Carboniferous and Permian biostratigraphy by foraminifers and calcareous algae of Bir Mastoura (BMT-1) and related boreholes of southern Tunisia

In South Tunisia, the Bir Mastoura (BMT-1) borehole provides Carboniferous, Permian, and early Triassic foraminifers and carbonate algae which permit to establish a local biozonation which can be correlated with (1) the Capitanian (Late Middle Permian) outcrops of Jbel Tebaga; (2) other Tunisian boreholes; and (3) several stratotypes and/or well-studied Tethyan outcrops. Microfacies, microfaunas and microfloras of BTM-1 reveal subtropical, carbonate, inner platform deposits. As everywhere in the world, the Early Triassic is faunistically very poor. The Upper Permian and Upper Middle Permian microfaunas and microfloras are traditional in Tunisia, but a little poorer than the Tebaga assemblages. The fusulinids of the middle and lower Middle Permian strata are also less numerous than in other Tunisian boreholes. The late Pennsylvanian fusulinids known in some of these boreholes, were not observed in BMT-1; however, these fusulinids are re-discussed here due to their biostratigraphic and palaeobiogeographic importance; they are assigned to two substages, early Gzhelian with Darvasoschwagerina spp. and late Kasimovian with Schwageriniformis petchoricus. Neither early-middle Kasimovian nor late Moscovian microfossils were found, and their absence is probably regional in the whole North Africa. In contrast, the early Moscovian beds yield all the fusulinid biozones of the Urals (Russia) and display diversified microfauna with Profusulinella aff. simplex, Ovatella ex gr. ovata; Depratina timanica, Aljutovella (Tikhonovichella) rhombiformis, Hemifusulina spp., Eofusulina aff. tashlensis, Paraeofusulina trianguliformis, Moellerites cf. praecolaniae and Parabeedeina cf. pseudoelegans. The middle-late Bashkirian seems to be only partially represented, whereas the early Bashkirian is similarly relatively complete, with Varvariella ex gr. varvariensis, Plectostaffella cf. karsaklensis, P.? nauvalia, Semistaffella? sp. and common oolitic microfacies. The Serpukhovian and late Visean appear more developed than in other boreholes. They yield Praedonezella, Eosigmoilina and Endostaffella. As across the North Africa, no older Mississippian foraminifers are not known prior to the late Visean. The palaeogeography is discussed thanks to the regional new data; especially the concept of a Saharan province, or its replacement by multiple aborted rifts during the late Visean-Serpukhovian. From the Bashkirian to Early Permian, affinities with Croatia are frequent. Comparisons with other North African basins, northern Spain, Donets Basin, the Urals basins, Moscow Basin, Taurus and Alborz are also presented.     

Late Bashkirian and early Moscovian conodonts from the Naqing section,Luodian, Guizhou,South China

Late Bashkirian and early Moscovian conodonts are abundant and diverse at the Naqing section, South China. All conodont genera known to have numerous species in the late Bashkirian–early Moscovian are recorded here, including Declinognathodus, Diplognathodus, Gondolella, Idiognathodus, Idiognathoides, Mesogondolella, Neognathodus, and Neolochriea. At Naqing, many species of these genera provide a succession of conodont chronomorphoclines throughout the Bashkirian–Moscovian boundary interval. They demonstrate that deposition was remarkably continuous through the boundary interval, a major criterion for selecting a Global Stratotype Section and Point (GSSP). This paper describes the current state of knowledge for several of these chronomorphoclines, and also provides an updated range chart of conodonts recovered from the Naqing section and their correlation with other regions.The taxon that best matches the current concept for the base of the Moscovian Stage in its type region is the phylogenetic first occurrence of Diplognathodus ellesmerensis. An ancestral form with most of the characteristics of D. ellesmerensis occurs at Naqing. More specimens are needed to completely document the chronomorphocline, but because D. ellesmerensis is found worldwide — including that close to the base of the type Moscovian — its evolutionary first occurrence would provide an almost ideal GSSP to define the base of the international Moscovian Stage.     

Paleobiogeographic significance of a new ozawainelloid fusulinid Pseudoacutella partoazari n. sp., from the Asselian (lowermost Permian) of Gaduk (Central Alborz,Iran)

The uppermost Carboniferous–Lower Permian Dorud Group that crops out at the Gaduk section of Central Alborz is over 44 m thick and includes thick sequences of conglomerate, quartzarenite, calcareous sandstone, oncolitic fusulinid limestone, sandy limestone, sandstone and shale. The Toyeh, Emarat and Shah Zeid formations of this Group were dated as latest Gzhelian to Early Sakmarian. A review of the Asselian fusulinids and smaller foraminifers of Iran emphasizes (1) how the foraminiferal assemblages of Alborz and central Iran differ; (2) why non-Pseudofusulina cannot be a nomen substitutum to Pseudofusulina (even if this latter was often misinterpreted in the Tethyan regions). A new smaller fusulinid Pseudoacutella partoazari n. sp. is described from the Emarat Formation (Asselian) that crops out in the Gaduk area. The palaeobiogeographic significance of Pseudoacutella is discussed, because this genus, which was cosmopolitan from Late Bashkirian to Moscovian, became rare in the Upper Pennsylvanian of the USA and the Carnic Alps, and then, very rare in Lower Permian of Texas, Arizona and Iran.     

Pennsylvanian fusulinids and calcareous algae from Sonora (northwestern Mexico), and their biostratigraphic and palaeobiogeographic implications

Pennsylvanian carbonates are widespread in Sonora (Mexico) and contain a diverse biota of foraminifers and calcareous algae. Detailed studies here are devoted to the outcrops of the Sierra Agua Verde and Cerro El Tule. The Late Atokan (early Late Moscovian part), Desmoinesian (= late Late Moscovian) and Missourian (= Kasimovian) stages are especially rich in fusulinids and algae. The principal zones of fusulinids of Wilde encountered are A3, DS1 and MC1–2. New data are given about the genera Fusulinella, Parawedekindellina, Zellerella, Komia and Paraepimastopora, in order to establish migrations or vicariances between Mexico and Palaeotethys.     

Funsulinid assemblages and facies of the Bombaso Fm. and basal meledis Fm. (Moscovian-Kasimovian) in the central Carnic Alps (Austria/Italy)

Summary The Bombaso Formation and basal Meledis Formation in the central Carnic Alps near Straniger Alm and Zollnersee (Austria/Italy) unconformably overlie the folded Variscan basement and consist of shallow marine clastic and carbonate sediments which are arranged to form two fining and deepening upward sequences. Particularly limestones and even breccias of the Bombaso Formation yielded a rich fusulinid fauna composed of 34 species which are attributed to the following zones:Quasifusulinoides quasifusulinoides-Protriticites ovatus; Protriticites pseudomontiparus, andMontiparus montiparus. Breccias of the Bombaso Formation west of Straniger Alm contain the oldest fusulinid fauna of the Carnic Alps, belonging to theQuasifusulinoides quasifusulinoides —Protriticites ovatus zone. The fauna is composed ofQuasifusulinoides quasifusulinoides, Q. fallax, Q. intermedius, Protriticites cf.ovoides, andPr. ovatus. This assemblage is most similar to that of the Peskovskaya Formation of the Myachkovian Horizon in the Moscow Basin indicating uppermost Moscovian age. Limestones from depositional sequence 1 at Zollnersee also contain fusulinids of the uppermost Moscovian which are characterized by a more diverse assemblage:Schubertella donetzica, Fusiella lancetiformis, Beedeina ulitinensis, B. consobrina, B. nytvica, B. siviniensis, Quasifusulinoides pakhrensis, Q. fallax, Q. kljasmicus, Q. quasifusulinoides, Fusulinella rara, andProtriticites ovatus. Limestones and calcareous sandstones-siltstones of the basal Meledis Formation of depositional sequence 2 near Zollnersee and at Cima Val di Puartis are characterized by fusulinids of theProtriticites pseudomontiparus zone (Protriticites globulus, Pr. pseudomontiparus, Pr. sphaericus, Pr. rotundatus, Pr. ovoides, Pr. lamellosus, andPraeobsoletes burkemensis) and byMontiparus paramontiparus zone (Praeobsoletes pauper, P. burkemensis, Obsoletes timanicus, O. obsoletes, Montiparus paramontiparus, M. umbonoplicatus, M. montiparus, M. likharevi, M. rhombiformis andM. priscus) indicating lower to middle Kasimovian age (Krevyakinskian and Khamovnicheskian Horizons of the Russian Platform). In memoriam FranzKahler (1900–1995)     

Lopingian (Late Permian) brachiopods around the Wuchiapingian-Changhsingian boundary at the Meishan Sections C and D, Changxing, South China

The strata below the defined Wuchiapingian-Changhsingian boundary GSSP are mostly covered and obscured by faulting at the Meishan Section D. Therefore, it is very difficult to collect fossils there. After an intensive excavation at Meishan Section C, a diverse fauna based on high-resolution biostratigraphy comprising brachiopods, ammonoids, conodonts, fusulinids and small foraminifers were found. Among these fossils, brachiopods are the most dominant. Eleven species of 10 genera based on more than 1300 specimens are identified. This brachiopod fauna is of late Wuchiapingian-Changhsingian of Lopingian (Late Permian) in age as well constrained by the associated ammonoid Pseudogastrioceras sp., Jinjiangoceras and Konglingites sp., the fusulinid Palaeofusulina and the conodont lineage from C. longicuspidata to C. wangi. In terms of the changes of brachiopod fauna composition around Wuchiapingian-Changhsingian boundary, it clearly indicates a continuous transgression from the upper part of the Lungtan Formation to the lower part of the Changhsing Formation. A new species, Neochonetes (Huangichonetes) meishanensis, is described and some other species are discussed based on the new collection from Meishan Sections C and D.     

Evolution of the fusulinid Depratina in the Bashkirian–Moscovian interval

The genera Staffellaeformes and Depratina are widespread in Lower and Middle Pennsylvanian rocks of Eurasia and are important for Pennsylvanian biostratigraphy. The lineage Staffellaeformes–Depratina represents one of several major trends in the fusulinid evolution recorded in the Bashkirian–Moscovian. The genus Depratina first appeared in the late Bashkirian but continued and thrived in the Moscovian. In the Southern Urals, Depratina prisca first appeared close to the base of the Moscovian, and can be used as a marker for this boundary.     

中国晚石炭世达拉阶标准剖面的(筳)

详细研究达拉阶标准剖面的ting化石,计有14属74种及亚种,其中未定种1种,建立6个ting化石带,自下而上依次为：Profusulinella priscoidea-P．parva带,Profusulinella aljutovica-Taitzehoella taitzehoensis extensa带,Fusulinella obesa-F．eopulchra带,Fusulina lanceolata-Fusulinella vozhgalensis带,Fusulina pakhrPnsis-Pseu-dostaffella paradoxa带及Fusulina cylindrica-F,quasifusulinoides带。标准剖面的达拉阶应与国际地层表中的巴什基尔阶上部和莫斯科阶相当。     

Palaeoaplysinella gen. nov. and Likinia Ivanova and Ilkhovskii, 1973 emend., from the type Moscovian (Russia) and the algal affinities of the ancestral palaeoaplysinaceae n. comb

Because of the cellular tissue often described and occasionally confused in the literature with some Archaeolithophyllum, an assignment to the red algae Archaeolithophyllaceae is proposed for Palaeoaplysinaceae nomen translat., herein. Archaeolithophyllaceae, Palaeoaplysinaceae and several “phylloid algae” might compose the order Archaeolithophyllales nom. translat. A new ancestral form of the primitive paleoaplysinaceans is described in the Podolskian (early late Moscovian) of the Moscow Basin, under the name Palaeoaplysinella n. gen. with P. moscovica n. sp., as type species. These forms, proportionally small, do not construct reefal structures, and is reworked in bioclastic grainstone rich in algae and fusulinids. Its structure differs from the following late Moscovian forms previously described as palaeoaplysinaceans: (a) Likinia from the Podolskian-Myachkovian deposits of the Moscow basin and (b) the Desmoinesian palaeoaplysines mentioned in Utah (USA) (a taxon to re-describe). Likinia is revised herein. Its type species does not belong to the palaeoaplysinaceans; nevertheless, its assignment is uncertain. Since their origin, the Palaeoaplysinaceae colonized the shelf seas of the northern subtropical to warm-temperate provinces (from 15 to 45°N) including the Urals, Greenland, Canadian Arctic Archipelago, some parts of the North American Craton and the Klamath Exotic Terrane (California). The adjacent regions of the southern USA, northern Mexico (Sonora), Pericaspian, and Donbass have not been colonized. The history of Palaeoaplysinacea is probably linked to the evolution of the Ural Ocean. Based on these reconstructed paleolatitudes, the Akiyoshi Terrane in Japan, which contains rare Palaeoaplysina, was emplaced between 15 and 45° North latitude during the Asselian (earliest Permian).     

The schulterkofel section in the Carnic Alps,Austria: Implications for the carboniferous-permian boundary

Summary The upper part of the LowerPseudoschwagerina Limestone (Rattendorf Group), outcropping on the northwestern flank of Schulterkofel Mountain, Carnic Alps (Austria) is described with special emphasis on fusulinid microfossils and facies. This fusulinid-rich section offers an ideal opportunity for biostratigraphy in defining the Permo-Carboniferous boundary in this region. The LowerPseudoschwagerina Limestone is composed of shallow-marine limestones with intercalated thin siltstone and sandstone beds. Fusulinid limestones are represented by two types of wackestones, both containing large quantities of smaller foraminifers. Fusulinid grainstones are rare. Limestones rich in fusulinids were found only within the bedded limestone facies in beds both below and especially above siliciclastic intercalations. This may indicate that the best living conditions for fusulinids existed immediately before and especially after the climax of a regressive phase (sea-level lowstand). The fusulinid limestones were deposited within a protected, shallow-marine shelf environment with normal salinity. Pseudoschwagerinid fusulinids appear in the upper part of the LowerPseudoschwagerina Limestone, in samples SK 107d (undeterminable species) and SK 108, i.e. between 92 m and 93 m above the base of the section within a bedded limestone immediately above the uppermost clastic intercalation. The fusulinid fauna is represented by about 30 species belonging to only a few genera. Species ofTriticites andRugosofusulina dominate, whereas those ofDaixina, Rugosochusenella andPseudofusulina are rare. A characteristic feature of the fauna is the strong similarity with fusulinid faunas described from Russia as well as from Middle and East Asia. Some of the described fusulinids are new for the Carnic Alps. The first appearance ofPseudoschwagerina andOccidentoschwagerina (Occidentoschwagerina alpina Zone) in the upper part of the LowerPseudoschwagerina Limestone in the Schulterkofel section defines the position of the Carboniferous-Permian boundary.     

福建沙县船山组的(竹蜓)类

通过对福建沙县高地村石灰岩矿区船山组类的系统研究 ,共描述类 13属 70种 ,包括 7个新种和 3个未定种。根据类在地层中的分布和垂向变化规律 ,自下而上建立了 5个类化石带 :1) Triticites shikhanensis com-pactus带 ,2 ) Pseudoschwagerina miharanoensis带 ,3) Zellia chengkungensis带 ,4 ) Sphaeroschwagerina sphaerica带 ,5 ) Eoparafusulina pararegularis带 ,为该区船山组地层的划分和对比以及我国石炭 -二叠系界线的深入研究提供重要的科学依据。     

Late Moscovian (mid-Pennsylvanian) rugose corals from Wadi Araba (Egypt,Eastern Desert): Taxonomy,palaeoecology and palaeobiogeography

An important late Moscovian rugose coral association is described from the Rod El Hamal Formation of the Wadi Araba area (northern Eastern Desert, Egypt). The upper part of the formation yielded a moderately abundant but poorly diversified coral fauna composed of large dissepimented solitary rugose corals. In total, six species belong to the Bothrophyllidae and the Geyerophyllidae, including three new species: Bothrophyllum suezensis, Bothrophyllum cylindricum, and Amygdalophylloides omarai. Three undeterminable Bothrophyllidae taxa are left in open nomenclature. The corals were attached to the soft substrate by talons and rootlets, either rooted and growing upward as mud-stickers or as secondary recliners. They show frequent rejuvenations and constrictions. Encrustation and/or bioerosion are scarce. Carbonate microfacies indicate a habitat in littoral and inner neritic zones adjacent to a low terrigenous hinterland. Colonial taxa are missing and tabulate corals are rare. The corals from the Rod El Hamal Formation are the only example of a late Moscovian coral fauna on the southern margin of the Palaeotethys, that is to say along the northern margin of Gondwana. The association shows similarities with northwestern Spain (Cantabrian Mountains), the Donets and Moscow basins, and thus a general attribution to the Palaeotethys realm.     

New Pennsylvanian (Moscovian) echinoderms from Xinjiang Uyghur Autonomous Region,western China

The few Pennsylvanian echinoderm faunas reported from the Paleotethys are from China, Japan, and Australia. The Japanese and Chinese faunas contain camerates that are rare in Pennsylvanian faunas worldwide.Genera of one monobathrid camerate, two disparids, five cladids, one flexible, one blastoid, and one archaeocidarid are reported from the late Moscovian uppermost part of the Qijiagou Formation or lowermost part of the Aoertu Formation in the Taoshigo Valley near Taoshuyuan Village, Xinjiang Uyghur Autonomous Region, China. They are here referred to as the Aoertu fauna, which is most closely allied with Pennsylvanian crinoids reported from a slightly older fauna from the Qijiagou Formation in the Taoshigo Valley and with faunas known from Japan and North America. Most taxa are identified to the genus level and left in open nomenclature because of poor or partial preservation. In addition, camerate ossicles and a cup of Synbathocrinus are reported from the early Moscovian part of the Sanquanzi Formation at Yamansu, southeast of the Taoshigo Valley. New taxa described are: Synbathocrinus labrus n. sp., Stellarocrinus qijiagouensis n. sp. and Metaperimestocrinus aoertuensis n. sp.     

Middle-late Asselian (Early Permian) fusulinid fauna from the post-Variscan cover in NW Anatolia (Turkey): Biostratigraphy and geological implications

The earliest autochthonous cover of the Variscan basement of the Sakarya Composite Terrane (SCT) in NW Anatolia is represented by basal conglomerates and limestones. The microfacies types of the limestones in ascending order are: (1) bioclastic grainstone/packstone, (2) fusulinid grainstone/packstone, (3) smaller foraminiferal grainstone/packstone, (4) Anthracoporella (dasycladale) grainstone/packstone, and (5) wackestones. Twenty-three species assignable to 15 genera of fusulinids were recovered from the studied materials of the Kadirler section; Quasifusulinaguvenci nov. sp. and Pseudoschwagerinabeedeimagna nov. subsp. are created. Rugosofusulinids, sphaeroschwagerinids, pseudoschwagerinids, occidentoschwagerinids, pseudochusenellids, quasifusulinids, rugosochusenellids and paraschwagerinids are the main faunal elements of the succession, which shows two distinct faunal intervals. Eoschubertella, Schubertella, Biwaella?, Rugosofusulinastabilis group, and Pseudochusenella correspond to the first interval at the base; the second interval is characterized by the species of Sphaeroschwagerina, Pseudoschwagerina,Occidentoschwagerina, the Rugosofusulinalatispiralis group, and diverse quasifusulinids. A biostratigraphic correlation shows that the Kadirler section in the SCT in NW Anatolia shares many common species with Central Asia in the East but especially with the Carnic Alps and Karavanke Mountains in the West. The new data suggest that the close faunal relationship in the Late Carboniferous between eastern Alps, Ural Mountains, NW Turkey and Central Asia also continued during the Asselian.     

Biostratigraphical analysis of the Moscovian–Kasimovian transition at the neostratotype of Kasimovian Stage (Afanasievo section, Moscow Basin, Russia)

The Afanasievo Quarry, approximately 90 km southeast of Moscow and about 5 km southwest of Voskresensk, starts with Late Moscovian limestone of the Peski Formation, which is overlain by shallow-water carbonates of the Krevyakinian Horizon (Substage) (Suvorovo and Voskresensk formations) and the lower part of the Khamovnikian Horizon (Substage) (Ratmirovo and Neverovo formations). These rocks were formed under the strong influence of glacio-eustatic sea-level fluctuations and are separated by the palaeosol horizons and minor stratigraphic gaps. The Moscovian–Kasimovian transition interval contains fusulinids, brachiopods, bryozoans, corals, and conodonts. It was recently proposed [Villa, E., Task Group, 2005. Report of the Task Group to establish GSSPs at the Moscovian–Kasimovian and Kasimovian-Gzhelian boundaries. Newsletter on Carboniferous Stratigraphy 23, 9–10] that the appearance of the conodont Idiognathodus sagittalis Kozitskaya is one of the best markers for definition of the base of the Kasimovian on the global chronostratigraphic scale. The first appearance of this species is 2 m above the base of Neverovo Formation, and is close to the first appearance of the fusulinid Montiparus in the section. The possible ancestor of I. sagittalis occurs in the lower Suvorovo Formation, but is more abundant and more advanced in the middle to upper parts of the Voskresensk Formation. This lineage has potential for defining a GSSP at the first appearance of I. sagittalis.     

Functional anatomy of fusulinids (foraminifera): Significance of the polar torsion illustrated inTriticites andSchwagerina (Schwagerinidae)

The phenomenon of polar torsion is described in the fusulinid generaTriticites andSchwagerina. It is known in elongate extinct and extant alveolinids, but never has been mentioned in fusulinids. In the latter, polar torsion occurs in ellipsoidal to cylindrical forms with folded septa in the polar region as well as throughout. In analogy to in situ observations on extant alveolinids, the functional significance of the polar torsion is proposed to be related to the distribution of septal pores and the special arrangement of septal folds in the polar region.     

New Pennsylvanian (Moscovian) crinoids from the Qijiagou Formation,Taoshigo Valley,Xinjiang Uyghur Autonomous Region,Western China

New collections and revision of previously collected Moscovian crinoids from the Qijiagou Formation of the Taoshigo Valley near Turpan, Xinjiang Uyghur Autonomous Region, Western China, add to the generic diversity of the fauna. This camerate-rich echinoderm fauna is now recognized as containing at least one blastoid, five camerate, and ten cladid crinoid genera. The fauna shows greatest affinity at the family level with Moscovian crinoid faunas of Japan and North America.New taxa proposed are: Rhepocatillocrinus tianshanensis n. gen. n. sp.; Binariacrinus alveus n. gen. n. sp.; Bassocrinus abyssus n. gen. n. sp.; and Brabeocrinus asiaensis n. sp.     

湖南慈利康家坪剖面二叠纪末类有孔虫的灭绝过程

湖南慈利地区二叠系-三叠系界线附近地层非常发育,是探讨二叠纪-三叠纪之交生态系转变的良好区域。本研究通过对该地区康家坪剖面长兴组上部与大冶组下部地层进行系统采样、切片研究,在长兴组上部地层中发现278个类有孔虫,共鉴定出4属11种(含2个未定种)。这些类有孔虫在地层中的分布表明类有孔虫在二叠纪末经历了一次突变式的灭绝过程,其灭绝层位位于长兴组顶部的生物碎屑灰岩与大冶组底部的微生物岩之交界线处。该研究不仅丰富了康家坪剖面在这一关键时期的生物群面貌,而且也为二叠纪末的生物灭绝事件的深入研究提供了新的材料。     

福建宁化上石炭统达拉阶的类

通过对福建宁化县泉下镇石灰窑下村上石炭统达拉阶类的系统研究,共描述类10属35种,包括3个未定种。根据类化石在地层中的分布和垂向变化规律,自上而下建立两个带、三个亚带:II.Fusulina Fusu linella带,3)Fusulinaquasicylindrica亚带,2)Beedeinamayiensis亚带和1)Fusulinellahelenae Pseudostaffella paradoxa亚带,I.Pseudoendothyraninghuaensis带。为该区以及我国石炭系地层的划分和对比提供重要的素材。     

Revised fusulinid biostratigraphy of the Middle–Late Permian of Jebel Tebaga (Tunisia)

Most carbonate series of Jebel Tebaga (Tunisia) are assigned to the Capitanian (last stage of the Middle Permian); however, their accurate correlation with the El Capitan stratotype in the USA and with contemporaneous Tethyan localities remains unclear. With the intent to establish more accurate lithostratigraphic and biostratigraphical divisions, (1) we re-sampled bed-by-bed the classical field sections of Jebel Tebaga; (2) we revised the lithostratigraphical units E-I to E-VI, and (3) we selected 9 fusulinids in order to characterize more precisely local bioevents. We have therefore studied 3 giant genera (Chusenella, Neoschwagerina and Yabeina), 3 medium-sized taxa (Dunbarula, Rauserella and Yangchienia), and 3 small size genera (Lantschichites, Codonofusiella and Reichelina). The first group was known to synchronously disappear at the time of the end-Guadalupian mass extinction. The thirth group was generally considered to be characteristic of the early Late Permian, after a Lilliput effect among the fusulinid groups, during which the dwarfs replaced the giants. Our data show that, in Jebel Tebaga, the so-called Wuchiapingian small forms Codonofusiella and Reichelina appear very early in the Late Capitanian. In some hills of the Tebaga area (i.e., Baten Beni Zid and Jebel Seikra), Codonofusiella and Reichelina even dominated the fusulinid assemblages during two short episodes. The first episode is located near the base of the Capitanian series; the second one, although located near its top, remains Capitanian in age, because it took place before the local disappearance of the three giants Neoschwagerina, Yabeina and Chusenella. As the sequence becomes sandier after this bioevent, the boundary with the Wuchiapingian (first stage of the Late Permian or Lopingian) cannot be well positioned. The end-Guadalupian event is only marked by this sedimentological modification. Because the Late Permian Cheguimi sandstone is entirely devoid of foraminifers and conodonts, no local subdivisions can be proposed in this series.