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1.
The ammonoid subfamily Peltoceratinae is a well-constrained group restricted to the Middle Upper Jurassic; it had a near global distribution. In Kutch (India), they were the most important marine macroinvertebrate group during the upper Callovian–lower Oxfordian. Previous reports suffered from excessive splitting due to failure to account for the large intraspecific variability and sexual dimorphism of these ammonoids. The present systematic revision, based on numerous specimens including many near-complete adult specimens, enables to recognize and describe three species of the genus Peltoceras (P. athleta, P. ponderosum, and P. kumagunense) and two species of the genus Peltoceratoides (P. semirugosus and P. propinquus), as well as identifying their macroconchs and microconchs. We rediscovered Peltoceras athleta, which was previously described by Waagen (1875) but often overlooked by subsequent workers. We were able to identify several morphs within this species that are stunningly similar with those previously reported from France. The presence of P. athleta sensu stricto prompted us to reinstate the Athleta Zone in Kutch, improving intercontinental biostratigraphic correlation. Also, it highlights that the genus Peltoceras has a different biostratigraphic longevity in Kutch: in Europe it is restricted to the upper Callovian, whereas in India it also occurs in the lower Oxfordian.  相似文献   

2.
The succession of early species of the genus Kepplerites is established in the Upper Bathonian-Lower Callovian beds of Central Russia and compared with the ammonoid succession of East Greenland and Western Europe. Late Bathonian members of the genus Kepplerites from the Middle Volga Region are generally similar, though not identical to those from Greenland, whereas the Early Callovian Kepplerites species and their immediate Bathonian ancestors are represented by species common to all three regions. The analysis of the ammonoid distribution suggests a connection between the East Greenland and Central Russian marine basins in the Early and Middle Bathonian and in the Early Callovian, and their short-term isolation in the Late Bathonian. A new species, Kepplerites (Kepplerites) aigii sp. nov., is described from the Upper Bathonian (keuppi Zone) of the Alatyr River basin (Middle Volga Region).  相似文献   

3.
《Geobios》1988,21(5):567-609
The genus Pachyerymnoceras, with four new species,is described for the first time in Western Algeria. The genus first appears in the Middle Callovia (Coronatum Zone) as in Saudi Arabia. It is represented in the Saida region by uncommon P. praecox nov. sp. followed during the Upper Callovian (Athleta Zone) by specimens belonging to P. flamandi sp. nov., P. kmerense nov. sp. and P. saidense nov. sp. Every species is represented by a dimorphic pair.Pachyceratidae are put into Perisphinctaceae. If Pachyerymnoceras arises from Erymnoceras, a genus suddenly appearing during the Middle Callovian on northern and southern Tethyan borders, the origin of Erymnoceras is still unknown. Three phylogenetic hypothesis are considered here. Erymnoceras may have evolved during Lower Callovian: 1) from serpenticonic Tethyan Pseudoperisphinctinae like Choffatia (Subgrossouvria); 2) from Tulitids via ellipticoncic Bullatimorphites (Kheraiceras); 3) through a double lineage arisen in Subboreal and Tethyan platyconic Proplanulitids.Pachyceratids have a wide paleobiogeographic distribution in NW Europe and on the Tethyan margins. The genus Pachyerymnoceras evolves in Ethiopian Province of the Tethyan Realm. Some species migrate into Indo-Malagasian Province and others, through the south Tethyan border came to Europe were they are found restricted to Upper Callovian (Athleta and Lamberti Zones). Therefore this migration has a duration of two or even three zones.  相似文献   

4.
Peter M. Galton 《Geobios》1980,13(6):825-837
Hitherto the earliest positive record of ankylosaurs(armored dinosaurs) has been from beds well up in the Lower Cretaceous; in fact, however, specimens referable to the ankylosaurian family Nodosauridae are present in the Middle and Upper Jurassic of England: from the Middle Callovian [partial mandible Sarcolestes leedsiLydekker]], the Upper Oxfordian [femur Cryptodraco eumerus (Seeley)), maxilla Priodontognathus phillipsii (Seeley))], and the Upper Tithonian [caudal vertebra, tooth]. The Tithonian tooth and those of Priodontognathus are large and similar to those of the nodosaurids Priconodon and Sauropelta (Lower Cretaceous, U.S.A.). The incomplete mandible of Sarcolestes is similar to that of Sauropelta with a dermal scute fused to the lateral surface, and a tooth row extending to the anterior end of the jaw; an unusual feature is the caniniform first tooth. The quadrupedal ankylosaurs and stegosaurs probably represent separate evolutionary lines that extend back at least into the Lower Jurassic, and both lines probably evolved from ornithopod dinosaurs that were bipedal. Nodosaurid ankylosaurs occur in Europe from the Middle Jurassic to Late Cretaceous and probably reached North America via a filter route in the early Cretaceous.  相似文献   

5.
A new species of the genus Kinkeliniceras Buckman (K. oppelin. sp.) from the Upper Callovian (Jurassic) horizon of the HaboHill in Kutch is described and illustrated. The form is characterizedby Hubertoceras-like inner whorls Kinkeliniceras has been shown to range throughout the Callovian. (Received 17 July 1979;  相似文献   

6.
7.
Two specimens of the Middle Jurassic ammonite genusReineckeia (sensu lato) have been found in the lowest beds of the Pachchham (Patcham) Limestones exposed in the core of the Jumara Dome, Kachchh (Kutch), Gujarat, western India. The stratigraphy is described in detail and the age bracketed to lie between latest Late Bathonian and Middle Bathonian, older than any previously described examples of this genus, either in India or in Europe (middle Early Callovian). The new finds are compared with other known pre-Callovian Reineckeiidae, notably those of the eastern borders of the Pacific, but the relationships are not close. The phylogenetic consequences are briefly discussed. The roots of the Reineckeiidae continue to lie hidden.  相似文献   

8.
Jacques Thierry 《Geobios》1980,13(5):759-765
The revision of Waagen's figured specimens from Kutch (India) shows that “Stephanoceras arenosum” after being considered as a Macrocephalites and than as a Mayaites is really a Pachyceras. This species is morphologically very close to the microconch of Pachyceras la landeanum (d'ORBIGNY) from Lamberti zone (Upper Callovian) of Western Europ. Its validity and that of others species of this genus collected in India is discussed. Its importance for stratigraphical correlations between european and indo-malagasy provinces is pointed out.  相似文献   

9.
Here we present and describe comparatively 25 talus bones from the Middle Pleistocene site of the Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain). These tali belong to 14 individuals (11 adult and three immature). Although variation among Middle and Late Pleistocene tali tends to be subtle, this study has identified unique morphological characteristics of the SH tali. They are vertically shorter than those of Late Pleistocene Homo sapiens, and show a shorter head and a broader lateral malleolar facet than all of the samples. Moreover, a few shared characters with Neanderthals are consistent with the hypothesis that the SH population and Neanderthals are sister groups. These shared characters are a broad lateral malleolar facet, a trochlear height intermediate between modern humans and Late Pleistocene H. sapiens, and a short middle calcaneal facet. It has been possible to propose sex assignment for the SH tali based on their size. Stature estimates based on these fossils give a mean stature of 174.4 cm for males and 161.9 cm for females, similar to that obtained based on the long bones from this same site.  相似文献   

10.
11.
The rhynchonellid brachiopod species Cryptopora lovisati(Dreger, 1911) has been identified in the Middle Miocene sandy deposits of France, and its ontogeny and variability are described. This is the first record of the genus Cryptopora Jeffreys from France, although several species of Cryptopora have been already reported from other regions of Europe. Being known since the Lower Palaeocene, Cryptopora is widely distributed in modern seas, ranging from about 60 m down to over 4000 m, and is represented by six extant and about 12 fossil species. C. lovisati has been interpreted as relatively shallow water species living attached to the sediment by a long pedicle. The affinity between C. lovisati and Recent C. curiosa Cooper is discussed.  相似文献   

12.
Perisphinctes Waagen, 1869 is an important genus of the Oxfordian. In many areas the taxon has been excessively and subjectively split. Based on the material collected in Kutch (India), including the type specimens, we have grouped eight species previously described as distinct into one biological species, Perisphinctes indogermanus Waagen, 1875. It is characterized by strong sexual dimorphism. Macroconch shows high intraspecific variability. Microconch is previously described from Kutch in different generic names. Thirteen species of Dichotomosphinctes Buckman, 1926, Perisphinctes Waagen, 1869 and Lithacoceras Hyatt, 1900 are considered here as microconch which is lappeted. The precise age of P. indogermanus is disputed. A detailed stratigraphic analysis of several sections in this study suggests that the species ranges from early to middle Oxfordian. Perisphinctes indogermanus is distinct from other contemporary species of the world and abundant in the Indo-Madagascan Province. Kutch population of P. indogermanus has developed virgatotome style of ribbing in juvenile stage. During the middle Oxfordian marine transgression, the species along with many other ammonites of deeper habitat of the mainland basin reached the shallow shelf of eastern fringe of the Kutch Sea. Being peripherally isolated, it soon underwent an adaptive radiation that resulted in the origination of a new family Ataxioceratidae Buckman, 1921 whose members have neotenously retained the virgatotome ribbing in adult stage. The ataxioceratids later migrated to Europe and flourished during the Kimmeridgian.  相似文献   

13.
The Middle Bathonian to Middle Oxfordian interval in the Eastern External Subbetic (Betic Cordillera, SE Spain) is characterized by Ammonitico Rosso facies including various stratigraphic breaks. Five hardground-bounded units are recognized in relation to hiatuses in the ammonite record at the following stratigraphic boundaries: Hg1 (Lower–Middle Bathonian), Hg2 (Middle–Upper Bathonian), Hg3 (Lower–Middle Callovian), Hg4 (Middle–Upper Callovian), and Hg5 (Callovian–Oxfordian). Interesting features of these hardgrounds include their microfacies, ferruginous crusts and macro-oncoids, taphonomy of macroinvertebrates, trace fossils, neptunian dykes, and the hiatuses associated with each of them. The main hardgrounds (Hg1, Hg2, and Hg5) contain trace fossils of the Cruziana and Trypanites ichnofacies as well as abundant fossil macroinvertebrates with taphonomic features evidencing corrasion, early diagenesis, and reworking, indicating substrate evolution from softground to hardground. Neptunian dykes affected the trace fossils and ammonoid moulds, and their walls and the hardground surfaces were colonized by ferruginous microbial crusts. These features are characteristic of the External Subbetic pelagic swells, where the absence of sedimentation, sediment bypassing and erosion, and early diagenesis during relative sea-level falls produced hardgrounds. The neptunian dykes are indicative of tectonic activity in the areas of pelagic swells. Ferruginous crusts and macro-oncoids developed only on hardground surfaces and neptunian dykes walls prior to deposition of condensed bioclastic beds, which are interpreted as the first deposits after hardground development and are related to the onset of transgression. The varying ranges of the gaps as well as lateral facies changes are related to different local paleobathymetry controlled by the activity of listric faults.  相似文献   

14.
《Annales de Paléontologie》2017,103(3):197-215
Despite the stratigraphical significance of dinoflagellate cysts as reliable markers for correlating and dating Jurassic–Cretaceous strata, investigations into this palynomorph group in the southern Tethyan Realm, specifically northwest Africa, are sparse and somewhat parochial. Most research on Jurassic dinoflagellate cysts is focussed on European depocentres in the Boreal and Sub-Boreal realms. This study is on biostratigraphical data from two petroleum boreholes (MSD1 and KDH1) drilled during 1985 in the Guercif Basin, northeast Morocco by ONAREP (Office National de Recherche et d’Exploitation Pétrolier), now ONHYM (Office National des Hydrocarbures et des Mines). These boreholes penetrated a thick siliciclastic succession, attributed to the Middle and Upper Jurassic, below Miocene marls. Over sixty dinoflagellate cyst taxa were identified. Four dinoflagellate cyst biozones, named GI to GIV, are established for the late Bathonian to early Oxfordian interval. These biozones are defined on the basis of the first appearance datum (FAD) and/or the last appearance datum (LAD) of some biomarker taxa which have wide geographical distributions. These are: Ctenidodinium combazii and Ctenidodinium sellwoodii for the GI Biozone (late Bathonian–early Callovian); Ctenidodinium continuum and Meiourogonyaulax caytonensis for the GII Biozone (middle Callovian); Gonyaulacysta centriconnata and Wanaea thysanota for the GIII Biozone (late Callovian–earliest Oxfordian); and Liesbergia liesbergensis and Systematophora penicillata for the GIV Biozone (early Oxfordian). These biozones are correlated to those already established for the respective intervals in other palaeogeographic regions, such as the Boreal, Sub-boreal and Tethyan realms.  相似文献   

15.
Three new species of the Middle Jurassic stenolaemate bryozoans of the genera Reptomultisparsa d’Orbigny and Microeciella Taylor et Sequeiros are described: R. saratovensis sp. nov. and M. seltseri sp. nov. from the Lower Bathonian and the Upper Callovian of the Saratov Region, respectively, and R. stupachenkoi sp. nov. from the Middle Callovian of the Moscow Region. Some specific features of their astogeny and colonial morphology are discussed.  相似文献   

16.
New bryozoans from the Middle Callovian (Middle Jurassic) of Moscow city (Reptomulticava pileola sp. nov.) and the Moscow Region (Spirodella radiolobata gen. et sp. nov.) and from the Middle Oxfordian (Upper Jurassic) of the Kostroma Region (Hyporosopora mittai sp. nov.) are described. All three bryozoans belong to the class Stenolaemata. Some features of their colonial organization and environmental conditions are discussed.  相似文献   

17.
A new specimen of the widespread Middle Jurassic to Lower Cretaceous Asian gonipholidid crocodilian genus Sunosuchus is described on the basis of a partial skeleton from the Upper Toutunhe Formation (Middle Jurassic, ?Bathonian-Callovian) of Liuhonggou, SW of Urumqi, Xinjiang Uygur Autonomous Region, People’s Republic of China. The specimen is represented by a partial mandible, teeth, vertebrae, limb and girdle bones and osteoderms. It can be distinguished from other nominal species of the genus by a unique combination of characters: slightly heterodontous dentition, strongly sculptured posteroventral part of the mandible, short fenestra mandibularis, convex dorsal surface of the retroarticular process, keeled cervical vertebral centra and ventral osteoderms with a distinctive sculpture of wide pits and narrow ridges. The heterodontous dentition is a potential autapomorphy of this form. The new specimen is closest in morphology to material described recently from the Callovian of Kirghisia as Sunosuchus sp. It represents the second Middle Jurassic record of the genus, the first crocodile from the Toutunhe Formation, the first substantial crocodile find from the Mesozoic of the Southern Junggar Basin, and the first Middle Jurassic record of Sunosuchus from China. This extends both the paleobiogeographical distribution of the genus in Asia and its stratigraphic distribution in China considerably.  相似文献   

18.
The space of Devonian time considered in this paper corresponds to the uppermost part of the Famennian or the latest Famennian as a fourfold subdivision of the stage, usually called by many authors Strunian in neritic facies and Wocklumeria Stufe or Wocklumian in pelagic facies. Here, we examine the biostratigraphical value of certain brachiopod genera and species as bio-markers of the uppermost Famennian throughout the world (Europe, the former USSR, Middle East, Asia, North America, North Africa, and Australia). We have focused our study for species which stratigraphical range has been firmly established in correlation with the conodont biozones (Upper expansa, Early, Middle and Late praesulcata), the ammonoid biozones (do VI = “Wocklumeria Stufe”), or the foraminifera biozones (kobeitusana Zone). Other data for which the stratigraphical range is not based on standard biozonation are provided in the annex. The brachiopod bio-markers discussed in this paper belong to 14 Productidina genera (Acanthatia, Araksalosia, Ericiata, Hamlingella, Mesoplica, Nigerinoplica, Orbinaria, Ovatia, Rugauris, Semiproductus, Sentosia, Spinocarinifera, Steinhagella, Whidbornella), 7 Rhynchonellida genera (Araratella, Centrorhynchus, Hadyrhyncha, Megalopterorhynchus, Novaplatirostrum, Rozmanaria, Tchanakhtchirostrum), 13 Spiriferida genera (Brachythyris, Cyrtospirifer, Dichospirifer, Eochoristites, Imbrexia, Parallelora, Prospira, Rigauxia, Sphenospira, Tenisia, Toryniferella, Tylothyris, Voiseyella) and one Spiriferinida genus (Syringothyris). Other orders have not been studied in this paper. The main features of the uppermost Famennian brachiopod taxa represented in this paper are commented. All these taxa are listed as completely as possible throughout the world (with complements in the annex). A quick summary of the geographic distribution of the more represented taxa is given in conclusion.  相似文献   

19.
Gabriel A. Gill 《Geobios》1982,15(2):217-223
Epistreptophyllum, a rather common coral in the Middle and Late Jurassic of Europe and Asia, is generally regarded as solitary. Some specimens collected in Late Callovian beds of the northern Negev, Israel, show genuine branching which would suggest a colonial habit for this genus. Eventual convergence between the genera Epistreptophyllum, Haplaraea and Diplaraea is presumed.  相似文献   

20.
Vampyronassa rhodanica nov. gen. nov. sp., Vampyromorpha (Cephalopoda, Coleoidea) from the Lower Callovian of la Voulte-sur-Rhône (Ardèche, France). The Vampyromorpha, an order of cephalopods closely related to Octopoda, have been yet undubitably identified only in recent time, always in deep oceanic waters. Their occurrence since the Middle Jurassic is evidenced by about twenty specimens from the Lower Callovian of la Voulte-sur-Rhône (Ardèche), which exhibit vampyromorph fundamental features : eight sessile arms showing one row of suckers with bordering cirri, a web uniting the arms, a pair of brachial tentacles, well shaped lateral eyes, an internal uncalcified supporting organ (gladius), a pair of supero-posterior fins, two postero-dorsal light-organs, no ink-sac. These specimens, here assigned to the new genus and species Vampyronassa rhodanica, still differ from recent Vampyromorpha by their two first dorsal sessile arms clearly longer than the others, their more important funnel and their longer and slightly more spindle-like body. This characteristic Middle Jurassic vampyromorph leads to admit a much older origin for this cephalopod order. The probably mesopelagic mode of life of this new vampyromorph is then tentatively examined. Critical arguments about the assignment to Vampyromorpha of three large teuthid-like species from the Upper Jurassic of Germany are developed.  相似文献   

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