Record of Lower Gondwana megafloral assemblage from Lower Kamthi Formation of Ib River Coalfield, Orissa, India

Recent investigations carried out in the Ib River Coalfield, Mahanadi Master Basin, Orissa, identified some fossiliferous beds in the Lower Gondwana deposits. Two exposures of the Lower Kamthi Formation yielded diverse and abundant plant remains, which includeNeomariopteris, Vertebraria, and a scale leaf along with 14Glossopteris species otherwise mapped as Barren Measures and Upper Kamthi formations.Glossopteris indica dominates the flora (22.78%) followed byG. communis (17.72%) andG. browniana (13.92%). Based on megafloral assemblages, different beds exposed at Gopalpur and Laxamanpur Pahar are assigned here to the Lower Kamthi Formation (Late Permian). The floristic composition suggests that a warm and humid climate prevailed during the Late Permian. The status of the Kamthi Formation in the Ib River Coalfield has been redefined in the present study.     

印度Mahanadi盆地井下二叠纪下冈瓦纳岩层的微体植物化石组合

Mahanadi河盆地的冈瓦纳型诸盆地位于印度的近中心地区,呈北西—东南走向分布。Mahanadi主要盆地内的几个重要煤田为Korda煤田,Mand—Raigarh煤田和Ib河煤田。Korda煤田的冈瓦纳系沉积向南东向延伸,经Mand—Raigarh煤田延续至Ib河煤田。Korda和Ib河两个煤田储量巨大,且长期来有小构造活动;而Mand—Raigarh煤田至今很少受到重视,勘探开发晚得多。文中首次对Mand-Raigarh煤田5个钻孔样品作了孢粉研究,以初现面、相对丰度等为特征,划分出7个孢粉组合带,时代从二叠纪最早期(Talchir组)至二叠纪末期(Raniga由组)。填补了东西两个煤田之间的生物地层研究空白。7个孢粉组合带为：i)Parasaccites-Plicatipollenites assemblage zone(相当于Talchir组）,ii)Sulcatisporites-Brevitriletes assemblage zone(相当于下Barakar组）,iii)Sulcatisporites-Rhizomaspora assemblage zone(少量Densipollenites存在说明其相当于上Barakar组）,iv)Densipollenites-Striatopodocarpites assemblage zone(相当于Barren Measures组）,v)Striatopodocarpites-Densipollenites assemblage zone(相当于下Raniganj组）,vi)Striatopodocarpites-Densipollenites-Sulcatisporites assemblage zone(相当于上Raniganj组）vii)Sriatopodocarpites-Alisporites assemblage zone(相当于Raniganj最上部到Kamthi组最下部）,Raniganj组沉积中见到小的皱缩裂隙、植物垂直根和根的印痕,似代表古土壤。     

Asteriacites lumbricalis von schlotheim 1820: Ophiuroid trace fossils from the lower triassic thaynes formation,central Utah

Several trace fossils of burrowing ophiuroids, Asteriacites lumbricalis von Schlotheim 1820, occur on slabs of thinly‐bedded silty limestone in the lower Spathian part of the Lower Triassic Thaynes Formation in central Utah. This is the first record of Asteriacites in the Lower Triassic of North America. Their occurrence adds information to studies of the recovery of marine faunas following the Permian extinctions, including the oxygénation of benthic sediments.     

Permian and early Triassic isotopic records of carbon and strontium in Australia and a scenario of events about the Permian‐Triassic boundary

The negative shift in δ¹³C values of carbonate carbon at the Permian/Triassic boundary is one of the better documented geochemical signatures of a mass extinction event. The similar negative shift in δ¹³C values in organic carbon from Permian/Triassic boundary marine sediments in Austria and Canada is shown to occur also in marine and non‐marine sediments from Australian sedimentary basins. This negative shift in δ¹³C values is used to calibrate Australian sections lacking diagnostic faunal elements identifying the Permian/Triassic boundary. The minimum in the carbonate ⁸⁷Sr/⁸⁶Sr seawater curve from carbonates across the Guadalupian/Ochoan Stage boundary, mainly from North America, is shown to occur also in brachiopod calcite mainly from the Bowen Basin of eastern Australia, hence providing a second calibration point in the Australian sedimentary record. These two geochemical events support a model of a runaway greenhouse developing about the Permian/Triassic boundary; this is inferred to have contributed to the end‐Permian mass extinction.     

Pangea Megasequences of Tethyan Gondwana-margin reflect global changes of climate and tectonism in Late Palaeozoic and Early Triassic times—A review

The maximum concentration of continental crust at the Pangea stage is characterized by a specific depositional sequence generally referred to as the Pangea Megasequence. Extending in time from the Late Carboniferous to the middle of the Triassic, the succession exhibits similar trends across the whole of Gondwana. Invariably, the sequence was initiated by Late Carboniferous to Early Permian glacial and periglacial deposits. Deglaciation occurred in Early Sakmarian time, evidenced by a typical, commonly transgressive facies. The succeeding formations comprise, in ascending order, coal measures, redbeds, some more coal measures and again redbeds with an intercalation of fluviatile sands in the Early Triassic.After deglaciation the basic depositional theme was modified, depending on postglacial adjustments of climate and on the type of regional tectonic regimes. Extension of the tropical climatic belt after deglaciation was one factor that governed the resulting sediment facies. Coal deposition that prevailed in central Gondwana in the Early Permian gave way to dominance of redbeds in the Middle and Late Permian and, in more distal positions, evaporitic deposits were laid down, following deglaciation. Within marine realms, coralline limestones were formed.Within Gondwana the depositional period of the Pangea Megasequence was governed by three distinctive tectonic regimes: collision dominated the Panthalassa margin, transpressional sag controlled the interior basins, and extension and rifting was experienced along the entire Tethyan margin. In the Early Permian, large and complex graben structures commenced to develop between Africa and India (Malagasy Trough) and between India and Australia (West Australian Trough), giving access to Tethyan waters during deglaciation, commencing in the late Early Sakmarian.Rifting along the Tethyan margin commenced in the Early Permian and was associated with active volcanism between Cashmere and Yunnan and in north-western Australia. Spreading of Neo-Tethys and the formation of oceanic crust, leading to the separation of the Cimmerian Blocks from Gondwana, commenced in the late Early Permian and continued into the Triassic. Thus two facies realms developed, an intracratonic rift facies comprising the Cashmere, Lhasa and Baoshan blocks and a facies controlled by detachment, comprising more distal blocks, such as Tengchong, Malay and Sumatra. The present distribution of individual blocks was governed by fold movements of the Himalayan Orogeny, complicated by transpression along the eastern Himalayan Syntaxis.     

Bivalve Wood Borings of the Ichnogenus Teredolites Leymerie from the Bohemian Cretaceous Basin (Upper Cretaceous,Czech Republic)

Finds of fossil wood with bivalve wood borings (Teredolites clavatus and T. longissimus) occur in various facies and presumed sedimentary settings of the platform, shallow-marine Bohemian Crectaceous Basin. The basin comprises areas with sandy-dominated sediments, with marl and clay-dominated sediments, areas with predominat sandy-marly rocks, and finally areas dominated by calcareous nearshore sediments. Teredolites clavatus is common in fossil wood of sandstones, originating in beach or deltaic settings; marl and clay-dominated rock frequently bear wood fragments densely bored by Teredolites longissimus. When accompanied by evidence of marine environments as body fossils, glauconite or typical trace fossils, most of the wood fragments are bored. The presence/absence of borings in wood fragments can be considered the most reliable and easily useable criterion of distinction of marine settings in sandy sediments of the margin of the Bohemian Cretaceous Basin.     

Acyclic isoprenoids – molecular indicators of archaeal activity in contemporary and ancient Chinese saline/hypersaline environments

Acyclic isoprenoid hydrocarbons are found to be the predominant components in the organic matter extracted from sedimentary cores and oils of various hypersaline settings, including Tertiary Janghan salt lake basin, Cretaceous Taian salt lake basin, and Triassic, Permian and Cambrian Yangtze evaporitic marine platform. Inland saline lake basins are characterized by tremendous predominance of phytane (iC20) ranging up to 15% of the total extract. While the evaporitic marine sediments are unique for their complete series of super-long-chain acyclic isoprenoids, up to C40. These isoprenoids possess head-to-head, tail-to-tail or regular linkages and generally are indicators of the significant contribution from various archaea (archaebacteria), i.e. halophiles, methanogens and acidothermophiles. According to the great discrepancy of distribution and composition of isoprenoids, these modern and Cenozoic inland salt lake sediments are likely dominated by halophilic archaea, while the studied Mesozoic and Paleozoic evaporitic marine sediments are predominantly distinguished by methanogens and acidothermophiles. Concentration of chlorine salt is more directly proportional to the abundance of phytane than sulfate. Reduced species of sulfur, sulfide, S0 and organic sulfur compounds (OSC), however, may have played a key role in the preservation and formation of the highly abundant phytane observed in the inland salt lake basins. This revised version was published online in July 2006 with corrections to the Cover Date.     

A new scanilepiform from the Lower Triassic of northern Gansu Province,China, and phylogenetic relationships of non‐teleostean Actinopterygii

A new scanilepiform, Beishanichthys brevicaudalis gen. et sp. nov. , is named and described based on fossils from the Lower Triassic lake deposits exposed in Beishan area, Gansu Province, China. The discovery documents a new record of this group, which is significantly older than other known scanilepiforms from China, and is slightly younger than Evenkia from the Lowest Triassic of Central Siberia. Although the Beishan beds were previously interpreted as Late Permian in age, based on megaplant fossils, this new discovery supports the reinterpretation of the deposits as Early Triassic in age, based on vertebrate fossils from the same locality and horizon. Phylogenetic analysis was conducted to resolve the relationships of Scanilepiformes with other actinopterygian clades, and the inter‐relationships within Scanilepiformes. Contrary to previous thought that scanilepiforms are closely related to the Amiidae, the phylogenetic results of this study recognize the Scanilepiformes as stem‐group neopterygians. Relationships of the Scanilepiformes and Australosomus with other neopterygians remain unresolved. With a characteristic long‐based dorsal fin, scanilepiforms represent a small group that emerged in Early Triassic freshwater environments, inhabited Eurasia and North America during the Middle–Late Triassic, briefly invaded the marine environment by the Late Triassic in Europe, and became extinct at the end of Triassic. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 595–612.     

Permian and Triassic Radiolaria from Northwest Thailand: paleogeographical implications

Well-preserved radiolarians were recovered from seven sections in the Mae Hong Son-Mae Sariang area, northwestern Thailand. 51 species assigned to 34 genera are identified, including 1 new species (Triassospongosphaera erici Feng sp. nov.) and 19 unidentified species. They are divided into the Late Permian, late Ladinian and middle Carnian radiolarian assemblages. Newly identified radiolarian assemblages, together with the published radiolarian biostratigraphic data from this region, indicate that there was a pelagic basin during the Late Paleozoic and Triassic. This basin was joined to the Chiang Dao and Changning-Menglian oceanic basins, and they represent the main oceanic basin of the Paleotethyan Archipelago Ocean. This main oceanic basin was situated in the traditional “Shan-Thai Block”. Therefore, “the Shan-Thai Block” was not a single block during that stage, but composed of the Paleotethyan Ocean and two continental terranes that were affiliated with the Gondwana and Cathaysian domains, respectively.     

The Permian–Triassic transition and the onset of Mesozoic sedimentation at the northwestern peri-Tethyan domain scale: Palaeogeographic maps and geodynamic implications

The main aim of this paper is to review Middle Permian through Middle Triassic continental successions in European. Secondly, areas of Middle–Late Permian sedimentation, the Permian–Triassic Boundary (PTB) and the onset of Triassic sedimentation at the scale of the westernmost peri-Tethyan domain are defined in order to construct palaeogeographic maps of the area and to discuss the impact of tectonics, climate and sediment supply on the preservation of continental sediment.At the scale of the western European peri-Tethyan basins, the Upper Permian is characterised by a general progradational pattern from playa-lake or floodplain to fluvial environments. In the northern Variscan Belt domain, areas of sedimentation were either isolated or connected to the large basin, which was occupied by the Zechstein Sea. In the southern Variscan Belt, during the Late Permian, either isolated endoreic basins occurred, with palaeocurrent directions indicating local sources, or basins underwent erosion and/or there was no deposition. These basins were not connected with the Tethys Ocean, which could be explained by a high border formed by Corsica–Sardinia palaeorelief and even parts of the Kabilia microplate. The palaeoflora and sedimentary environments suggest warm and semi-arid climatic conditions.At the scale of the whole study area, an unconformity (more or less angular) is observed almost everywhere between deposits of the Upper Permian and Triassic, except in the central part of the Germanic Basin. The sedimentation gap is more developed in the southern area where, in some basins, Upper Permian sediment does not occur. The large sedimentary supply, erosion and/or lack of deposition during the Late Permian, as well as the variable palaeocurrent direction pattern between the Middle–Late Permian and the Early Triassic indicate a period of relief rejuvenation during the Late Permian. During the Induan, all the intra-belt basins were under erosion and sediment was only preserved in the extra-belt domains (the northern and extreme southern domains). In the northern domain (the central part of the Germanic Basin), sediment was preserved under the same climatic conditions as during the latest Permian, whereas in the extreme southern domain, it was probably preserved in the Tethys Ocean, implying a large amount of detrital components entering the marine waters. Mesozoic sedimentation began in the early Olenekian; the ephemeral fluvial systems indicate arid climatic conditions during this period. Three distinct areas of sedimentation occur: a northern and southern domain, separated by an intra-belt domain. The latter accumulated sediments during the Early–Middle Permian and experienced erosion and/or no-deposition conditions between the Middle–Late Permian and the beginning of Mesozoic sedimentation, dated as Anisian to Hettangian. At the top of the Lower Triassic, another tectonically induced, more or less angular unconformity is observed: the Hardegsen unconformity, which is dated as intra-Spathian and is especially found in the North European basins. This tectonic activity created new source areas and a new fluvial style, with marine influences at the distal part of the systems. During the Anisian and Ladinian, continental sedimentation was characterised by a retrogradational trend. In other words, the fluvial system evolved into fluvio-marine environments, attesting to a direct influence of the Tethys Ocean in the southern and northern domains. Both at the end of the Olenekian (Spathian) and during the Anisian, the presence of palaeosols, micro- and macrofloras indicate less arid conditions throughout this domain.     

Allometry in Anisian (Middle Triassic) segminiplanate conodonts and its implications for conodont taxonomy

Conodonts are a clade of chordates and are valuable indicator fossils for biostratigraphy. The segminiplanate (neogondolelliform) conodonts represent a major morphological group ranging from upper Carboniferous to Upper Triassic marine sediments. However, the morphological similarity of segminiplanate P₁ elements generates problems for taxonomy, especially in the Permian and Triassic clades. This paper represents the first study of morphological variation in Triassic segminiplanate conodonts using a geometric morphometric approach. The laminar microstructures observed in conodont cross‐sections indicate that, within our analysed specimens, smaller conodonts with fewer laminae are generally from an earlier ontogenetic stage while larger conodonts with more laminae are from a later stage of ontogeny. Using linear regressions between relative warp scores from both upper and lateral views and conodont length, we demonstrate strongly allometric growth patterns for the species Paragondolella bifurcata Budurov & Stefanov. Our results indicate that the species‐group taxon Pg. praeszaboi bystrickyi (Kovacs et al.) is an early growth stage of Pg. bifurcata and thus synonymous. We suggest that the allometry of conodonts should be considered seriously, especially when there are numerous transitional morphologies between large‐ and small‐sized conodonts. Reconstructing the ontogenetic series and using larger‐sized conodonts within the numerous transitional morphologies in the population of a rock sample for the definition of new species are suggested for future studies.     

Global deglaciation and the re‐appearance of microbial matground‐dominated ecosystems in the late Paleozoic of Gondwana

The extensive matgrounds in Carboniferous‐Permian open‐marine deposits of western Argentina constitute an anachronistic facies, because with the onset of penetrative bioturbation during the early Paleozoic microbial mats essentially disappeared from these settings. Abundant microbially induced sedimentary structures in the Argentinean deposits are coincident with the disappearance of trace and body fossils in the succession and with a landward facies shift indicative of transgressive conditions. Deposits of the Late Carboniferous–Early Permian glacial event are well developed in adjacent basins in eastern Argentina, Brazil, South Africa and Antarctica, but do not occur in the western Andean basins of Argentina. However, the deglaciation phase is indirectly recorded in the studied region by a rapid rise in sea level referred to as the Stephanian‐Asselian transgression. We suggest that an unusual release of meltwater during the final deglaciation episode of the Gondwana Ice Age may have dramatically freshened peri‐Gondwanan seas, impacting negatively on coastal and shallow‐marine benthic faunas. Suppression of bioturbation was therefore conducive to a brief re‐appearance of matground‐dominated ecosystems, reminiscent of those in the precambrian. Bioturbation is essential for ecosystem performance and plays a major role in ocean and sediment geochemistry. Accordingly, the decimation of the mixed layer during deglaciation in the Gondwana basins may have altered ecosystem functioning and geochemical cycling.     

Microbialites and trace fossils from a Middle Triassic restricted carbonate ramp in the Catalan Basin,Spain: evaluating environmental and evolutionary controls in an epicontinental setting

The timing of recovery after the end‐Permian mass extinction has been a matter of debate, with some authors favouring a more rapid faunal recovery during the Early Triassic and others considering a more protracted biotic reestablishment spanning until the Middle Triassic. In this work, we investigated the lowermost Middle Triassic (Ladinian) carbonate deposits in the Catalan Basin to evaluate the potential environmental mechanisms and evolutionary constrains involved in the kilometre‐scale predominance of microbialites and the low‐diversity and high‐density Planolites association in a low‐latitude epicontinental setting. The studied sedimentary succession records the development from a low‐gradient, homoclinal microbial‐dominated carbonate ramp evolving towards a slightly inclined swell‐dominated type. Sedimentological analysis suggests that facies heterogeneity was controlled by pulses of syn‐rift tectonic activity, which compromised Peri‐Tethyan basin connectivity, reducing palaeobathymetry gradients. Although the monospecific nature of the studied trace‐fossil association may reflect the delayed recovery after the end‐Permian mass extinction, this is inconsistent with widespread, relatively high‐diversity ichnofaunas in carbonates elsewhere in the region. Since other Ladinian basins were characterized by the recurrence of microbial carbonates, low‐diversity ichnoassemblages and limited skeletal production, we hypothesize that shallow and restricted carbonate ramp settings harboured limited ecological complexity and widespread opportunistic colonization of the sediment when compared to coeval open marine locations.     

High organic carbon content and a decrease in radiolarians at the end of the Permian in a newly discovered continuous pelagic section: A coincidence?

The greatest mass extinction occurred at the end of the Permian. Most records of the mass extinction are not from pelagic sediments, but from shallow-marine and terrestrial sediments. Although several pelagic sections that span the end-Permian mass extinction have been found, these sections contain few index fossils and are often discontinuous because of small faults. We found the index fossils Albaillella cf. triangularis (Radiolaria) in siliceous claystone beds, Hindeodus parvus (Conodont) in the overlying black claystone beds, and Neospathodus cf. cristagalli and Ns. waageni (Conodont) in the subsequent siliceous claystone beds in Akkamori section-2 in northern Japan. These fossils suggest that this section ranges from the late Permian to the Early Triassic, including the early Induan and Olenekian stages. Furthermore, the lithological changes in the section, i.e., starting from bedded chert through siliceous claystone and black claystone to siliceous claystone, are concordant with those of well-known Permian–Triassic pelagic sequences in Japan. There is no gap between each lithofacie of the Akkamori section-2. Critical lithological continuity between Upper Permian siliceous claystone beds and uppermost Permian to lowermost Triassic black claystone beds of the Akkamori section-2 was recognized by observing hand-polished specimens and thin sections. Such paleontological and sedimentological evidence implies that the Akkamori section-2 is a continuous pelagic section that records the end-Permian mass extinction event. The carbonaceous black claystone beds have high total organic carbon (TOC) concentrations (1.06–3.31 wt.%), suggesting oceanic anoxia at least deep and probably stable primary productivity. A decrease in radiolarian abundance from 26–563 to 0.27–20 specimens/cm² coincided with an increase in TOC content from 0.01–0.16 to 1.06–3.31 wt.% at the boundary of the siliceous claystone and the overlying black claystone beds near the top of the Permian, implying that radiolarian extinction occurred at the end of the Permian coinciding with oceanic anoxia. Although TOC contents decreased in the early Olenekian (Smithian), radiolarian abundance did not increase at that time, indicating that radiolarian recovery was delayed by > 1.5 m.y.     

Late Paleozoic–early Mesozoic continental biostratigraphy — Links to the Standard Global Chronostratigraphic Scale

Nonmarine biostratigraphic/biochronologic schemes have been created for all or parts of the late Carboniferous–Middle Triassic using palynomorphs, megafossil plants, conchostracans, blattoid insects, tetrapod footprints and tetrapod body fossils, and these provide varied temporal resolution. Cross correlation of the nonmarine biochronologies to the Standard Global Chronostratigraphic Scale has been achieved in some parts of the late Carboniferous–Middle Triassic in locations where nonmarine and marine strata are intercalated, the nonmarine strata produce biochronologically significant fossils and the marine strata yield fusulinids, conodonts and/or ammonoids. Other cross correlations have been aided by magnetostratigraphy, chemostratigraphy and a growing database of radioisotopic ages. A synthetic nonmarine biochronology for the late Carboniferous–Middle Triassic based on all available nonmarine index fossils, integrated with the Standard Global Chronostratigraphic Scale, is presented here. The focus is on the nonmarine biostratigraphy/biochronology of blattoid insects, conchostracans, branchiosaurid amphibians, tetrapod footprints and tetrapod body fossils within the biochronological framework of land-vertebrate faunachrons. Correlation to the Standard Global Chronostratigraphic Scale presented here is divided into seven time intervals: Pennsylvanian, Carboniferous–Permian boundary, Cisuralian, Guadalupian, Lopingian, Permian–Triassic boundary and Early to Middle Triassic. The insects, conchostracans and branchiosaurs provide robust nonmarine correlations in the Pennsylvanian–Cisuralian, and the footprints and tetrapod body fossils provide robust correlations of varied precision within the entire Pennsylvanian–Middle Triassic. Radioisotopic ages are currently the strongest basis for cross correlation of the nonmarine biostratigraphy/biochronology to the Standard Global Chronostratigraphic Scale, particularly for the Pennsylvanian–Cisuralian. Chemostratigraphy and magnetostratigraphy thus far provide only limited links of nomarine and marine chronologies. Improvements in the nonmarine-marine correlations of late Paleozoic–Triassic Pangea require better alpha taxonomy and stratigraphic precision for the nonmarine fossil record integrated with more reliable radioisotopic ages and more extensive chemostratigraphic and magnetostratigraphic datasets.     

SYSTEMATIC REVISION OF PSEUDOBEACONIA BORDAS, 1944, AND MENDOCINICHTHYS WHITLEY, 1953 (ACTINOPTERYGII: ‘PERLEIDIFORMES’) FROM THE TRIASSIC OF ARGENTINA

Abstract: The ‘perleidiform’Mendocinichthys and Pseudobeaconia from the Potrerillos and Santa Clara Abajo formations (Upper Triassic; Argentina) are reviewed. Mendocinichthys has been known from a review of this species that is not based on the type material, but on referred specimens in the American Museum of Natural History. However, those specimens are found here to represent a new species of Pseudobeaconia, P. celestae sp. nov. Consequently, Mendocinichthys is restricted here to the type material and, within it, to the only specimen that clearly represents a distinct taxon and is thus designated lectotype. We further performed a cladistic analysis and propose a new family, Pseudobeaconiidae for these two South American Triassic genera, which is mainly characterized by the presence of an incomplete dorsal ridge of spine‐like scales between the skull and the dorsal fin, and scales with straight posterior border, an elevated central region and marginal concentric ridges of ganoine. The cladistic analysis further indicates the existence of some lineages endemic to certain areas of Gondwana and Europe. Pseudobeaconia celestae sp. nov. represents the first record of Pseudobeaconia in the Cacheuta sub‐basin of the Cuyana Basin. The genus was previously known from the Santa Clara sub‐basin of the Cuyana Basin only, and the new record confirms the previous hypothesis of correlation between the sedimentary infilling of these sub‐basins.     

New beetles (Insecta,Coleoptera) from the Lower Triassic of European Russia

Fossil remains of beetles are described from two Lower Triassic localities: Entala (Induan) and Tikhvinskoe (Olenekian). Only one beetle fossil was previously known from the Lower Triassic of Tikhvinskoe. The fossils are rather few and poorly preserved, but they are worth describing as finds rare for the Lower Triassic. Five fossils from Entala most probably belong to beetles of the same species of the formal genus Pseudochrysomelites. Beetles of this genus are especially abundant in deposits close to the Permian–Triassic boundary and can be considered “disaster taxa.” There are no known cases, either in the Permian or in the Middle–Upper Triassic, of a random sample of five specimens belonging to a single species. This suggests that in the Entala oryctocenosis the species diversity of beetles is extremely low. All three beetle fossils found in Tikhvinskoe belong to beetles of different species, showing that diversity had already started to increase. However, it remained low, and all fossils belong to the formal family Schizocoleidae, and two of the three belong to the same genus, Pseudochrysomelites. The Khei-Yaga locality, which immediately follows Tikhvinskoe in time (topmost Olenekian or early Anisian), already contains beetles of the families Asiocoleidae and Permosynidae. In the Lower Anisian of the Buntsandstein, such typical Mesozoic beetles as Cupedidae and Coptoclavidae have been recorded. The appearance of such advanced beetles as early as the Lower Anisian suggests that the famous Permian–Triassic crisis was not as deep as it is usually believed, and many beetles survived it, disappearing, however, from the fossil record in the Early Triassic.