The First Discovery of Permian Conodont Fauna from Peri-Gondwana Cool Water Facies in Tibet, China

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Chinese Science Bulletin

The first discovery of Permian conodont fauna from peri-Gondwana cool water facies in Tibet, China

ZHENG YouYe1,2, XU RongKe1,3, WANG ChengYuan4† & MA GuoTao1

1 Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China; 2 Research Institute of Geological Survey of Tibet Autonomous Region, Lhasa 850000, China ; 3 Research Institute of Geological Survey of Gansu Province, Lanzhou 730050, China; 4 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China The Angjie Formation and Xiala Formation, present in the Shiquanhe area of Gar County in the western part of Gangdise, Tibet, belong to the Gangdise stratigraphic subregion. Conodonts have been found in the Angjie Formation, and they permit an age determination of Early to Middle Permian for that formation. The age of the Xiala Formation could be late Middle Permian. Whether the Late Permian marine deposits are present in this area still needs to be determined, but it is possible that the lower part of the Xiala Formation overlaps partly the upper part of the Angjie Formation. More importantly, the study has brought about a finding of typical peri-Gondwana cool water facies conodonts, namely, Vjalovognathus sp. nov. x. This is the first report and brief description of a conodont fauna from peri-Gondowana cool water facies in China. It indicates that the Gangdise stratigraphic subregion can be subdivided; the western part belongs to peri-Gondwana cool water facies, and the eastern part belongs to Tethys.

Gondwana, cool water facies, conodont fauna, Vjalovognathus, Gar County, Shiquan River, Tibet

Permian conodonts are reported herein from the Angjie it provides important biostratigraphic data for correlat- Formation in the Shiquanhe area, west Gangdise, Tibet. ing strata between Gondwana and Tethys and for inter- It has been debated whether Late Permian marine depos- preting the tectonic evolution of Tethys. its are present in this area. Most authors considered that there are no Late Permian marine deposits there[1―8]. 1 History of lithostratigraphy and chara- They assigned basically the Angjie Formation and Xiala cteristics of this area Formation to Early-Middle Permian. Changhsingian Late Paleozoic strata crop out in the Shiquanhe area, deposits were found at the type locality of the Jian- located within the Zuozuo fault uplift zone (possibly zhanong Formation in Geize County, but those are non- equivalent to the western part of the Longger fault uplift marine deposits[1,9]. There are no Late Permian marine zone) between the Gangdise volcanic-magmatic arc and deposits dated by conodonts in the Shiquanhe area of Shiquanhe-Sainza-Jiali suture zone. Guo et al.[13] divided Gar County. In recent years, some outcrops of the Jian- the strata, in ascending order, into the Naziduopo, Yang- zhanong Formation have been found in the Geize area, weishan, and Zuozuo formations. The Naziduopo and those strata all have been dated back to the Middle

[10―12]

Permian . Received June 1, 2006; accepted January 25, 2007 GEOLOGY The finding of Permian conodonts in the Shiquanhe doi: 10.1007/s11434-007-0168-2 †Corresponding author (email: [email protected]) area, Tibet is very helpful to dating the age of the Angjie Supported by the Chinese National Key Project for Basic Research (Grant No. Formation. More important is the discovery of Permian 2002CB412610), the National Natural Science Foundation of China (Grant Nos. 40542008 and 40672012) and Chinese Geological Survey Project (Grant No. cool water conodonts of this part of peri-Gondwana, as 200213000009)

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Formation consists of sandstone in the lower part and will be published in another paper). clastic limestone and black slate in the upper part; its base is not exposed, and there is no fossil record from 2 The locations of the sections and de- this formation, but it was dated as Early Permian ac- scription cording to regional correlation.The Yangweishan For- mation consists of bioclastic limestone and micrite, 2.1 The Langjiu Power Station section in Gar yielding corals, brachiopods, foraminifers, bryozoans, County bivalves, fusulinids and some other fossils. It was dated This section is located in the western part of Zuozuo [13,14] as late Chihsian Stage of the Early Permian . The Township, about 20 km east of Shiquanhe Town, in Gar Zuozuo Formation, composed of a suite of dolomites, County, Tibet (section 1 in Figure 1). The section begins contains no reported fossil record. It was considered to from the Langjiu Power Station (80°20′5E, 32°23′58″N), [14] be Late Permian . The Bureau of Geology and Mineral and terminates near Tangnale (80°21′28″E, 32°29′38″N); Resources of Tibet Autonomous Region has abolished it is about 10 km long, in which the succession of the these three formation names mentioned above, and has Permian system is as follows (Figure 2): assigned the lower part of the Naziduopo Formation to the Carboniferous Laga Formation and the upper part to the Late Carboniferous-Early Permian Angjie Formation. The Yangweishan Formation was considered to be equivalent to the Xiala Formation, but maybe a little higher than this Formation; its lower limit could be middle-late Early Permian, but it could extend up to Late Permian (the Permian System was treated as two-fold at that time). The upper limit of the Xiala Formation is not younger than the Maokouan Stage. The Zuozuo Forma- tion was considered to be equivalent to the basal part of the Jipuri’a Formation (with adoption of a three-fold Permian System, its upper limit is not younger than the end of the Middle Permian.)[10]. The Chengdu Geology and Mineral Resources Institute (2002) adopted a three-fold Permian and assigned the Laga Formation, Angjie Formation and Xiala Formations to the Late Carboniferous to Early Permian, Early Permian and Middle Permian, respectively (The Southwest Pro- Figure 1 The location of the sections. gramm Office of Geologiccal Survey Bureau of China: Stratigraphic Subdivision and Correlation of the Qing- Overlying strata: Early Triassic Tangnale Formation consists of hai-Xizang Plauteau (unpublished)). sand-and pebble- sized intraclastic dolomite and massive dolo- The definition of the Laga, Angjie, and Xiala forma- mite, yielding conodonts: Pachycladina obliqua Staesche 1964, Pachycladina cf. tridentata Z. H Wang et Cao 1981; tions in present paper adapted the point of views in the Pachycladina spp., Neohindeodella triassica Müller, 1956: Stratigraphy (lithostratigraphic) of the Tibet Auto- Cornudina sp., Hadrodontina sp., Hibbardella sp. etc. monous Region compiled by Bureau of Geology and ------Parallel unconformity------Mineral Resources of Tibet Autonomous Region, but the Xiala Formation Px) 733.44 m first two authors of the present paper have found that the 14. Gray-black, massive silty micrite 180.48 m Zuozuo Formation is quite different from the Jipuri’a 13. Gray, massive silty siliceous limestone 175.61 m Formation in lithological characters and biota. Also, be- 12. Gray, massive silty siliceous limestone intercalated with purple thick siliceous rocks 134.97 m cause Triassic conodonts have been found from the 11. Dark gray, massive siliceous calcilutite intercalated with gray- Zuozuo Formation, the first two authors of the present white silty sparite 64.12 m paper have named a new unit called the Tangnale For- 10. Dark gray, massive siliceous calcilutite 11.80 m mation instead of previously Zuozuo Formation (This 9. Gray, massive silty calcilutite 88.28 m

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ARTICLES ARTICLES

Figure 2 The Langjiu Power Station Permian section and the positions of samples. Er, Rigongla Formation; Td, Tangnale Formation; Px, Xiala Formation; Pa, Angjie Formation; HS-36, Sample positions and numbers.

8. Dark gray, medium-thin bedded bioclastic siliceous limestone 14. Grayish, medium- to thin-bedded fine-grained- calcirudite in- intercalated with calcareous sandstone, yielding brachiopods, tercalated with yellow brown sandy slate crinoid stems, and bryozoans 23.69 m 59.00 m 7. Dark gray, massive siliceous limestone alternated with thin- 13. Gray, medium- to thin- bedded grain-caorse sparite, yielding bedded siliceous limestone 8.53 m conodonts in sample HS-64: Mesogondolella sp.nov., Meso- 6. Dark gray, purple, medium- to thin-bedded bioclastic siliceous gondolella sp. 22.61 m limestone yielding brachiopods and crinoid stems 45.96 m Underlying strata: Laga Formation: Medium- to thick-bedded ------Conformity------fine-grained quartz sandstone intercalated with gray-green Angjie Formation (Pa) > 215.77 m thin-bedded shale. 5. Dark gray, medium- to thin -bedded silty calcilutite 36.99 m 4. Gray, medium-bedded bioclastic calcilutite intercalated with thin- bedded silty limestone, yielding foraminifers, brachipods, and crinoid stem fragments 16.77 m 3. Dark gray, medium-bedded micrite intercalated with thick- bedded silty limestone, yielding brachiopods, ostracods, crinoid stems, and algae fragments. Sample HS-40 (Coordinate: 80°22′1″E, 32°2′31″N) yields conodonts: Mesogondolella cf. stampflii, Pb element of gondolellids,

Pa element of gondolellids, 4.78 m 2. Brown-yellow, medium-thin bedded coarse-grained-calcareous Figure 3 Section of the Permian and sampling location at Yangwei sandstone, yielding brachiopods and bryozoans. 4.78 m Mountain. 1. Thick-bedded bioclastic micrite (bottom not exposed). Samples HS―41, 43 yield abundant algae, corals, brachiopods, bryo- 3 Geologic ages of the Angjie Formation zoans, crinoid stems, and foraminifers. and Xiala Formation Sample HS ― 44 (80°20′57″E, 32°23′59″N) yields conodonts: Vjalovognathus new sp. x, Hindeodus sp. Pa The Angjie Formation was named in 1980 by the Ti- element, Pb element of gondolellids, M element of gondolellids >152.45 m betan comprehensive geologic team, and it was assigned to the Late Carboniferous. Jin et al.[1] assigned the Ang- 2.2 Yangweishan section jie Formation to the Early Permian. This formation con- This section is located at the Yangwei Mountain, 1 km tains brachiopods: Neospirifer, Spiriferina, Marginifera, east of Shiquanhe Town (section 2 in Figure 1). The be- Cancrinella; Bryozoans: Fenestella, Ramiporidra, Stre- ginning position: 80°08′30″E, 32°30′59″N, terminal po- blascopora, Stenopora, Pamirella, Dyscritella; Ostracods: sition: 80°21′28″E, 32°29′38″N, about 8 km long, in Bairdia, Aparchites, Cytherellina, Orthonaria, Recto- which we describe a member as follows (Figure 3): bairdia, etc. Wang Y J dated this formation as the Overlying strata: The Xiala Formation: gray, medium-to thin- Longlinian Stage of the Chuanshanian[1], but this is an

bedded coarse-grained sandy sparite intercalated with dark abolished chronological unit. The Chuanshan Formation GEOLOGY gray siliceous striped limestone yields conodonts. Sweetognathus whitei, occurring in the ------Conformity------Angjie Formation (Pa) Early Permian Artinskian, has been found from the up- 15. Gray-brown, medium- to thin-bedded sandy limestone alterna- per part of the Chuanshan Formation at its type local- ted with soil-yellow, thin-bedded shale 23.91 m ity[15]. The Angjie Formation should be assigned to

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Early-Middle Permian. The sample HS44 from the Ang- Formation, we cannot exclude the possibility that Late jie Formation yields Vjalovognathus sp. nov. x in very Permian could be present in this area. good preservation. Vjalovognathus sp. nov. x could be To sum up, the age of the Angjie Formation is from evolved from Vjalovognathus australis. The range of the Early Permian Kungurian to Middle Permian Capitanian, latter is late Sakmarian to early Artinskian[16]. The range and the lower part of the Xiala Formation overlaps of Vjalovognathus sp. nov. x could be no later than partly the upper part of the Angjie Formation, still be- Kungurian, or even earlier (Nicoll, personal communi- longing to the Middle Permian. The age of the upper cation). Sample HS40 contains Mesogondolella cf. part of the Xiala Formation is uncertain; we cannot ex- stampflli Kozur[17]; M. stampflli is very similar to clude the possiblity that the Xiala Formation could be Mesogondolella shannoni Wardlaw; the range of the partly assignable to the Late Permian. But in Late Per- latter is Middle Permian early Capitanian, and the for- mian in vast area of south Tibet there are nonmarine de- mer is Capitanian; however, the present specimen is not posits of the Gondwanaland[1―8,19]. complete-the outer anterior margin is broken. Kozur It is very possible, based on lithological characteris- (personal communication) considers that it is Mesogon- tics, that more conodont horizons could be found in the dolella stampflli. The authors identified it as Mesogon- Angjie and Xiala formations. This would be very im- dolella cf. stampflli; the age could be early Capitanian. portant for better dating of the Angjie and Xiala forma- Thus, the age of the Angjie Formation should be from tions, and also important for establishing the conodont Kungurian to Capitanian. sequence in this area. More detailed work needs to be Many fossils have been found from the Xiala Forma- done. tion in this area, such as fusulinids (Schubertella sp.), foraminifers (Baisalina guizhouensis Wang, Cribro- 4 The discovery of conodont fauna from generina sp., Tetrataxis sp.), bryozoans (Fenestella sp., the peri-Gondwana cool water facies Penniretepora sp.), and aboundant brachiopods, corals, and bivalves[13,14]. Most authors assigned the Xiala For- (1) The first report of peri-Gondwanan cool water fa- mation to the late Middle Permian. Conodonts (Meso- cies conodonts, namely, Vjalovognathus sp. nov. x, from gondolella sp. nov., Mesogondolella sp.) are found from the Angjie Formation in Tibet. Prof. Wang Zhihao the Angjie Formation of the Yangweishan section (personal communication) told the corresponding author (HS64). Mesogondolella sp. nov. is a new species found of the present paper that Dr. Kozur had found one in Oman area described by Kozur and Wardlaw (per- specimen of Vjalovognathus from Selong section of Ti- sonal communication) . The corresponding author of the bet, when he visited the Nanjing institute but this speci- present paper considers that this new species evolves men was lost and not published. The present paper is the from Mesogondolella idahoensis (Youngquist, Hawley first report and description of peri-Gondwana conodonts et Miller); the range of the latter is Early Permian, late from the Permian cool water facies in China. Kungurian, to Middle Permian, Roadian. The unde- (2) Comparison of the western Gangdise conodont scribed new species occurs from the upper Wordian up facies with the so-called cool water facies fauna of to the upper, but not uppermost Capitanian. We have not western Yunnan. Conodonts were found from the found conodonts from the Xiala Formation. The strata Dingjiazhai and Woniusi Formations in the Baoshan [20,21] bearing conodonts at the Yangweishan section possibly block in western Yunnan , and based on conodonts, overlaps partly strata bearing conodonts of the Langjiu the Dingjiazhai Formation is dated as late Sakmarian, Power Station section, having the same age. We have no and the Woniusi Formation is early Artinskian. The reason to conclude that the strata of the Yangweishan conodonts from the Dingjiazhai Formation were consid- [22] section are older than the one of the Langjiu Power Sta- ered to be cool water facies fauna , but most authors [20,21] tion. The lower part of the Xiala Formation could be late suggest that it is a cool-warm mixed fauna ; cono- Middle Permian in age. Xia et al.[18] have pointed out donts from the intercalated limestone in the basalts of that the top of the Xiala Formation at its type locality the Woniusi Formation are very similar to those of and the top of the Angjie Formation at Shuizhu area are America. According to Early Permian palaeogeographi- equal; both cannot be distinguished. Because there are cal reconstruction[23,24], those two localities were located still no fossils recorded from the upper part of the Xiala at 10°―15°S, belonging to tropical or temperate fauna,

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and the Baoshan block was situated within Tethys realm. tolerant to cool temperate conditions which allowed it to

The timing of displacement of the Baoshan block from invade the immediate postglacial marine environment of ARTICLES peri-Gondwana was in the Artinskian, indicated by the peri-Gondwana[16]. eruptive basalts of the Woniusi Formation, and moved The finding of the cool water facies in the Shiquanhe northward[21]. area gives rise to a problem: this area might not belong The Angjie Formation in the Shiquanhe area of Tibet to Gangdise (Sainza-Shiquanhe) stratigraphic subregion yields Vjalovognathus sp.nov. x; this genus is a typical as previously thought. In the Sainza area, the cool water cool water facies conodont fauna in the peri-Gond- facies has never been found; the distance from Shi- wana[16]. Most localities having Vjalovognathus are at quanhe to Sainza is about 800 km. It is possible that the Southern Hemisphere paleo-latitudes of around 50°, less western part of Gangdise (Shiquanhe area) belongs to in between 45° and 60°, being a high latitude[16]. Vjalo- the peri-Gondwana cool water facies, but the Eastern vognathus has never been found in the Baoshan block in part (Shainza) belongs to Tethys. western Yunnan[21]. Conodonts from the Angjie Formation of the Shiquanhe area in Tibet are different from the ones 5 Systematic palaeontology――Taxonomic of the Baoshan block in western Yunnan. The former be- notes longs to peri-Gondwana cool water faces, the latter belongs to paleo-Tethys mixed fauna, or temperate fauna. 5.1 Genus Vjalovognathus (Kozur, 1977) (3) Distribution and ecology of the genus Vjalovog- Type species Vjalovites shindyensis Kozur, 1976 [16] nathus. Based on Nicoll’s report , “Biogeo- Revised diagnosis (see Nicoll and Metcalfe, 1998, pp. graphically, Vjalovognathus appears to be restricted to 435―436[16]) the northern margin of eastern Gondwanaland and may Remarks: Vjalovognathus appears to be restricted to help to define an Earstern Gondwanaland Conodont [25] the north margin of eastern Gondwanaland and may help Province as provisionally suggested by Kozur ”. to define an Eastern Gondwanaland Conodont Province Specimens of the genus Vjalovognathus have been re- as provisionally suggested by Kozur[16]. It is suggested [26,27] ported from the Pamirs , the salt Range of Paki- that Vjalovognathus may have been tolerant to cool [28] [29] [16] stan , Timor , Western Australia and the Selong temperate conditions[16]. The Pa element of Vjalovog- section of Tibet (Wang, personal communication). The nathus is deeply excavated, with a thin-walled crown Sakmarian-early Artinskian species Vjalovognathus structure easily broken. All specimens Nicoll & Met- australis is known from the Carnarvan Basin, Timor, calfe (1998) studied are incomplete, but the specimens [16] and the Pamirs . The Kungurian species, V. s h i n d y e n - from the Shiquanhe area in Tibet are complete. The sis is known from the Canning and southern Carnarvon identification of Vjalovognathus is based mainly on the [16,26] Basins and the Pamirs . The Roadian species, Vja- Pa element, especially the characters of the denticles, in lovognathus sp. nov. A Nicoll et Metcalfe, 1998’ is which the cross-section of the denticle is most important. [16] known only from the Southern Carnavon Basin , and Nicoll & Metcalfe[16] considered that Gondolella postde- the undescribed Changhsingian species is known only nuda von Bitter & Merril, 1980, is a possible direct an- from the Salt Range of Pakistan[16]. cestor of Vjalovognathus, not as Kozur[26] suggested that All of these Vjalovognathus localities were located at Vjalovognathus evolved from Neostreptognathodus, 40°S palaeolatitudes and in basins on shelves or adjacent probably N. peguopensis or a similar form. Nicoll (per- to the Palao-Tethys or Meso-Tethys Oceans[16], except sonal communication) announced that they already de- for two of van der Boogaard’s Timor localities and one scribed 7 species for the genus Vjalovognathus, but their Canning basin sample[16,29]. Vjalovognathus elements paper has not yet been published. Three species, i.e. occur in low abundance (less than 10 specimens per Vjalovognathus shindyensis (Kozur), V. australis Nicoll sample) and conodont faunal diversity is generally low et Metcalfe, 1998, and V. sp. nov. A Nicoll & Metcalfe, (less than five species). Only in the two northernmost 1998, have been described[16]. GEOLOGY localities of Timor and the Pamir are more than five Age: The age of this genus is limited to Permian, species present in any given sample[16]. mainly in Early and Middle Permian. A Late Permian It is suggested that Vjalovognathus may have been species Wardlaw found in the Salt Range of Pakistan has

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not yet been formally reported[16]. is differentiated into ‘blade’ and ‘platform’ at the point 5.2 Vjalovognathus sp. nov. x (Figure 4-9―12) where the basal margin of the element flares abruptly outward. A single truncated denticle row extends from Diagnosis and description: (Pa element) The Pa anterior ‘blade’ to posterior cusp, having up to 12 denti- element is segminiscaphate, consisting of two parts: an- cles. The ‘blade’ supports 4―6 denticles, the ‘platform’ terior ‘free blade’ and posterior ‘platform’. The element also has 4 to 6 denticles. The above view shows that the truncated denticle row does not become appreciably wider on the “platform,” but the basal margin flares outward giving the appearance of a ‘platform’ Denticle cross section round to ovate, denticles discrete, the diameters of the denticles on the “platform” are nearly the same, the spaces between the two denticles are also nearly the same. The diameters of the denticles of the nearest cusp and of anterior 3－4 denticles are relatively small,and the spacing of anterior denticles gradually extends anteriorly. Many specimens show a slight de- pression in the central part of the denticle. The cusp is located at the posterior end of the unit, long, and pointed, projecting posteriorly. The cusp and posteriormost dencti- cle are twisted slightly inward. The element is deeply excavated under the ‘platform’ but under the ‘blade’ is relatively shallowly excavated. Remarks: Nicoll (personal communication) announced that Nicoll, Wardlaw, and Metcalfe would jointly publish a paper in which they will describe 7 species of genus Vjalovognathus. Vjalovognathus sp. nov. x described in the present paper is similar to V. sp. nov. A Nicoll et Metcalfe 1998, but the latter has been formally named by Nicoll et al (personal communication). To avoid duplication, our specimens are not formally named for the time being. Vjalovognathus sp. nov. x differs mainly from V. s h i nd y e n s i s , V. a u s t r a l i s , and V. sp. nov. A in its denticle having round to axial-ovate Figure 4 1, A Pb element of gondolellid conodont, lateral view, ×120, cross-section, and in having a relatively thick-walled rep. no: 7011, Langjiu Power Station, Bed 3 (HS-40); 2, ?Hindeodus sp., Pa element lateral view, ×144, rep. no: 7012, Langjiu Power Station, Bed crown structure; the elements are complete. V. australis 3 (HS-40); 3, Hindeodus sp., lateral view, ×144, rep. no: 7006, Langjiu has round to ovate denticles that are discrete, with a Power Station, Bed 1 (HS-44); 4, a Pb element of gondolellid conodont. ×90, rep. no: 7004, Langjiu Power Station, Bed 1 (HS-44); 5, an M ele- shallow anterior groove and very thin-walled basal cav- ment of gondolellid conodont, lateral view, ×120, rep. no: 7005, Langjiu ity, easily broken, but V. sp. nov. x has denticles with no Power Station, Bed 1 (HS-44); 6, Hindeodus sp., Sc element, ×132, rep. no: 7029, Langjiu Power Station, Bed 1 (HS-44); 7, Mesogondolella cf. shallow and narrow anterior groove. V. shindyensis has stampflii Kozur, 2002, oral view, ×108, rep. nos: 7009 and 7010, Langjiu denticles with cross-section ovate to kidney-bean shaped Power Station, Bed 3 (HS-40); 8, Mesogondolella sp. nov., oral view, ×48, rep. no: 7003, Yangweishan section, Bed 13 (HS-64); 9―12, Vjalovog- and linearly compressed at base, with anterior wide nathus sp. nov. X, 9: ×120, lateral view, rep. no: 7007, Langjiu Power groove. Nicoll (personal communication) considers that Station, Bed 1 (HS-44); 10: ×90, lateral view, rep. no: 7008, Langjiu Power Station, Bed 1(HS-44); 11: ×240, oral view, partly enlarged 10, V. sp. nov. x is much closer to V. sp. nov. A Nicoll et Langjiu Power Station, Bed 1(HS-44);12: ×120, lateral view, rep. no: 7028, Metcalfe, 1998, but the latter has denticles with an ovate Langjiu Power Station section, Bed 1 (HS-44); 13―14, Mesogondolella to diamond-shaped cross-section, a prominent axial sp., oral views;13: ×78, rep. no: 7001,Yangweishan section, Bed 13 (HS-64);14: ×90, rep. no: 7002, Yangweishan section, Bed 13(HS-64). All ridge running a long axial crest of the element, and a specimens are housed in Faculty of Stratigraphy and Paleontology of short, rounded and posteriorly inclined cusp. China University of Geosciences, Wuhan. Age range: The age of Vjalovognathus sp. nov. x is

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difficult to determine. Nicoll (2006, personal communi- Langjiu Power Station in Gar County, west Tibet.

cation) considered that it is no later than Kungurian, or ARTICLES The corresponding author is indebted to Drs. Bob Nicoll and H. Kozur for even earlier, but this is merely a “best guess.” The range their help. Dr. Kozur kindly provided the age of their undescribed species of this species could be from Kungurian to late Middle Mesogondolella sp. nov.; Dr. Nicoll gave an affirmative answer to our Permian. identification of genus Vjalovognathus, “definitely, with no reserva- tion”(personal communication).The authors are greatly indepted to Dr. Stratigraphic recovery: Present specimens were John Repetski and Prof. R J Aldridge for critically reading the manuscript collected from the Permian Angjie Formation of the and valuable comments.

1 Jin Y G, Shang Q H, Hou Q P, et al. Permian System. Stratigraphy Beijing: Geological Publishing House, 1987. 98―161 Dictionary of China (in Chinese). Beijing: Geological Publishing 15 Wang C Y, ed. Conodonts of Lower Yangtze Valley―An Index to House, 2000. 34―64 Biostratigraphy and Organic Metamorphic Maturity (in Chinese). 2 Bureau of Geology and Mineral Resources of Xizang Autonomous Beijing: Science Press, 1993. 1―326 Region, ed. Permian. In: Regional Geology of Xizang (Tibet) 16 Nicoll R S, Metcalfe I. Early and Middle Permian Conodonts from Autonomous Region. People’s Republic of China, Ministry of Geol- the Canning and Southern Carnarvon Basins, Western Australia: their ogy and Mineral Resources Geological Memoirs (in Chinese). Series implications for regional biogeography and palaeoclimatology. Proc 1, No. 31. Beijing: Geological Publishing House, 1993. 103―136 Roy Soc Victoria, 1998, 110: 419―461 3 Petroleum Geology of Qinghai-Xizang Compiler Group. The Hy- 17 Kozur H. Definition of the Loping base with the FAD of Clarkina drocarbon regions of Qinghai and Xizang. Petrol Geol China (in postbitteri postbitteri. Permophiles, 2002, 41: 41―50 Chinese), 1990, 14: 1―483 18 Xia F S, Zhang B G, Sun D L, et al. Carboniferous and Permian. In: 4 Guo T Y, Liang D Y, Zhang Y Z, et al. A preliminary approach to the S. Special Papers on the Strata and Fossils from Xainza and Baingoin, Tibet Late Early Hercynian Movement and its geological significance. Xizang, part 1. Bulletin of Nanjing Institute of Geology and Palae- Contribution to the Geology of the Qinghai-Xizang (Tibet) Plateau, No. ontology, Academic Sinica, Vol 10 (in Chinese). Nanjing: Jiangsu 1 (in Chinese). Beijing: Geological Publishing House, 1982. 96―103 Science and Technology Publishing House 1986. 32―45 5 Luo Z S. The Plate Tectonic and Plate-Tectonic development model 19 Huang J Q, Chen B W. The Evolution of the Tethys in China and Ad- for the Qinghai-Xizang Plateau. Contribution to the Geology of the jacent Regions. Beijing: Geological Publishing House, 1987. 1―78 Qinghai-Xizang (Tibet) Plateau, Vol 1 (in Chinese). Beijing: Geo- 20 Wang X D, T. Sugiyama, K. Uyeno, et al. Carboniferous and Per- logical Publishing House, 1982. 139―153 mian zoogeographical change of the Baoshan Block, southwest 6 Liu Z Q, Pan G T, Zheng H X, et al. A Preliminary study on the China. Acta Palaeont Sin (in Chinese), 2000, 39(4): 493―506 North boundary and the evolution of Gondwana and Tethys in light 21 Wang W, Dong Z Z, Wang C Y. The Conodont ages of the Dingjia- of the new data on Qinghai-Xizang (Tibet) Plateau. Contribution to zhai and Woniusi Formations in the Baoshan area, western Yunnan. the Geology of the Qinghai-Xizang (Tibet) Plateau, Vol 12 (in Chi- Acta Micropalaeont Sin (in Chinese), 2004, 21(3): 273―282 nese). Beijing: Geological Publishing House, 1983. 11―24 22 Nie Z T, Song Z M, Jiang J Y, et al. Biota features of the Gondwana 7 Liu Z Q, Jiang C F, Liu B T, et al. New thoughts on the Geology of affinity facies and review of their stratigraphic ages in the western Tethys-Himalayan tectonic domain. Contribution to the Geology of Yunnan. Geosci―J Graduate School (in Chinese), 1993, 7(4): the Qinghai-Xizang (Tibet) Plateau, Vol 15 (in Chinese). Beijing: 384―391 Geological Publishing House, 1984. 131―146 23 Ziegler A M. Paleozoic biogeography and climatology. In: Niklas K J, 8 Zhao Z Z, Li Y T, Ye H F, et al. Tectonic characters of the Qing- ed. Paleontology, Paleoecology and Evolution. No. 2. New York: hai-Xizang (Tibet) Plateau and Basinal Evolution (in Chinese). Bei- Praeger, 1981. 231―266 jing: Science Press, 2001. 15―17 24 Xu G R, Yang W P. Permian. In: Yin H F, et al. eds. Paleobiogeogra- 9 Jiang Z T, Xu Z Y. Geological significance of the Cathayana Flora phy of China (in Chinese). Wuhan: China University of Geosciences from the Xiagangjian and other places, in Tibet. Geol China (in Chi- Press, 1988. 176―195 nese), 1983, 2: 4 25 Kozur H. Preliminary report on the Permian conodont faunas of 10 Bureau of Geology and Mineral Resources of Xizang Autonomous Darvas ans SE Pamir and its importance for the Permian timescales. Region, ed. Stratigraphy (Lithostratigraphic) of Xizang Autonomous Permophiles, 1994, 24: 13―15 Region (in Chinese). Wuhan: China University of Geosciences Press, 26 Kozur H, Mostler H. Neue Conodonten aus dem Jungpaläozoikum 1997. 148―149 und der Trias. Geologische Palaontologische Mitteilungen Innsbruck, 11 Shi H, Tao X F, Liu D Z, et al. New materials and futher understand- 1976, 6: 1―33 ing of fossil plants in the Jianzhalong Formation, Tibet. Geol Bull 27 Reimers A N. Lower Permian conodonts of Permian and Darvaz. China (in Chinese), 2002, 21(7): 428―430 Bull Moscow Soc Naturalists, Geol Ser, 1991, 66: 59―72 12 Zhou Y Y, Jiang Y S, Wang M G. Permian Debuco Formation in the 28 Wardlaw B R, Pogue K R. The Permian of Pakistan. In: Scholle P A, Coqen-Xainza stratigraphic area, Tibet. Geol Bull China (in Chinese), Peryt T M, Ulmer-Scholle D S, eds. The Permian of Northern Pangea. 2002, 21(2): 79―82 Vol 2, Sedimentary Basins and Economic Resources. Berlin:

13 Guo T Y, Liang D Y, Zhang Y Z, et al. Geology of Ngari Tibet (Xi- Springer-Verlag, 1995. 215―224 GEOLOGY zang) (in Chinese). Wuhan: China University of Geosciences Press, 29 Van den Boogaard M. Lower Permian conodonts from western Timor 1991. 37―43 (Indonesia). In: Proceeding of the Koninklijke Nederlandse Akademie 14 Regional Geological Surveying Team of Bureau of Geology and van Westenschappen, Ser B, Palaeontology, Geology, Physics, Mineral Resources of Tibet (Xizang) Autonomous Region. Regional Chemistry, Antropology. Amsterdam-Oxford-New York: North- Geological Report of 1:1000000 Ritu Geological Map (in Chinese). Holland, 1987. 15―39

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