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1.
The skull of a small anomodont therapsid, from the Tapinocephalus Assemblage Zone (Abrahamskraal Formation, Beaufort Group, Upper Permian) in Northern Cape Province, South Africa, represents a new basal dicynodont and is described in detail. Colobodectes cluveri gen. et sp. nov. is distinguished from other dicynodonts by an anteroposteriorly extensive caniniform process, parietals that were broadly overlapped posterolaterally by posterodorsal processes of the postorbitals, diverging anterior palatal ridges, and a dorsoventrally low foramen magnum. A phylogenetic analysis indicates that Colobodectes is the basalmost member of a dicynodont clade that excludes Eodicynodon . This position is not particularly strong, as two additional steps are needed to make Colobodectes and Eodicynodon oosthuizeni exchange places on the most parsimonious tree. Another discovery of the phylogenetic analysis is that there is little basis for recognizing Eodicynodon oelofseni as the closest relative of E. oosthuizeni . The former species is identified as the sister taxon of a clade that includes the latter and all other dicynodonts.  相似文献   

2.
A new actinopterygian fish Yaomoshania minutosquama gen. & sp. nov., from the Upper Permian of the Dzungaria [Junggar] Basin in China is described. The material consists of two very fragmentary specimens showing almost exclusively scale rows. The arrangement of the scale rows of the holotype resembles the reversion lines of acanthodian caudal fins and of cheirolepids. The size and shape of the scales, and the diminishing size of the scales along the rows, is similar to those of acanthodians and those actinopterygians with small scales such as Cheirolepis. However, the histology of the scales demonstrates features that are found in more advanced actinopterygians: superimposed ganoine lamellae, the arrangement of dentine tubules and pulp canals, buried odontodes stacked on each other to make the ornamental ridges, and an asymmetric pattern of growth achieved by extensive remodelling (resorption and redeposition) of all layers of the scale. Yaomoshania minutosquama is proposed as a small-scale bearing, basal actinopterygian, different from Cheirolepis , but characterized by advanced histological characters.  相似文献   

3.
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.  相似文献   

4.
Exceptionally well-preserved specimens of Mizzia yabei (Karpinsky) were discovered in bituminous packstone intercalations of the early Upper Permian Maokou Formation of Anxian County (Sichuan, China). Staining techniques and x-ray diffraction reveal that the organic encrustation around the central stem and the lateral branches consists of aragonite. Average aragonite contents range between 27% and 40%. The bulk of the remaining 60–73% calcite represents cement. The total Sr-content is 3, 400 ppm, indicating 8,000–10,000 ppm for the aragonite fraction. The organically precipitated aragonite was deposited as closely packed fibres, 10–20 μm long and 0.5–1 μm wide. The fibres are arranged in clinogonal (water-jet) fascicles, which diverge towards the central (spar-filled) stem. This microstructure shows that the mineralization of the mucilage started at the periphery of the extracellular encrustation and progressed toward its interior. Diagenetic alterations of the original aragonite include various stages of breakdown of the fibres into 0.5–1 μm large granules (micritization), minor syntaxial growth of the fibres and local transformation of acicular aragonite into neomorphic calcite. The dasycladaleans from the Permian of Sichuan appear to be by far the oldest representatives of this order with preserved aragonitic mineralogy and microstructure. Comparably well-preserved examples are only known from Eocene and younger deposits.  相似文献   

5.
A New Basal Lystrosaurid Dicynodont from the Upper Permian of South Africa   总被引:1,自引:0,他引:1  
A new genus and species of late Permian dicynodont, Kwazulusaurus shakai , is described on the basis of a complete skull from the late Permian Dicynodon Assemblage Zone of the South African Beaufort Group. It is an advanced form which shows characters, such as the shape of the snout and the loss of the ectopterygoid, that link it to the early Triassic genus Lystrosaurus. Kwazulusaurus represents the most basal member of the lystrosaurian lineage. The phylogeny of progressive pristerodontian dicynodonts is discussed. It appears possible that the Kannemeyeriiformes and Lystrosauridae do not form a monophylum, as previously assumed. Instead a sister-group relationship between lystrosaurids and dicynodontids plus kannemeyeriiforms is suggested.  相似文献   

6.
The gliding reptiles of the Upper Permian   总被引:1,自引:0,他引:1  
The skeleton of a long-ribbed reptile from the Upper Permian Marl Slate of north-east England is described. The animal is assigned to the genus Weigeltisaurus , previously recorded from the Kupferschiefer of West Germany. Long-ribbed reptiles from the Upper Permian of Madagascar are also considered. Daedalosaurus Carroll, 1978 is a junior synonym of Coelurosauravus Piveteau, 1926. The European and Madagascan genera can be accommodated within a single family Coelurosauravidae, Infraclass Eosuchia. The skull is diapsid with an incomplete lower temporal arcade. Comparison with the modern Draco and the Upper Triassic kuehneosaurids supports the conclusion that the coelurosauravids were effective gliders.  相似文献   

7.
More than 300 megaspore specimens have been recovered from samples from the Late Permian, Lower Whybrow coal seam of the Wittingham Coal Measures of the Sydney Basin. Only two species are recognised: Singhisporites surangei (Singh) Potonié, emend. and a new species of Singhisporites. Species distribution within the seam is controlled by a major fire event, as recognised by coal petrology and mesofossil content: Singhisporites surangei is dominant before the event, but following it, it is subordinate to the new species.

The abundance of megaspores recovered has allowed recognition of the full range of morphologic variation of Singhisporites surangei, which encompasses specimens assigned previously to Singraulispora Pant & Mishra, 1986 and Mammilaespora Pant & Srivastava, 1961; both are regarded as junior synonyms of Singhisporites Potonié, emend. Ultrastructurally, the new species shows affinities with Mesozoic isoetalean megaspores.  相似文献   


8.
A new dicynodont genus and species, Idelesaurus tataricus sp. nov. (Cryptodontidae), from the Semin Ovrag locality (Tatarstan, Tetyushinskii District; Upper Permian, Upper Tatarian Substage, Severodvinian Horizon) is described. The skull patterns of the East European and South African Cryptodontidae and Aulocephalodontidae are compared from the morphofunctional point of view.  相似文献   

9.
Patranomodon nyaphulii , known from a nearly complete skull, lower jaw and partial postcranial skeleton, is morphologically the most primitive anomodont therapsid yet discovered. It is from the Eodicynodon Assemblage Zone, the lowest biozone of the Beaufort Group of South Africa, which has a primitive therapsid fauna comparable with that of the Russian Zone I. Patranaomodon is primitive with respect to other anomodonts in having short palatal exposure of the premaxilla, an unreduced tabular, a slit-like interpterygoidal vacuity, a screw-shaped jaw articulation (which precludes fore-aft sliding of the lower jaw), and only three sacral vertebrae. The poorly-known Galechirus and Galepus from the younger Cistecephalus Assemblage Zone appear to be at a comparably primitive evolutionary grade, and the three genera are tentatively united in the family Galechiridae. The taxon Dromasauria is shown to be paraphyletic and therefore should be discarded.  相似文献   

10.
A new species of Discinites is described from the Late Permian Upper Shihhotse Formation of the Weibei Coalfield, Shaanxi Province, China. D. hanchengensis sp. nov. has decurrent and disk-like sporophylls with deep-toothed apices, elliptical sporangia and rectangular epidermal cells. The spores are generally of the Calamospora type. The megaspores and microspores are 300–380 and 45–90 μm in diameter, respectively. The microspores are similar in size to those of all other species of Discinites that contain Calamospora, but the megaspores are remarkably smaller. The new species represents the first record of Discinites with Calamospora from China and from the Cathaysian flora. Finally, we summarize the associated foliages of Discinites in the Cathaysian flora and find that they are all markedly different from those found in the Euramerican flora.  相似文献   

11.
Reinvestigation of Nystroemia pectiniformis Halle from the Upper Shihhotze Formation of Shanxi Province, China, has led to the identification of new and important features of this enigmatic Late Permian seed plant, permitting its typification and diagnosis. After reassembling several of the previously studied specimens to form a single articulated branching system comprising at least four orders of branching, previously unknown features of its branching pattern and morphology have been characterized. First–order axes are wide and branch to one side only, bearing second–order branches either singly or in pairs and of two kinds: one fertile and bearing characteristic ovulate branching systems and the other presumably vegetative. Ovulate second–order axes are narrow and branch to one side only, producing numerous, closely spaced lateral branches in two alternate to sub–opposite rows. Lateral branches are slender and produce numerous ovulate branching systems to one side of the axis only. Ovulate branching systems divide unequally to produce 3–15 ultimate axes of different lengths that are planated. Each ultimate axis bears a single terminal ovule with 180 degree rotational symmetry and two horn–like integumentary projections distally. The other kind of second–order axes are distinct from those bearing ovules; they are wider and longer and branches occur on both sides of the secondary axis, lacking divisions in close proximity to the first–order axis. These have only been observed incomplete although their distinct morphology indicates they are unlikely to be ovulate branches from which ovules/seeds have been shed. Additional organs of the Nystroemia plant are considered, including pollen organs previously assigned by Halle to the same species (displaying its characteristic branching style), and also leaves of Chiropteris reniformis Halle that were probably borne on the larger kind of second–order branches. Implications of Nystroemia on seed plant evolution and distribution are discussed, and it is concluded that this most likely represents a late stratigraphic occurrence of a plesiomorphic hydrasperman–type seed plant with affinities closely allied to members of the Lyginopteridales.  相似文献   

12.
Specimens of the platform element of Neogondolella from the Upper Permian of the Meishan section show well-developed polygonal microsculpture on their oral surfaces, attributable to the imprints of secreting cells. In all populations studied, there is a small but significant increase of mean polygon size with element size, but no variation in polygon size related to position on the element. There is a difference in mean polygon size between the two species N. changxingensis and N. deflecta , but this appears merely to reflect the larger mean size of elements of the latter species. No evidence for periodicity of polygon size during ontogeny is detected. The population of N. changxingensis in Bed 24e is dominated by small specimens with a mean polygon size smaller than on equivalent-sized elements in the normal population of Bed 24d; this suggests that the 'dwarf' population reflects a combination of high juvenile mortality and retarded cell growth.  相似文献   

13.
Gorochov AV 《ZooKeys》2011,(130):131-136
Alexarasniidaefam. n. and Alexarasnia rossicagen. et sp. n. are described from the Upper Permian of European Russia. Systematic position of this enigmatic family within the infraclass Polyneoptera is unclear.  相似文献   

14.
15.
This paper deals with Neocalamites tubulatus nov. sp., an equisetophyte belonging to the Equisetaceae family. The material studied originates from the Upper Permian deposits of the northern part of European Russia. N. tubulatus nov. sp. is characterized by both sterile and fertile organs belonging to the same parent plant. It has long, flexible stems, rarely branched, with alternating nodes and prolonged ribs on the stem surface corresponding to vascular strands of the stem, and compact lateral strobili, in general aspect similar to the strobili of extant species of Equisetum. N. tubulatus nov. sp. is one of the most ancient representatives of the Equisetaceae family, which shows a distinct morphological pattern of features, among which the lateral position of strobili, characteristic of primitive equisetophytes, is most prominent in this phase of their evolution.  相似文献   

16.
山西柳林孙家沟组锯齿龙类新材料及其分类学意义(英文)   总被引:1,自引:0,他引:1  
记述了产自山西柳林县薛村镇附近上二叠统孙家沟组的锯齿龙类新材料,包括两个单独的上颌齿和一个保存有牙齿的不完整齿骨。这两颗上颌齿与柳林黄河龙(Huanghesaurus liulinensis)正型标本来自同一地点同一层位且大小相当,由于同一地点没发现过其他的锯齿龙类,推测它们是同种甚至可能是同一个体而且应归入黄河龙;然而在形态特征上这两颗牙齿与矮小三川龙(Sanchuansaurus pygmaeus)正型标本上的牙齿完全相同,可以归入三川龙。新发现的齿骨与矮小三川龙和薛村山西龙(Shansisaurus xuecunensis)正型标本产自同一地点,层位与三川龙相同,低于山西龙的层位,推测很可能也属于三川龙,但是也不排除属于山西龙的可能性;在形态特征上与黄河龙正型标本在齿骨及其下颌齿的形态特征上未见明显差异,可以归入黄河龙。由于柳林黄河龙与薛村山西龙头后骨骼特征也基本一致,认为柳林薛村仅有一个属种的锯齿龙,矮小三川龙和柳林黄河龙应为薛村山西龙的晚出同义名。  相似文献   

17.
Lacertoid footprints are the largest component of the Upper Permian Arenaria di Val Gardena Formation ichnofauna that contains hundreds of specimens mostly referred to the ichnogenus Rhynchosauroides Maidwell 1911. In this paper, we analyzed unpublished material and re-examined the Rhynchosauroides footprints of that ichnofauna, in particular the figured specimens. Analysis of Rhynchosauroides and its type ichnospecies R. rectipes Maidwell 1911 was first necessary. This preliminary investigation highlighted several problems, including ichnospecies named on the basis of poorly preserved material and in some cases significantly different from the type ichnospecies.

The study allowed for recognition of three ichnotaxa referred to Rhynchosauroides: Rhynchosauroides pallinii Conti et al., 1977, Rhynchosauroides isp.1 and Rhynchosauroides isp.2 and Ganasauripus ladinus igen. et isp. nov. Other material previously referred to Rhynchosauroides is herein regarded as unclassifiable, in the light of present ichnological knowledge and procedures.  相似文献   

18.
Two new genera (Sinosphaera and Trigonosphaera), including two new species and another left in open nomenclature, are described from the Changxingian (upper Permian) of southern Guangxi, southern China. They are characterized by a single spherical, subspherical or rounded triangular cortical shell composed of two spongy layers and the likely absence of both a medullary shell and internal spicule. They are tentatively grouped within the family Xiphostylidae Haeckel, 1881 and are considered as the most primitive representatives of this family.  相似文献   

19.
20.
Coprolites (fossil faeces) provide direct evidence on the diet of its producer and unique insights on ancient food webs and ecosystems. We describe the contents of seven coprolites, collected from the Late Permian Vyazniki site of the European part of Russia. Two coprolite morphotypes (A, B) contain remains of putative bacteria, cyanobacteria, fungi, protists, invertebrate eggs, arthropod elements, undigested bone and tooth fragments, fish scales and elongated hair‐like structures with hollow interiors. Content, size and shape of the coprolites together with the associated body fossil record suggest that the most probable scat‐producers were carnivorous tetrapods; the bone‐rich morphotype A reveals short food retention time and a fast metabolism and is therefore assigned to therapsid carnivores whereas morphotype B with rarer and degraded bones are assigned to archosauromorphs or other non‐therapsid carnivores. The general coprolite matrix contains abundant micron‐sized spheres and thin‐walled vesicles which are interpreted as oxide and phosphatic pseudomorphs after microbial cells. From analyses of the undigested bones, we infer that they represent remains of actinopterygian fish, a therapsid and unrecognizable parts of amphibians and/or reptiles. Additionally, hair‐like structures found in one coprolite specimen occur as diagenetically altered (oxide‐replaced) structures and moulds (or partly as pseudomorphs) in a microcrystalline carbonate‐fluoride‐bearing calcium phosphate. This suggests that the latest Permian therapsids probably were equipped with hair‐like integument or hairsuit. If true, this is by far the oldest evidence of this mammalian character in the stem group of mammals.  相似文献   

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