Late Kungurian Research Articles

Depositional environments and plant communities in the exceptional context of the Kungurian megacaldera of the Athesian Volcanic Group (Southern Alps, N-Italy)

We used a combined approach (lithofacies and palynology) and multivariate analyses to reconstruct the different depositional environments and changes in the plant communities throughout the middle to late Kungurian in the tropical Pangea. The late Paleozoic terrestrial biotas underwent changes under the pressure of a general aridification trend and a warming event that changed biota composition favoring drought-tolerant taxa during the Artinskian. Few studies integrate the different terrestrial ecosystem components to reconstruct palaeoenvironments and climate changes throughout the Cisuralian (early Permian). We analyzed several sedimentary successions of different stratigraphic positions intercalated in well-dated volcanic units of the megacaldera of the Athesian Volcanic Group (Southern Alps, northern Italy). The obtained palynofacies and quantitative sporomorph records with an exceptional high resolution (∼10 Ma) evidence a palaeoenvironmental/climatic change in the plant communities from the middle to the late Kungurian. The late Kungurian shows a higher diversity in the plant communities with a dominance of seed ferns and a higher relative abundance of xeromorphic-hygromorphic sporomorph taxa. This suggests the presences of more stable and putatively more humid environmental conditions in respect to the middle Kungurian. Furthermore, a direct comparison between lithofacies and all primary components of the palynofacies assemblages permits to characterize lacustrine and alluvial depositional environments since these studies are underrepresented for terrestrial environments.

Late Kungurian Radioisotope Age of the Boundary Between the Balakhonka and Kolchugino Groups in the Kuznetsk Basin (Western Siberia, Russia) – Additional Evidence for the Validity of the Ufimian Stage of the East European Permian

This article discusses the Late Kungurian radioisotopic age (276.9 ± 0.4 Ma) of the middle part of the Starokuznetsk Formation (Kuznetsk Subgroup, Kolchugino Group) of the Kuznetsk Basin determined by chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS). The analysis of the biostratigraphic data confirms that the layer dated belongs to the interval in which the Balakhonka Flora (cordaitoid) was replaced by the Kolchugino Flora (fern-pteridosperm-cordaitoid). This indicates that the change from the Balakhonka Flora to the Kolchugino Flora in the low latitudes of Angaraland took place during the Late Kungurian. The data obtained were used for direct correlation of the lower part of the Kolchugino Group with the Upper Kungurian of the International Chronostratigraphic Chart. Similar sequences of non-marine bivalve assemblages in the Permian successions of Angaraland (giant Prokopievskia, Khosedaella-Redikorella-Palaeomutela, and dominant Palaeomutela) and Eastern Europe (giant Sinomya, Palaeomutela-Khosedaella-Redikorella, and dominant Palaeomutela) further support the validity of the correlation of the Kuznetsk Subgroup with the Ufimian Stage. The placement of the lower boundary of the Kolchugino Group in the upper part of the Kungurian Stage of the International Chronostratigraphic Scale raises the question of the continuation of the Ufimian Stage as an independent straton in the East European Stratigraphic Scale. Its lower boundary coincides with the beginning of the change in the Balakhonka and Kolchugino Flora in the low latitudes of Angaraland, as well as with the faunal exchanges between the Euramerican and Angarian non-marine bivalve assemblages.

U-Pb Dating of the Kolchugino Group Basement (Kuznetsk Coal Basin, Siberia): Was the Change in Early–Middle Permian Floras Simultaneous at Different Latitudes in Angaraland?

The Kuznetsk Basin (Kuzbass) is one of the largest coal basins in Siberia and a reference area for the ancient Angaraland continent. The proximity of the Kuzbass and Siberian Platform caused their biotic similarities in the Late Palaeozoic. However, due to biota endemism, the Kuzbass Upper Palaeozoic does not correlate directly with the International Chronostratigraphic Chart (ICC). This paper discusses radioisotopic (CA-ID-TIMS) dating of zircons from a volcanic tuff located in the Starokuznetsk Formation (Fm). This level matches the interval of the Balakhonka/Kolchugino (B/K) floral change in Kuzbass, i.e., the gradual replacement of cordaitoid-dominated wet forests (Balakhonka flora) with more arid fern–pteridosperm–cordaitoid assemblages (Kolchugino flora). New age (276.9 ± 0.4 Ma) directly correlates the Starokuznetsk Fm with the Upper Kungurian of the ICC. We compared the Kuzbass data with data of the Western Verkhoyanie, where Middle Permian ammonoids (Sverdrupites assemblage) occur in strata recording the B/K floral change. The available (ICC) and new datings indicate the lag between the B/K floral change in low (Kuzbass) and high (Verkhoyanie) latitudes of Angaraland. The B/K floral change in the Kuzbass began in the early Late Kungurian and was completed by the end of this age. In contrast, the B/K floral change in Verkhoyanie began at the end of the Late Kungurian and was completed in the Late Wordian. The delay in the floral changes at different latitudes of Angaraland suggests that existing interregional correlations need further improvement.

Provenance shifts in bauxitic clay from Zibo, North China Craton, links tectonics and climate to environmental perturbation

Abstract In the eastern North China Craton, the Zibo bauxitic clay deposits are situated between Permian sandstones. These deposits exhibit distinct characteristics in two horizons. The lower horizon consists of disordered kaolinite with anhedral–subhedral, rounded morphologies that indicate a detrital origin. The upper horizon, however, contains ordered kaolinite. Detrital zircon grains in the lower horizon indicate a unimodal age spectrum with a mean age of ca. 290 Ma and εHf(t) values ranging from −20.8 to −6.0. These findings suggest a continental volcanic arc source on the northern margin of the North China Craton. In contrast, detrital zircon grains in the upper section exhibit a multi-modal detrital age spectrum with significant age peaks at 2500 Ma, 1850 Ma, and 310 Ma that originates from the local basement. The zircon dating establishes a maximum depositional age of ca. 280 ± 3 Ma, which indicates denudation of the source area in the northern North China Craton during the Artinskian stage. The relative abundance of detrital kaolinite indicates a warm and humid climate during the late Artinskian (ca. 283 Ma) to Early Kungurian (ca. 280 Ma), while cold and dry conditions prevailed during the mid–late Kungurian (ca. 277 Ma). The northern North China Craton, which supplied source material to the lower section of Zibo bauxitic clay, experienced rapid uplift and exhumation and underwent intense weathering under high humidity and warm temperatures during the late Artinskian to Early Kungurian. However, the source area shifted from the north to a more central region as the climate transitioned to cold and dry conditions in the mid–late Kungurian. Considering that detrital clay formation is indicative of specific climatic conditions, the Permian bauxitic clay deposits in Zibo provide a valuable record of environmental changes during the late Paleozoic ice age (LPIA; ca. 360–260 Ma).

Lower Permian (Late Kungurian) conodonts from the Sibumasu Terrane, Malaysia: paleoecological, paleobiogeographical and tectonic implications

AbstractLate Kungurian (Lower Permian) conodonts are described from the Kanthan Limestone, Perak, Peninsular Malaysia and for the first time from the Sibumasu Terrane of the Malay Peninsula. The co-occurrence of Gullodus duani, Gullodus hemicircularis, Gullodus sicilianus, Mesogondolella lamberti and Mesogondolella siciliensis represent the Mesogondolella lamberti International Conodont Zone and the broadly equivalent Mesogondolella siciliensis Regional Conodont Zone. A small fault-bounded basal Pennsylvanian (basal Bashkirian) conodont fauna including Gnathodus girtyi simplex and Declinognathodus inaequalis is also reported. The late Kungurian conodonts from the Kanthan Limestone were deposited in a relatively deep-water environment on the northern passive margin of the Sibumasu Terrane of the eastern Cimmerian Continent located at c. 35oS latitude. Biogeographically, the fauna represents the southern peri-Gondwana Cool Water Province which is consistent with its palaeogeographic location. A new scheme, utilizing characteristics of P1 elements, including position of the 1st denticle, location of 2nd and 3rd denticles, platform shape, platform cross-section, denticle shape in cross-section, and lateral denticle development is proposed for distinguishing between species of the hindeodid genera Gullodus, Hindeodus and Isarcicella. The late Kungurian fauna from the Kanthan Limestone represents the southern peri-Gondwana Cool Water Province supporting palaeogeographic reconstructions placing the Sibumasu Terrane in moderate southern palaeolatitudes in the Kungurian.

The Kalkowsky Project - Chapter IV. Case study of the Happy Spraberry oil reservoirs in NW Texas (with a micropaleontologic and biostratigraphic supplement): Collapsed molds should not be treated as a category of distorted ooids

The subsurface upper Spraberry Formation in NW Texas is dominantly composed of calcareous turbidites and debris-flows. The petrographic analysis of its porous grain-supported fabrics revealed the presence of controversial superimposed compaction fabrics, sometimes referred to as "distorted ooids". Based on the paragenetic sequence, it is demonstrated that these allochems were not distorted. In fact, the related zigzag and silcrow (§) patterns result from the collapse of molds, either oomolds or biomolds, in response to mechanical compaction of the fragile framework made up of isopachous Low-Mg Calcite cement surrounding these empty molds. As a side finding, this stratigraphic unit, which was said to be late Kungurian in age, is proved to be nearly 7 millions of year older.

A new late Kungurian (Cisuralian, Permian) conodont and fusuline fauna from the South Qiangtang Block in Tibet and their implications for correlation and paleobiogeography

A late Kungurian (Cisuralian, Permian) fauna including conodonts and fusulines is reported for the first time from the limestone units in the lower part of the Lugu Formation in the South Qiangtang Block (SQB) in Tibet. The conodonts include Mesogondolella siciliensis , M. qiangtangensis sp. nov., Sweetognathus subsymmetricus and S. guizhouensis . They all consistently indicate a late Kungurian age. The associated fusulines in the same interval include Armenina asiatica , Neoschwagerina simplex , Pseudodoliolina ozawai minima and Cancellina sp., which reliably indicate a Murgabian age. The coexistence of these conodonts and fusulines provides direct correlation between the base part of the Murgabian Stage in the fusuline-based Tethyan timescale and the late Kungurian Stage in the conodont-based international timescale. The conodont species S. subsymmetricus and S. guizhouensis together with the associated fusulines and brachiopods generally indicate a warm condition when the Lugu Formation was deposited, therefore, the SQB had incorporated into the equatorial warm water province during the late Kungurian. This contrasts with coeval cool water Vjalovognathus fauna from the basal part of the Xiala Formation in the Lhasa Block, the lower part of the Moulmein Limestone in the Hpa-An area in southern Myanmar and the Wandagee Formation in Western Australia. In addition, typical warm water Tethyan fusulines are absent in the Lhasa Block in the equivalent strata. These distinct faunal differences suggest that a wide Bangong-Nujiang Ocean between the SQB and the Lhasa Block probably existed during the late Kungurian. • A new late Kungurian conodont and fusuline fauna is reported from the South Qiangtang Block, Tibet. • The lower limestone units of the Lugu Formation are determined to be of late Kungurian in age. • The basal part of Murgabian Stage is correlative with the upper part of the Kungurian Stage. • The Bangong-Nujiang Ocean might have had a considerable width during the late Kungurian.

PERMIAN NON-MARINE BIVALVES FROM THE COLLIO AND GUNCINA FORMATIONS (SOUTHERN ALPS, ITALY): REVISED BIOSTRATIGRAPHY AND PALAEOBIOGEOGRAPHY

Non-marine bivalves are key fossils in Permian continental stratigraphy and palaeogeography. Although known since the end of 19th century, the occurrences from the continental basins of the Southern Alps have never been extensively studied. The non-marine bivalves from the Lower Permian Collio Formation (Brescian pre-Alps) are herein revised, and those from the Guncina Formation (Athesian District) are described for the first time. These two units yielded non-marine bivalves belonging to the genus Palaeomutela sensu lato, which is widespread in the Permian continental successions of eastern Euramerica. Three Palaeomutela morphotypes have been herein described: oval-subtriangular, subtrapezoidal and elongated. The latter includes several specimens herein assigned to Palaeomutela (Palaeanodonta) berrutii sp. nov. and dominates the Collio Formation association. The Guncina Formation yielded also the genus Redikorella, for the first time co-occurring on the same stratigraphic horizon of Palaeomutela, herein assigned to Palaeomutela (Palaeanodonta) guncinaensis sp. nov. To-date, it was generally accepted that the first members of the genera Palaeomutela and Redikorella occurred during the Ufimian (late Kungurian of the global scale) in the non-marine basins of the Cis-Ural Foredeep and of Angara, respectively. Such new finds in the early-middle Kungurian of southwestern Europe, well constrained by radioisotopic dating, suggest new global first appearance (First Appearance Datum) and a possible new center of origin of these genera. This fact raises new questions on biostratigraphy, palaeobiogeography and palaeoecology, which will require further research. If we assume that the genera Palaeomutela and Redikorella had only one center of origin, we need to hypothesise possible migration routes from SW Europe to the continental basins of Eastern Europe and Angara. Apparently, such migration could be better supported by a Pangaea B palaeogeographic configuration.

The age of North America’s youngest Paleozoic continental vertebrates: a review of data from the Middle Permian Pease River (Texas) and El Reno (Oklahoma) Groups

The youngest Paleozoic vertebrate-bearing continental deposits of North America are Middle Permian (Guadalupian) in age and occur in the Chickasha Formation (El Reno Group) of central Oklahoma and the lithostratigraphically lower San Angelo Formation (Pease River Group) of North-Central Texas. Although regarded originally as Guadalupian, these deposits have been assigned recently to the Early Permian on the basis of marine fossils and questionable lithostratigraphic correlations between marine and continental strata. A review of ammonoid genera recovered from the Blaine Formation, which overlies both the Chickasha and San Angelo in Oklahoma and Texas, shows that they range globally in age from the Early to Late Permian, but most occur in the Guadalupian or Middle Permian. A modest but intensively studied paleobotanical record of compression fossils from the San Angelo, as well as palynomorphs in rocks associated with the Chickasha, presents an unquestionably Middle to Late Permian flora dominated by voltzian conifers. The Chickasha and San Angelo vertebrate assemblages are overwhelmingly dominated by large caseid synapsids and indicate a biostratigraphic signal of early Guadalupian. The occurrence of the tupilakosaurid temnospondylSlaugenhopia, the parareptileMacroleter, and the eureptileRothianiscussuggests a Roadian age (lowermost Guadalupian) given the global records of closely related forms. These plant and vertebrate assemblages contrast sharply with those of underlying Cisuralian rocks of the Hennessey Formation of Oklahoma and the Clear Fork Formation of Texas, both of which are much more fossiliferous than those of the Guadalupian in the region. A barren interval of up to 300 m in thickness separates these fossil-bearing intervals. This true void in the late Kungurian was first reported a half century ago but has not been recognized in recent biochronology studies. Our findings, as well as those of other vertebrate paleontologists who have evaluated the San Angelo and Chickasha data by other means, strongly refute the current notion of “Olson’s Gap” as spanning most of the Roadian.

A late Cisuralian (early Permian) brachiopod fauna from the Taungnyo Group in the Zwekabin Range, eastern Myanmar and its biostratigraphic, paleobiogeographic, and tectonic implications

AbstractThe tectonic evolution of the Sibumasu Block during the Permian remains controversial, and Permian faunas and their paleobiogeographic affinities provide some insight into its paleogeographic and tectonic evolutionary histories. In this paper, a new brachiopod fauna dominated bySpinomartinia prolificaWaterhouse, 1981 is described from the uppermost part of the Taungnyo Group in the Zwekabin Range, eastern Myanmar. This brachiopod fauna includes 23 species and its age is well constrained as late Kungurian by the associated conodonts, i.e.,Vjalovognathus nicolliYuan et al., 2016 andMesogondolella idahoensis(Youngquist, Hawley, and Miller, 1951), contrary to the late Sakmarian age given to the same brachiopod faunas previously reported from southern Thailand and Malaysia. Based on comprehensive comparisons of the Cisuralian brachiopod faunas and other data in different parts of the Sibumasu Block, we consider that they are better subdivided into two independent stratigraphic assemblages, i.e., the lower (earlier)Bandoproductus monticulus-Spirelytha petaliformisAssemblage of a Sakmarian to probably early Artinskian age, and the upper (younger)Spinomartinia prolifica-Retimarginifera alataAssemblage of a late Kungurian age. The former assemblage is a typical cold-water fauna, mainly composed of Gondwanan-type genera, e.g.,BandoproductusJin and Sun, 1981,SpirelythaFredericks, 1924, andSulciplicaWaterhouse, 1968. The latter assemblage is strongly characterized by an admixture of both Cathaysian and Gondwanan elements, as well as some genera restricted to the Cimmerian continents. Notably, the spatial distribution pattern of these two separate brachiopod assemblages varies distinctly. The Sakmarian cold-water brachiopod faunas have been found in association with glacial-marine diamictites throughout the Sibumasu Block including both the Irrawaddy and Sibuma blocks. In contrast, the Kungurian biogeographically mixed brachiopod faunas are only recorded in the Irrawaddy Block, unlike the Sibuma Block that contains a contemporaneous paleotropical Tethyan fusuline fauna. Thus, it appears likely that by the end of Cisuralian (early Permian), the Sibumasu Block comprised the Irrawaddy Block in the south with cool climatic conditions, and the Sibuma Block in the north with a temperate to warm-water environment, separated by the incipient Thai-Myanmar Mesotethys.

Late Kungurian Conodonts of Pelagic Panthalassa from Seamount-Capping Limestone in Ogama, Kuzuu, Tochigi Prefecture, Japan

Biostratigraphy of conodonts is widely used for age assignment of Permian strata. In this paper, we report conodonts from the limestone of the Nabeyama Formation deposited on a pelagic seamount in Panthalassa, which is an oceanic realm where Permian conodont data are scarce compared to other oceanic realms. Samples collected from the lower part of the Nabeyama Formation yielded Mesogondolella idahoensis (Youngquist, Hawley and Miller) and Sweetognathus hanzhongensis (Wang), which indicate a late Kungurian age. Previous studies and fusulinids obtained in this study indicate that the studied samples belong to the Parafusulina yabei biozone. Therefore, the Parafusulina yabei Zone includes the uppermost Kungurian. Mesogondolella idahoensis and Sweetognathus hanzhongensis are respectively regarded as cool and warm water species. Hence, the distribution of cool and warm water conodont species may have overlapped in pelagic Panthalassa during the late Kungurian.

New Data on Cisuralian Ammonoids of Pay-Khoy (Russian Arctic) from the Family Paragastrioceratidae Ruzhencev, 1951

Recent finds of ammonoids from the Artinskian-Kungurian deposits of Pay-Khoy are reviewed. Based on these data, the phylogeny and systematics of the family Paragastrioceratidae are studied. It is concluded that at the beginning of the Kungurian a new genus Margoceras gen. nov. appeared and was a transitional link between the Sakmarian-Artinskian genus Paragastrioceras and the Late Kungurian Baraioceras. Three new paragastrioceratid species, Paragastrioceras cantabrignianum sp. nov., Tumaroceras paveli sp. nov. and Margoceras boreale gen. et sp. nov., are described

New conodont data related to the western Ouachita-Marathon-Sonora orogen: Age of the autochthonous Laurentian deformation

We report herein new Permian conodont data from the strata of the La Cueva Limestone and the Mina Mexico Formation in central Sonora. These data allow us to characterize the biostratigraphy of the southwestern Laurentian Permian successions and the last stage of the Ouachita-Marathon-Sonora orogen in northwestern Mexico. We studied three sections in central Sonora, which cover the stratigraphic contact between both formations. In the Las Rastras Section (LRS), we recognized a conodont association that includes Neostreptognathodus exsculptus sensu Henderson and McGugan, Sweetognathus “whitei”, Sw. subsymmetricus, and Hindeodus aff. H. minutus at its base and Sw. subsymmetricus, Hindeodus aff. H. gulloides, Gullodus tieqiaoensis, and Mesogondolella siciliensis at its top. These conodonts date the upper part of the La Cueva Limestone as latest early to earliest late Kungurian and the lower part of the Mina Mexico Formation as late Kungurian in the LRS. In the Sierra Martinez 1 and 2 sections (SMS-1 and SMS-2), located 7 km to the east of the LRS, the conodont association points to an age corresponding to the latest early to earliest middle Kungurian for both La Cueva Limestone and Mina Mexico Formation. This association is represented by the species Ns. exsculptus sensu Henderson and McGugan and Sw. subsymmetricus. The stratigraphic contact between both formations has been interpreted as the beginning of the autochthonous deformation of the Laurentian platform. This new conodont data allows us to associate this event to the latest early–earliest middle Kungurian in SMS-1 and SMS-2, and to the late Kungurian in the LRS showing a diachrony between these localities. This diachrony may be related to the continental oblique collision of Laurentia against Gondwana that resulted in progressively younger basins westward along the Ouachita-Marathon-Sonora orogen. This diachrony can also be due to the configuration of the subsiding Mina México foredeep, which would have produced a non-coeval contact in the areas closer to the thrust front and those located far from it.

First records of Early Permian conodonts from eastern Myanmar and implications of paleobiogeographic links to the Lhasa Block and northwestern Australia

An Early Permian (Cisuralian) conodont fauna is reported for the first time from the Sibumasu Terrane in eastern Myanmar. The conodont fauna includes Vjalovognathus nicolli and typical Mesogondolella idahoensis; some M. idahoensis possess transitional characters with M. lamberti and M. siciliensis. This fauna indicates a late Kungurian age. The longest range of the Taungnyo Group was from late Tournaisian to late Kungurian, and the range of the overlying Moulmein Limestone might be from late Kungurian through Guadalupian (Middle Permian). The nearly synchronous occurrence of identical conodont faunas from eastern Myanmar, the Lhasa Block and northwestern Australia provides important evidence that these tectonic units had a close paleogeographic, paleobiogeographic and paleoclimatic evolution during the late Cisuralian. The occurrence of this conodont fauna across the continuous boundary interval between the Taungnyo Group and Moulmein Limestone might indicate a paleoclimatic transition from Early Permian cool-water conditions to a Middle to Late Permian warm-water setting due to tectonic drifting of the relevant blocks and/or paleoclimatic amelioration after the Late Paleozoic Ice Age (LPIA) from Carboniferous to Cisuralian. This discovery also suggests that the terranes in eastern Myanmar are complicated by subsequent tectonic mergence and possibly of multiple origins based on the conodont and fusuline faunal affinities in different areas of eastern Myanmar.

Permian Nonmarine Bivalve Mollusks: Review of Geographical and Stratigraphic Distribution

Data on global geographical and stratigraphic distribution of Permian nonmarine bivalves, which have not included in generalizing works are considered. The continental Permian beds of Euramerican, Angarian, Cathaysian, and Gondwanan paleozoogeographic realms are compared with reference to the nonmarine bivalve fauna from the Late Kungurian to Permian–Triassic boundary. It is concluded that the family Palaeomutelidae Lahusen, 1897 and also the genera Anadontella Betekhtina, 1987, Prilukiella Plotnikov, 1945, and Concinella Pogorevitsch in Betekhtina, 1966 are of the greatest significance for correlation of particular sections.

Global Permian brachiopod biostratigraphy: an overview

Abstract Establishing a Permian brachiopod biochronological scheme for global correlation is difficult because of strong provincialism during the Permian. In this paper, a brief overview of brachiopod successions in five major palaeobiogeographical realms/zones is provided. For Gondwanaland and peri-Gondwanan regions including Cimmerian blocks, Bandoproductus and Punctocyrtella (or Cyrtella ) are characteristic of the lower Cisuralian, as is Cimmeriella for the middle Cisuralian. As the Cimmerian blocks continued drifting north during the late Kungurian, accompanied by climate amelioration, contemporaneous brachiopods inhabiting these blocks showed a distinct shift from cold-water to mixed or warm-water affinities. However, coeval brachiopods in the Northern Transitional Zone (NTZ) are characterized by warm-water faunas and are associated with fusulinids in the lower Cisuralian. The Guadalupian brachiopods of the NTZ were clearly mixed between the Boreal and palaeoequatorial affinities. The end-Guadalupian is marked by the disappearance of a few characteristic genera, such as Vediproductus , Neoplicatifera and Urushtenoidea , in the Palaeotethyan region. The onset of the end-Permian mass extinction in the latest Changhsingian is clearly exhibited by the occurrence of the dwarfed and thin-shelled brachiopods commonly containing Paracrurithyris .

Prevailing anoxia in the Kungurian (Permian) of South China: Possible response to divergent climate trends between the tropics and Gondwana

The Kungurian ocean-climate system has received little attention, but a new compilation of geochemical and paleoclimatic proxies suggest more complex climate dynamics during the Late Paleozoic icehouse–greenhouse transition than previously considered. Here, integrated carbon isotope stratigraphical, sedimentological, and geochemical data across two Early–Middle Permian successions in the Youjiang Basin, South China, is presented. These proxies indicate widespread anoxia below or near the water-sediment interface in South China during the Kungurian. High primary productivity, high sedimentation rate, and a relative sea-level rise are here proposed as being responsible for this process in the late Kungurian, but cannot account for the remaining anoxia at cycle boundaries. We put forward a hypothesis that divergent climate trends between the tropics and Gondwana might have played an important role in ocean stagnation and prevailing O2-deficient conditions in and probably outside South China during the Kungurian. The termination of anoxia in this region during the latest Kungurian is attributed to an intensification of oceanic circulation, a rise in atmospheric pO2 concentrations, a sea-level drop, depressed primary productivity, and low sedimentation rates. This study calls for further high-resolution sedimentological and geochemical investigations on the paleotropics outside South China, in order to elucidate the icehouse-greenhouse transition at the global scale.

New occurrences of tetrapod ichnotaxa from the Permian Orobic Basin (Northern Italy) and critical discussion of the age of the ichnoassociation

AbstractThe late Cisuralian (Artinskian–Kungurian) is a key time interval for Permian tetrapod evolution. In all the main low‐latitude Pangean sites, the fossil footprint record clearly shows a diversification and dispersal of non‐synapsid amniote tracks compared to the early Cisuralian (Asselian–Sakmarian). However, data on latest Cisuralian (i.e. late Kungurian) sites are quite fragmentary. A new ichnotaxonomic study was carried out in the central part of the Orobic Basin, where the highly‐fossiliferous Pizzo del Diavolo formation crops out and can potentially cover this gap in knowledge. The following tetrapod ichnogenera were identified: Amphisauropus, Batrachichnus, cf. Dimetropus, Dromopus, Erpetopus, Hyloidichnus, Limnopus, cf. Merifontichnus and Varanopus; they can be attributed to seymouriamorph and temnospondyl amphibians; pelycosaur synapsids; and diapsid, parareptile and captorhinid reptiles. Dimetropus and Merifontichnus are identified for the first time in the Permian of Italy. The ichnoassociation, in agreement with the radiometric dating of the underlying Cabianca formation, suggests a late Kungurian (latest Cisuralian) age for the Pizzo del Diavolo formation. It includes the youngest and most diverse non‐synapsid amniote ichnofauna of the Cisuralian with five different ichnogenera and possibly six ichnospecies, and thus constitutes a key area for the study of eureptile and parareptile dispersal at low latitudes of Pangaea in the time span that immediately pre‐dates the first therapsid synapsid radiation.

Early Permian conodonts from the Xainza area, central Lhasa Block, Tibet, and their palaeobiogeographical and palaeoclimatic implications

The Tibetan Plateau, the highest plateau in the world, is relatively difficult to access. Therefore, the stratigraphy and fossils in this area are poorly known, although they are very important for interpreting the palaeogeographical evolution of different tectonic blocks. Here we report the new discovery of an abundant conodont fauna from the lowest part of the Xiala Formation in the central part of the Lhasa Block, Tibet. This conodont fauna includes three genera and four species (Mesogondolella idahoensis, M. siciliensis, Vjalovognathus nicolli Yuan, Shen & Henderson sp. nov. and Hindeodus sp.). The conodont fauna indicates that the lowest part of the Xiala Formation is late Kungurian in age based on the presence of abundant Mesogondolella idahoensis and the denticle characters of Vjalovognathus nicolli sp. nov. The presence of the conodont genus Vjalovognathus, the associated small solitary corals and the absence of any fusulinids clearly suggest a cool-water condition in the lower part of the Xiala Formation. Thus, the Xiala Formation in the central Lhasa Block can be restricted to an age from late Kungurian to Wuchiapingian. This is in contrast to the warm-water faunas consisting of abundant fusulinids, compound and large solitary corals, and warm-water conodonts in the upper part of the Xiala Formation from late Guadalupian to Wuchiapingian in age. This dramatic faunal change suggests that either the palaeoclimate had greatly changed from a cold condition to a warm condition after the late Kungurian in the peri-Gondwanan region, or the palaeogeographical position of the Lhasa Block had drifted northward into the warm-water regime from the late Kungurian to Guadalupian. The new family Vjalovognathidae Shen, Yuan & Henderson fam. nov. and the new species Vjalovognathus nicolli Yuan, Shen & Henderson sp. nov. are proposed, based on abundant specimens from central Tibet.http://zoobank.org/urn:lsid:zoobank.org:pub:35EFEF79-315E-4CCE-A72E-5BE27CFAFBF5

Discovery of the Misellina Zone (latest Kungurian) in the Lentas unit of the Pindos Series (Crete)

The origin and significance of the Lentas unit in southern Crete (Greece) is still subject to controversies. New stratigraphical and palaeontological results allow correlations with the classical Pindos-type series in Greece. In particular, new datings from reworked fossiliferous limestone pebbles within the Lentas unit are presented. These data concern especially the carbonate microfacies and carbonate microfossils from the latest Early Permian (i.e., from the late Kungurian Substage or Misellina Zone). For the first time in Greece, this period is recognized as being rich in foraminifers and calcareous algae. These fossils are described; especially, two dasycladales Likanella (?) cretae nov. sp. and Uragiellopsis bonneauii nov. sp. are established. The presence of these reworked Palaeotethyan sediments at the base of the Lentas unit suggests a derivation from the Palaeotethyan active margin (arc/fore-arc series).