substrates) showed signs of bioerosion in form of multiple small shallow pits that resemble incomplete Oichnus paraboloides borings. A single lingulide valve showed a centrally located large circular predatory Oichnus simplex boring. Several lingulide shells (c. 21%) show small Arachnostega traces in their interior. The diameter of Arachnostega burrows is relatively constant. These burrows are more similar to juvenile stages of Arachnostega gastrochaena and do not form well-developed meshwork of tunnels. This is the first record of Arachnostega from the interior of lingulide shells and indicates that even very small lingulide shells were suitable substrates for cryptic organisms.- Handle-ID: http://hdl.handle.net/2042/70636

 

Carnets Geol., vol. 19, nº 18

Mon, 11 Nov 2019 11:20:19 GMT

Yves Plusquellec & Françoise P. Bigey.- New data on the intergrowth of Rugosa-Bryozoa in the Lower Devonian of North Gondwana.- Numerous and generally well-preserved examples of the intergrowth Rugosa-Bryozoa from the Upper Pragian and Lower Emsian of the Armorican Massif (Châteaulin and Laval synclinoria), France, and from the Upper Emsian of the Ougarta Mountains, Erg Djemel, Algeria, are described. In the Armorican Massif, the corallites of a rugosan Tryplasmatidae? are intergrown with Ceramoporidae bryozoan close to Crepipora, exceptionally with an unidentified Fistuliporidae (likely a new genus), whereas in Ougarta the coral is not identifiable and is associated with a Fistuliporidae assigned to Fistulipora. Although mainly left in open nomenclature, the material is fully described (structure and microstructure) and illustrated (calcitic skeleton and natural moulds) for the first time. In addition, the presence of Ceramoporidae in the Lower Devonian is clearly established. The evaluation of the association is briefly discussed and a mutualistic relationship supported.- Handle-ID: http://hdl.handle.net/2042/70538

 

Carnets Geol., vol. 19, nº 17

Thu, 10 Oct 2019 11:11:27 GMT

Silviu O. Martha, Kei Matsuyama, Joachim Scholz, Paul D. Taylor & Gero Hillmer.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Institute in Frankfurt. Part 2 - Ctenostomata and non-ascophoran Cheilostomata.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Research Institute in Frankfurt am Main, Germany is a world-renowned collection of great scientific value. It is the world's largest collection of fossil bryozoans from the Upper Cretaceous and Paleocene and a unique archive documenting the evolution of this phylum of marine invertebrates during this time interval in the Boreal Chalk Sea that extended from the British Isles to the Aral Sea in Central Asia. The Voigt Collection contains over 300,000 specimens and was relocated to the Senckenberg Institute in 2005 according to the bequest of Ehrhard Voigt. As a result of a DFG-funded project, we present here a three-part type catalogue of the holotypes and neotypes of 256 bryozoan species in the Voigt Collection, of which this is Part 3. In total over the three parts, 247 species are re-illustrated but the name-bearing type specimens of 20 species are missing and no material could be found for 9 species. Two species, described as ctenostome bryozoans by Ehrhard Voigt, are questionable, while a further three 'ctenostome' species and one 'ctenostome' genus are considered as ichnotaxa.- Handle-ID: http://hdl.handle.net/2042/70501

 

Carnets Geol., vol. 19, nº 16

Thu, 10 Oct 2019 11:16:51 GMT

Olimpiu Neam?u, Ioan I. Bucur, R?zvan Ungureanu & Cristian Victor Mircescu.- Upper Jurassic-Lower Cretaceous limestones from the H?ghima? Massif (Eastern Carpathians, Romania): Microfacies, microfossils and depositional environments.- The H?gima? Massif provides important data for reconstructing the geological evolution of the Transylvanian Carbonate Platform. This unit is present nowadays in the basement of the Transylvanian Depression and as large-scale olistoliths, which crop out in various locations in the Eastern Carpathians and Apuseni Mountains. They contain a large variety of microfacies as well as microfossil assemblages partly encompassing the Jurassic/Cretaceous boundary. This study presents a detailed account of uppermost Jurassic-lowermost Cretaceous limestones from the Lapo? Valley (H?ghima? Mountains) containing two distinct successions separated by a fault. The first succession contains platform margin and inner platform deposits (subtidal, intertidal) whereas the second one consists of inner platform deposits (shallow-subtidal to peritidal carbonates). The Upper Jurassic Stramberk-type facies is overlain by lower Berriasian regressive peritidal limestones. The upper Berriasian-? lower Valanginian consists mainly of inner platform deposits. They contain alternating, high and low-energy carbonates with rare calpionellids and calcispheres. The age assignment is based on a rich and diverse micropaleontological assemblage containing similar biota reported from other regions of the Tethysian Realm.- Handle-ID: http://hdl.handle.net/2042/70499

 

Carnets Geol., vol. 19, nº 15

Thu, 10 Oct 2019 11:10:03 GMT

Silviu O. Martha, Kei Matsuyama, Joachim Scholz, Paul D. Taylor & Gero Hillmer.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Institute in Frankfurt. Part 2 - Ctenostomata and non-ascophoran Cheilostomata.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Research Institute in Frankfurt am Main, Germany is a world-renowned collection of great scientific value. It is the world's largest collection of fossil bryozoans from the Upper Cretaceous and Paleocene and a unique archive documenting the evolution of this phylum of marine invertebrates during this time interval in the Boreal Chalk Sea that extended from the British Isles to the Aral Sea in Central Asia. The Voigt Collection contains over 300,000 specimens and was relocated to the Senckenberg Institute in 2005 according to the bequest of Ehrhard Voigt. As a result of a DFG-funded project, we present here a three-part type catalogue of the holotypes and neotypes of 256 bryozoan species in the Voigt Collection, of which this is Part 2. In total over the three parts, 247 species are re-illustrated but the name-bearing type specimens of 20 species are missing and no material could be found for 9 species. Two species, described as ctenostome bryozoans by Ehrhard Voigt, are questionable, while a further three 'ctenostome' species and one 'ctenostome' genus are considered as ichnotaxa.- Handle-ID: http://hdl.handle.net/2042/70498

 

Carnets Geol., vol. 19, nº 14

Thu, 10 Oct 2019 11:13:25 GMT

Rafel Matamales-Andreu.- Historical review together with stratigraphical and taphonomical considerations on the upper Pleistocene deposit of Arenal de son Servera (Mallorca, Balearic Islands).- The upper Pleistocene deposit of Arenal de son Servera is reviewed using data from earlier works and new considerations based on its stratigraphy and taphonomical aspects of the fossils. In the present study, five different kinds of facies are identified: [1] palaeosols with pebbles from the Miocene basement, [2] aeolianites, [3] foreshore deposits with thermophilous molluscan fossil fauna, [4] palaeosols resulting from the pedogenesis of the beach units, and [5] bioclastic channelled deposits eroding the underlaying units. The detailed taphonomical analysis revealed that the fossils enclosed in these rocks remained on the sea bottom for a significant amount of time, but they were not bioeroded, perhaps because a submerged sand bar repeatedly buried and exhumed them. In addition, the fact that Persististrombus latus shells are in their position of maximum stability allows to infer that they were washed up on the shore during moderately energetic events, possibly comparable to present-day ordinary storms. These two last points could be of interest to the field of coastal management, as they provide insight on the scope of physical changes these systems could undergo in the present warming of the Mediterranean.- Handle-ID: http://hdl.handle.net/2042/70497

 

Carnets Geol., vol. 19, nº 13

Thu, 10 Oct 2019 11:08:22 GMT

Silviu O. Martha, Kei Matsuyama, Joachim Scholz, Paul D. Taylor & Gero Hillmer.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Institute in Frankfurt. Part 1 - Introduction and Cyclostomata.- The bryozoan collection of Prof. Dr Ehrhard Voigt (1905?2004) at the Senckenberg Research Institute in Frankfurt am Main, Germany is a world-renowned collection of great scientific value. It is the world's largest collection of fossil bryozoans from the Upper Cretaceous and Paleocene and a unique archive documenting the evolution of this phylum of marine invertebrates during this time interval in the Boreal Chalk Sea that extended from the British Isles to the Aral Sea in Central Asia. The Voigt Collection contains over 300,000 specimens and was relocated to the Senckenberg Institute in 2005 according to the bequest of Ehrhard Voigt. As a result of a DFG-funded project, we present here a three-part type catalogue of the holotypes and neotypes of 256 bryozoan species in the Voigt Collection, of which this is Part 1. In total over the three parts, 247 species are re-illustrated but the name-bearing type specimens of 20 species are missing and no material could be found for 9 species. Two species, described as ctenostome bryozoans by Ehrhard Voigt, are questionable, while a further three 'ctenostome' species and one 'ctenostome' genus are considered as ichnotaxa.- Handle-ID: http://hdl.handle.net/2042/70493

 

Carnets Geol., vol. 19, nº 12

Thu, 10 Oct 2019 11:04:00 GMT

Mariusz A. Salamon.- A new prospect in crinoid (Crinoidea, Echinodermata) research: An example from the Lower Jurassic of Montenegro.- Lower Jurassic (Hettangian-Pliensbachian) shallow-marine ooidal limestones of southern Montenegro contain a large number of isocrinid ossicles. They are assigned to the following taxa: Isocrinus psilonoti (Quenstedt), Isocrinus sp., and Pentacrinites cf. fossilis Blumenbach. The echinoderm assemblage also yields cyrtocrinid ossicles (Cotylederma sp., Cyrtocrinina indet.) and echinoid spines (only spotted in thin sections); however, these elements are rare. Given the fact that the recorded assemblage comes from a single locality, there is a growing need for further research that will require intense sampling to compile and complete the faunal list of crinoids and other echinoderm taxa.- Handle-ID: http://hdl.handle.net/2042/70491

 

Carnets Geol., vol. 19, nº 11

Thu, 08 Aug 2019 11:01:51 GMT

Petr V. Fedorov & Anna V. Koromyslova.- New findings of the genus Revalotrypa, the oldest bryozoan genus of Baltoscandia, in north-western Russia.- New findings of esthonioporate bryozoans of the species Revalotrypa cf. inopinata, representing one of the oldest bryozoans of Baltoscandia, are described from an outcrop located in Leningrad Oblast' (north-western Russia). The colonies of this species are very small and were extracted from limestone-cemented nodules found in glauconitic sandstones of the lower part of the Joa Member (Paroistodus proteus conodont zone, lowermost Floian, Lower Ordovician). Combined X-ray microtomography and the examination of traditional thin sections under a stereomicroscope and a light microscope were used to study the morphology of this species.- Handle-ID: http://hdl.handle.net/2042/70296

 

Carnets Geol., vol. 19, nº 10

Thu, 08 Aug 2019 10:57:51 GMT

Sihem Salmi-Laouar, Bruno Ferré & Riadh Aouissi.- Abondance d'Aspidiscus cristatus (Lamarck, 1801) dans la Formation des Marnes de Smail de la région de Batna (NE d'Algérie) : Une espèce caractéristique pour le Cénomanien moyen. Abundant occurrence of Aspidiscus cristatus (Lamarck, 1801) in the "Marnes de Smail" Formation from the Batna area (NE-Algeria): Index species for the Middle Cenomanian.- Les marnes cénomaniennes de la région de Batna (nord-est de l'Algérie) montrent plusieurs niveaux fossilifères, à faune très diversifiée. Parmi les fossiles présents en abondance et en bon état de conservation figure Aspidiscus cristatus (Lamarck, 1801). Cette espèce de polypier a été rattachée à la famille des Latomeandridae Alloiteau, 1952, en raison de la présence de pennulae et de perforations concentrées sur le bord interne des septes. Dans les coupes étudiées, Aspidiscus cristatus se rencontre dans des niveaux allant de la Zone à Cunningtoniceras inerme à la Zone à Acanthoceras amphibolum, avec une relative abondance dans la Zone à Acanthoceras cf. rhotomagense. Cette espèce est, par conséquent, un bon marqueur du Cénomanien moyen de la région de Batna. Nous donnons ici une description paléontologique et discutons des cadres environnemental et paléogéographique de cette espèce. En effet, la morphologie externe de son test, convexe sur la face supérieure, plane à concave sur la face inférieure, évoque une adaptation à des environnements marins de faible énergie, de substrat vaseux et au taux de sédimentation élevé. La répartition paléogéographique de cette espèce, avec des spécimens de taille souvent plus grande sur les marges sud et est du domaine téthysien que sur la marge nord, témoigne d'un gradient thermique et d'une zonation climatique spécifiques, avec des eaux relativement plus chaudes sur la marge sud-téthysienne au Cénomanien, favorisant une bio-érosion beaucoup plus fréquente et plus poussée des spécimens fossiles des régions sud-téthysiennes que celle affectant les spécimens des régions septentrionales de la Téthys. Abundant occurrence of Aspidiscus cristatus (Lamarck, 1801) in the "Marnes de Smail" Formation from the Batna area (NE-Algeria): Index species for the Middle Cenomanian.- The Cenomanian marls of the Batna region (NE Algeria) display several fossiliferous beds with highly diversified fauna. Among the abundant and well-preserved fossils stands out Aspidiscus cristatus (Lamarck, 1801). This coral taxon is assigned to the Family Latomeandridae Alloiteau, 1952, due to the presence of pennulae and inner septal margins with slight perforations. In the studied sections Aspidiscus cristatus is found in beds ranging from the Cunningtoniceras inerme Zone to the Acanthoceras amphibolum Zone, with a relative abundance within the Acanthoceras cf. rhotomagense Zone. This species is subsequently a good marker for the Middle Cenomanian in the Batna district. We give herein a systematic and paleontological description and discuss the paleoenvironmental and paleogeographic framework of this taxon. Actually the outer morphology of its test, with convex outer surface and planar to concave inner surface, suggests an adaptation to mud-supported, low-energy marine environments with high sedimentary rate. The paleogeographic range of this taxon, with often larger-size specimens on the southern and eastern margins of the Tethysian Realm, than those on the northern margin, supports very peculiar thermal gradient and climactic zone, with relatively warmer waters on the southern Tethysian margin during the Cenomanian, favoring a more frequent and more effective bioerosion on fossil specimens from southern Tethysian areas than that affecting specimens from northern Tethysian areas.- Handle-ID: http://hdl.handle.net/2042/70294

 

Carnets Geol., vol. 19, nº 09

Thu, 08 Aug 2019 10:47:41 GMT

Stéphane Bersac & Didier Bert.- The lower Aptian ammonites of the Les Ferres Aptian Basin (Lower Cretaceous, Southeast of France). Part I: Introduction and biostratigraphy.- On the southern margin of the Vocontian Basin (SE France), for taphonomic reasons (fragmentation, reworking, pyritization), lower Aptian (Lower Cretaceous) deposits of the interval between the Deshayesites deshayesi and Dufrenoyia furcata zones are usually not suitable for studying the late ontogenetic developments of ammonites (fossil cephalopods). In the vicinity of the village of Les Ferres (Department of the Alpes-Maritimes, SE France), a relatively thick sedimentary succession with well-preserved ammonites, representative of the zones mentioned above, is found in a small basin called the "Les Ferres Aptian Basin" (LFAB). The 1262 ammonites collected or studied in situ are dated from the Deshayesites forbesi Zone through the top of the Dufrenoyia furcata Zone. This study presents the lithostratigraphy, biostratigraphy derived from these ammonites, and the respective range of these taxa. This is an introductory contribution to any future palaeontological study of the lower Aptian ammonites in the Les Ferres area. The lithologic unit overlying the Hauterivian-Aptian limestones is introduced herein as the Les Graous Formation. It is subdivided in three members, from bottom to top: 1) the Combe de Joinet Member, 2) the Pont de la Cerise Member, and 3) the Les Graous Member. In addition, two remarkable levels are identified: the Ammonitoceras level (outstandingly abundant) and the Toxoceratoides bed.- Handle-ID: http://hdl.handle.net/2042/70292

 

Carnets Geol., vol. 19, nº 08

Thu, 08 Aug 2019 10:44:35 GMT

Arnaud Brignon.- The nomenclatural status of Palaeothrissum inaequilobum Blainville, 1818, P. parvum Blainville, 1818, and Aeduella blainvillei (Agassiz, 1833) (Actinopterygii, Aeduellidae).- It is shown that the species names Palaeothrissum inaequilobum Blainville, 1818, and P. parvum Blainville, 1818, from the Lower Permian (Asselian) of Muse, near Autun (Saône-et-Loire department, France) are senior synonyms of the widely used species name, Aeduella blainvillei (Agassiz, 1833). In the interest of nomenclatural stability, conditions exist which allow reversal of precedence as stated in Article 23.9.1 of the International Code of Zoological Nomenclature. Thus the species name Aeduella blainvillei (Agassiz, 1833) is regarded as valid, qualifying as a nomen protectum, whereas Palaeothrissum inaequilobum Blainville, 1818, and P. parvum Blainville, 1818, are invalid, qualifying as nomina oblita. Some of the specimens from the type series upon which P. inaequilobum, P. parvum and Aeduella blainvillei were erected, are identified.- Handle-ID: http://hdl.handle.net/2042/70290

 

Carnets Geol., vol. 19, nº 07

Fri, 31 May 2019 10:07:43 GMT

Bruno Granier.- Observations on some Actinoporellas (Chlorophyta, Polyphysaceae). Revision of the Jacques Emberger Collection. Part 1.- On the occasion of the inventory of the J. Emberger Collection, specimens from the "Lower Cretaceous" (Valanginian and Hauterivian) of Algeria, which are referable to the genus Actinoporella (Gümbel in Alth) and which were earlier identified to its type-species A. podolica (Alth) by Conrad et al., are re-examined. They correspond to two discrete species, one of which could be a junior synonym of A. podolica, a synonymy that remains pending because it would require a new sampling at the original locality in western Ukraine some 140 years after the original specimens, now lost, were collected. Regarding their age ascription, they are Tithonian and/or Berriasian in age, i.e., latest Jurassic (sensu Oppel) in age, not earliest Cretaceous. In addition to these two Actinoporellas, a third discrete species, initially described as Clypeina nigra (Conrad & Peybernès), but later referred to the genus Actinoporella, is revised. New data justify its re-ascription to the genus Bakalovaella Bucur. Finally, it is now confirmed that both the Polyphysaceae and the modern Dasycladaceae derive from the Diploporaceae either directly or indirectly through the ancestral Dasycladaceae.- Handle-ID: http://hdl.handle.net/2042/70196

 

Carnets Geol., vol. 19, nº 06

Fri, 31 May 2019 10:06:00 GMT

Koorosh Rashidi & Felix Schlagintweit.- New data on some type-species of Maastrichtian-Paleocene Dasycladales (Green algae) from Iran. Part I. Pseudocymopolia Elliott, 1970.- Pseudocymopolia anadyomenea, the type-species of the genus, was described by Elliott (1959) from the Maastrichtian of Iraq. Besides the type-locality, it was also recorded from the upper Maastrichtian Tarbur Formation of Iran, from Afghanistan and Tibet. A rich but moderately preserved material is analyzed herein, evidencing the presence of two discrete species: P. anadyomenea and P. acuta n. sp. The new species is characterized by its thallus morphology displaying tapering, keeled segment margins. Besides the morphology, both are also distinguished by biometric parameters such as the outer diameter (D), inner diameter (d), and the d/D ratio. All other Lower Cretaceous species of Pseudocymopolia as well as the Maastrichtian P. anadyomenea have rounded segment margins. Both taxa from the Tarbur Formation occur in inner platform quiet water depositional settings whereas the Lower Cretaceous representatives typically characterize platform margin deposits.- Handle-ID: http://hdl.handle.net/2042/70194

 

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