Thecamoebians from Late Permian Gondwana sediments of peninsular India

The evolutionary history of thecamoebians (testate amoebae) extends back to the Neoproterozoic Era. However, until now, these have had a restricted, discontinuous and modest record across the world. The studied sediment of Raniganj Formation (Godavari Graben), Andhra Pradesh, India has been assigned as Late Permian on the basis of co-occurring age-diagnostic Late Permian palynomorphs. About sixteen thecamoebian species and one taxon incertae sedis have been recorded here in the palynological slides on the basis of shell morphology and morphometry. Out of these, five belong to the family Arcellidae, seven to Centropyxidae, two to Trigonopyxidae, one to Difflugiidae, one to Plagiopyxidae, and one is regarded incertae sedis. The morphometric characteristics of fossil forms resemble their corresponding extant species studied from ecologically diverse fresh water wetlands in India. In general, the ratio of shell diameter and aperture diameter of Late Permian fossil and extant specimens show significant correlation in all the studied species. Except that, the ratio of shell length and breadth is the distinguishing feature between Centropyxis aerophila and C. aerophila ‘sylvatica’, rather than the ratio of shell length and longest diameter of the shell aperture in both fossil and extant forms. The study elucidates the minimal morphological evolution in thecamoebians and their survival during mass extinction periods and stressful environmental conditions over the geological timescale.     

Lower Permian bivalves from central Patagonia, Argentina

The earliest Permian faunal successions of central Patagonia show compositional changes that probably reflected the environmental warming at the end of the Gondwana glaciations. Bivalves of Asselian to probably Early Tastubian age are described. A new genus,Sueroa, is proposed to reunite a previously known species and a new species,Sueroa andreisi n. sp. Another five new species:Parallelodon? quichaurensis n. sp.,Heteropecten cortignasi n. sp.,Etheripecten saraviae n. sp.,Streblopteria montgomeryi n. sp. andPraeundulomya moreli n. sp. are described. Two previously known species:Malimania patagoniensis (González) andEuchondria sabattiniae González are revised and new occurrences are reported. A further eleven species are described, but they are left in open nomenclature being because they are insufficiently known; these are:Phestia? n. sp.,Modiolus sp.,Palaeoneilo sp.,Stutchburia sp.,Schizodus sp.,Vacunella? sp.,Edmondia sp.,Myonia? n. sp.,Myonia? sp. andPachymyonia? n. sp.     

Late Paleozoic stromatolites: new insights from the Lower Permian of Kansas

Carboniferous to Permian marine stromatolites are widely dispersed across the Pangaean margins and embayments and are typified by the ‘Ottonosia-grade stromatolite’ (designated herein). This stromatolite type consists of a well-laminated oncoid or domical stromatoid that developed into branching, laminated columns in the upper reaches. To develop a model for the global pattern, we investigated Lower Permian stromatolites from Kansas (Howe Limestone Member, Red Eagle Limestone). Stromatoids from the Lyon County locality typify the Ottonosia-grade stromatolites. The laminae are sharp throughout the stromatoid and are defined by an increase in cornuspirid foraminfera and algal filaments. The upper zone of the stromatoid is composed of well-laminated branching and brecciated columns (‘pseudo-thrombolitic’). Coeval stromatolites from a new exposure at the Tuttle Creek Dam spillway possess a more massive mesostructure. These stromatolites are composed of a turbinate stromatoid or oncoid base and an overlying domical stromatoid, and are rimmed by smaller meandering columns. Only the basal stromatoid, oncoids, and upper columns are well laminated. In both localities, the microbial-constructing ecosystem is dominated by cornuspirids and calcifying filamentous algae (?Girvanella). The mesostructural differences of the stromatolites are due to different environments of formation. The Tuttle Creek stromatolites formed in a shallow-subtidal to intertidal open marine setting. The coeval Lyon County stromatolites formed in a semi-restricted, marginal marine environment such as a lagoon or supratidal zone. Based on this information and independent sedimentological data, we conclude that lagoonal or supratidal zones were common features in the late Paleozoic intracratonal zones of the Pangaean supercontinent and account for Ottonosia-grade stromatolites occurring in the Laurentian mid-continent, the Zechstein Basin, Japan, Brazil, and Tunisia.     

Faunal migration into the Late Permian Zechstein Basin - Evidence from bryozoan palaeobiogeography

Late Permian bryozoans from the Wegener Halvø, Ravnefjeld and Schuchert Formations in East Greenland have been investigated. 14 genera are recognised.Integration of the new bryozoan data from the Upper Permian of East Greenland with data on the distribution of Permian bryozoans along the northern margin of Pangea is used to test hypotheses concerning Late Palaeozoic evolution of the North Atlantic region. During the Permian, the Atlantic rift system formed a seaway between Norway and Greenland from the boreal Barents Shelf to the warm and arid Zechstein Basin. This seaway is considered to be the only marine connection to the Zechstein Basin and therefore the only possible migration route for bryozoans to enter the basin. The distribution of Permian bryozoans is largely in keeping with such a connection from the cool Barents Shelf past the East Greenland Basin to the warm Zechstein Basin and also corroborates the change in temperature through this connection.     

Palaeoenvironmental changes recorded in the palynology and palynofacies of a Late Permian Marker Mudstone (Galilee Basin,Australia)

Reconstructing the terrestrial palaeoenvironment during the end-Permian is made challenging by widespread erosion and ecosystem destruction. High-resolution sampling for palynofacies and palynology in sections that preserve the boundary interval allows for detailed examination of the drastic environmental changes that characterize the Permian–Triassic mass extinction. In the Bowen and Galilee basins in eastern Australia, this environmental perturbation is recorded within a Marker Mudstone that occurs above the uppermost Permian coal seams. The Marker Mudstone is used as a stratigraphic reference level at many localities, but has previously only been studied at a single locality in the Bowen Basin. In the present study, borehole Tambo 1-1A drilled in the Galilee Basin was selected to clarify whether this black, organic-rich mudstone marks a marine transgression, and to examine potential indicators of the end-Permian mass extinction. A total of 22 samples were taken from the mudstone unit, and from the over- and underlying strata and processed for palynology, palynofacies, and carbon isotope analysis.Biostratigraphic data indicate that the Marker Mudstone itself covers the uppermost part of unit APP5, with the first index taxa of unit APP6 floras occurring in samples less than 80 cm above this interval. This can be correlated with several other localities in the Bowen and Sydney basins where this shift occurs just above the uppermost Permian coal seam. Palynofacies data agree with previous interpretations of a southwards prograding delta that subsides as base level rises to form an extensive waterbody in which the Marker Mudstone was deposited. A change from translucent phytoclast-dominated to opaque phytoclast-dominated palynofacies within the Marker Mudstone suggests a shift to more oxic conditions in the water column, while base level begins to fluctuate, or increased terrestrial input from fluvial systems as the hinterland rises. Algal bodies resembling Botryococcus are found in the strata above the Marker Mudstone, but differ in morphology from the algal bodies found in the deltaic facies below. The presence of acanthomorph acritarchs in the Marker Mudstone and in the overlying Rewan Formation may indicate marine influence. Forms resembling fungal spores are present, but they do not show a “spike” as seen in other P–T boundary localities.The relative position of unit APP6 to the P–T boundary itself remains unclear. APP6 assemblages are dominated by simple acavate trilete and cavate trilete spores, which suggests stressed environment dominated by ferns and lycopods. The presence of degraded phytoclasts towards the top of the Marker Mudstone may also be used to suggest a mass-extinction interval. They may also be indicative of shifting local palaeoenvironmental changes, an interpretation that is supported by the low magnitude negative excursion of the δ¹³C isotope values within the Marker Mudstone. More datasets from the Bowen and Galilee basins will be essential to decoupling these signals.     

An Odontogriphid from the Upper Permian of Australia

A problematic organism, Bowengriphus perphlegis gen. et sp. nov., is described based on two specimens from the Late Permian Rangal Coal Measures of eastern central Queensland. It displays a double-looped feeding apparatus bearing small conical elements, considered homologous with that of the supposed lophophorate Odontogriphus omalus Conway Morris, 1976, from the Middle Cambrian Burgess Shale of British Columbia, Canada. Odontogriphids are thus interpreted as a group that survived through the Palaeozoic and made the transition from marine to freshwater environments. Recent proposals that odontogriphids are stem-group chordates are not well established.     

Evolution of the glossopterid gymnosperms from Permian Gondwana

Our understanding of the glossopterid gymnosperms from the Permian of Gondwana has recently been greatly enhanced through the study of anatomically preserved plant remains in cherts from several localities in Australia and Antarctica. Studies ofGlossopteris leaves, leaf-stem attachment, stem structure and wood anatomy,Vertebraria roots, ovule- and pollen-bearing reproductive structures and putative glossopterid pollen and ovules demonstrate that the glossopterids were a diverse group of sophisticated gymnosperms. Comparative studies of different Permian chert floras show that while some glossopterid elements are widespread, other taxa appear to be more localized in their distribution. As information from petrified plant-bearing cherts becomes available, it can be used to reconstruct whole glossopterid plants and establish their paleogeographic distribution.     

Early Permian brachiopod faunas from Peninsular India: Their Gondwanan relationships

The Early Permian (Late Asselian? to Aktastinian?) brachiopod faunas of Peninsular India are revised in terms of current taxonomy. Genera such as Semilingula, Arctitreta, Etherilosia, Strophalosia, Aulosteges, Bandoproductus, Cyrtella, Neospirifer, Crassispirifer, Tomiopsis and Gilledia confirm the Gondwanan aspect of the faunas and a close relationship, at the generic level, to the Early Permian brachiopod faunas of Western Australia. Peninsular Indian Early Permian brachiopod faunas belong to a complex of Gondwanan and peri‐Gondwanan faunas from Oman and the Pamirs in the West to Australasia in the east. This distribution implies relative freedom of migration for the faunas along the northern margin of Gondwana during the Early Permian.     

福建漳平下二叠统的小有孔虫

福建漳平岭兜下二叠统地层发育良好,序列清楚,与ting类共生的小有孔虫化石丰富。根据化石群垂直分布特点,可分为三个小有孔虫组合,自下而上为Geintzina-Pachyphloia组合,Langella-Pseudoglandulina longa组合及Hemigordius qinglongensis-Cribrogenerina celebrata组合。这三个小有孔虫组合在福建均属首次发现。这发现为下二叠统的地层时代归属又提供一佐证。     

Early Permian radiolarians from Southern Thailand,the deglaciation of Gondwana and the age of the basal Ratburi Group

The first radiolarian fauna obtained from Permian carbonates in Thailand is of late Kungurian age and is present in the basal beds of the carbonate–mudstone–chert Phap Pha Formation, Ratburi Group. This succession contains several species of the radiolarian Pseudoalbaillella, and some sponge spicules. The radiolarian fauna consists of abundant Pseudoalbaillella aidensis and P. elegans together with P. fusiformis, P. longtanensis, P. m. rhombothoracata and P. sp. A. Other species include P. cf. aidensis, P. cf. elongata, P. cf. fusiformis, P. cf. ishigai, P. cf. lomentaria, P. cf. longicornis, P. cf. longtanensis, P. cf. ornata, P. cf. simplex, P. cf. m. scalprata, P. cf. m. postscalprata, P. cf. u–forma m. I, P. cf. u–forma m. II, and P. spp. The radiolarian assemblage suggests its correlation to the P. longtanensis Zone which, in turn, is correlated to the P. ishigai Zone of late Kungurian age. The occurrence of an abundant but generically low–diversity radiolarian fauna suggests restricted physical conditions and, with other evidence, suggests deposition along a cool deglaciating or deglaciated continental margin with an abundance of silica possibly provided by glacial meltwaters. The abundant chert in the Phap Pha Formation is part of the widespread Permian Chert Event.     

内蒙古乌达地区早二叠世晋囊蕨属一新种

通过扫描电镜研究,建立了内蒙古中部乌达地区下二叠统山西组晋囊蕨诉一个新种Ｃｈａｎｓｉｔｈｅｃａ ｗｕｄａｅｎｓｉｓ ｓｐ ．ｏｎｖ．。新种的小心片Ｓｐｈｅｎｏｐｔｅｒｉｓ型,囊群椭圆形,由４～１０个孢子囊组成,着生一示羽片背面,位于中脉的两侧。环带横列于孢子囊的上部,完全,单排细胞,细胞数目约为１８个,这些特征表明新种属于里白科。     

Late Permian Discordichthyiformes (Osteichthyes) from European Russia

New Late Permian fishes combining features characteristic of several classes are analyzed and redescribed. They were assigned to the family Discordichthyidae of the order Discordichthyiformes comprising three genera and four species: Mutovinia stella Minich, Geryonichthys longus A. Minich, G. burchardi A. Minich, and Discordichthys spinifer A. Minich (Minikh, 1998). A new species, Mutovinia sennikovi sp. nov., is described. Due to rapid evolutionary replacement, discordichthyids are rather useful stratigraphically. The photographs of the skeleton and membrane bones of these fishes are published for the first time.     

A second varanopseid skull from the Upper Permian of South Africa: implications for Late Permian 'pelycosaur' evolution

Late Permian terrestrial faunas of South Africa and Russia are dominated taxonomically and ecologically by therapsid synapsids. On the basis of a single specimen from the Upper Permian of South Africa, the varanopseid Elliotsmithia longiceps is the sole basal synapsid ('pelycosaur') known from Gondwana. Recent fieldwork in the Upper Permian of South Africa has produced a second varanopseid specimen that is referrable to Elliotsmithia . Data from both this specimen and the holotype suggest that Elliotsmithia forms a clade with Mycterosaurus from the Lower Permian of North America and Mesenosaurus from the Upper Permian of Eastern Europe. That postulate is supported by the three most parsimonious trees discovered in a new analysis of varanopseid phylogeny. However, the available data cannot resolve the interrelationships of these three genera. The new phylogenetic results contrast with earlier work identifying Elliotsmithia as the basal member of a clade that includes the North American taxa Aerosaurus , Varanops , and Varanodon . The new trees reduce the stratigraphic debt required by the latter scenario, and the one with the least stratigraphic debt identifies Elliotsmithia and Mesenosaurus as sister taxa. Two new taxa are erected, Mycterosaurinae and Varanodontinae, for the two varanopseid subclades.     

新疆吐鲁番盆地桃树园晚二叠世非海相腹足类

提要新疆吐鲁番盆地桃树园地区晚二叠世地层称作下仓房沟群,自下而上分为泉子街组、梧桐沟组和锅底坑组,为河–湖相碎屑沉积,剖面连续,层序清楚,动、植物化石丰富。文中研究的腹足类标本产于桃东沟剖面梧桐沟组下部和中部的介壳灰岩层和灰岩透镜体中,见有2层,计有2科4属6种:Xinjiangospira rotundata Yu et Zhu,Xinjiangospira habita sp.nov.、Hydrobia turpanensis Wei、Hydrobia orientalis sp.nov.、Pseudamnicola taodonggouensis sp.nov.和Valvata complanusa sp.nov.;与腹足类共生的有双壳类、叶肢介、介形类,以及植物和脊椎动物化石等,其中双壳类主要是Palaeanodonta,Palaeomutela和Anthraconauta等属。该腹足动物群由Hydrobiidae和Valvatidae的属种组成,标本数量多,壳体小,保存完好,是迄今已知属种最丰富的古生代淡水腹足类动物群。当前梧桐沟组腹足动物群面貌与准噶尔盆地大龙口剖面小龙口组...     

New seeds of gymnosperms from the Lower Permian of the Ural mountains

New taxa of detached seeds are described from the Kungurian (Lower Permian) of the Middle Cis-Urals: Laevigatospermum compressum gen. et sp. nov., Hirsutospermum paniculatum gen. et sp. nov., Rugosospermum callosum gen. et sp. nov., and Craspedosperma filiferum sp. nov. The systematic position of the new taxa is discussed.     

Amphibian swimming traces from the Lower Permian of southern New Mexico

Fossilised traces of swimming amphibians, assigned to Batrachichnus delicatulus and Serpentichnus robledoensis igen. et isp. nov., are described from the Lower Permian of the Robledo Mountains, southern New Mexico. The B. delicatulus specimen is interpreted as a trackway of a small 'amphibian' (temnospondyl, nectridean, microsaur or juvenile embolomere) swimming straight ahead. S. robledoensis consists of repeated pes imprints separated by discontinuous, L-shaped imprints (body traces). It is interpreted as a trackway of an 'amphibian' swimming in a similar manner to the motion of a side-winding snake. The producer of S. robledoensis is more distinctive than in B. delicatulus , and is suggestive of the lysorophian Brachydectes . This is the first locomotory trace to be assigned to this 'amphibian' group.     

An Early Jurassic flora from the Clarence-Moreton Basin, Australia

A low-diversity Early Jurassic flora preserved in floodbasin siltstones of the Marburg Subgroup at Inverleigh Quarry in the Clarence-Moreton Basin, eastern Australia, is dominated by Allocladus helgei Jansson sp. nov., a conifer with denticulate leaves tentatively attributed to Araucariaceae. The assemblage also includes Rintoulia variabilis and Caytoniales, (Caytonia cucullata McLoughlin sp. nov. and cf. Sagenopteris nilssoniana), reinforcing the wide distribution of this order in Early to Middle Jurassic floras of Gondwana. Ferns (Cladophlebis and Sphenopteris species) and isoetalean lycophytes (Isoetites sp.) constitute the herbaceous elements of the flora. The palynoflora is dominated by cheirolepidiacean (Classopollis) pollen and is attributable to the upper part of the Corollina (= Classopollis) torosa Zone of late Pliensbachian–early Toarcian age (180–185 Ma). The Inverleigh flora represents one of the few Australian assemblages dated between the major phases of floristic turnover at the end of the Triassic and the Toarcian. Sedimentological characteristics, cuticular features of the conifer leaves and the abundance of free-sporing plants indicate a relatively humid palaeoclimate for the Clarence-Moreton Basin Early Jurassic.     

内蒙古乌达地区早二叠世晋囊蕨属一新种

Chansitheca (Sphenopteris) wudaensis sp. nov. is described based on the materials collected from the Lower Permian Shansi Formation of Wuda, Nei Mongol, China. The frond is small and at least two times pinnate. The pinnule is sphenopteroid. The sori are borne on the abaxial surface of the pinnule, arranged in two rows parallel to the midvein, elliptic,and composed of 4-10 round sporangia. The indusium is absent. The annulus is transverse and complete, and consists of about 18 thickened cells. The features of the fertile parts, sori, sporangia and annulus and the absence of indusium indicate that the new species belongs to the Gleicheniaceae.     

Late Carboniferous-Early Permian Tetrapod Ichnofauna from the Khenifra Basin, Central Morocco

In terms of cumulative thickness and areal extent, the Khenifra Basin is one of the most important outcrops of Late Palaeozoic red-beds in central Morocco. Macro- and microfloral remains near the centre of the 1800 m-thick succession of interbedded conglomerates, sandstones, and mudstones are considered to be of middle to late Early Permian age. Here we give the first comprehensive analysis of the vertebrate ichnofossil record from the study area, based on 17 specimens of isolated footprints and incomplete step cycles collected at three localities that are lithostratigraphically equivalent to the plant-bearing horizons. The tetrapod ichnofauna comprises tracks of the plexus Batrachichnus Woodworth - Limnopus Marsh, Ichniotherium sphaerodactylum (Pabst), Dimetropus Romer and Price, and Dromopus Marsh which can be referred to temnospondyl, diadectomorph, synapsid (“pelycosaurian”) and early sauropsid trackmakers. This clearly Euramerican footprint assemblage, including the first occurrences of Ichniotherium and Dimetropus from outside Europe and North America, indicates a Late Carboniferous to Early Permian age of the fossiliferous strata. Judging from the relatively diverse ichnofauna and flora, the Khenifra Basin must have represented a well-established terrestrial ecosystem during that period. Its habitat could be specially important for the understanding of the phylogeny and dispersal of early tetrapods, inasmuch as we are able to report on an extremely rare type of diadectomorph footprint hitherto known only from the Early Permian of central Germany.     

A gorgonopsian from the Wutonggou Formation (Changhsingian,Permian) of Turpan Basin,Xinjiang, China

Gorgonopsians were widely distributed during the Permian, and went extinct by the end of Permian. However, their fossil localities in the North Hemisphere are concentrated in the eastern European portion of Russia, except for one possible canine from the North China. A specimen from the Wutonggou Formation of Turpan Basin, Xinjiang, China, dated ～253.3 Ma, is identified as a gorgonopsian based on dental features. This discovery shows that the gorgonopsians survived in northern warm temperate zone about ～253.3 Ma, contemporaneous with the latest records of Russia and South Africa. This specimen may represent one of the latest records of gorgonopsians.