brachiopod fauna of the shashishan formation (mid ...museum.wa.gov.au/sites/default/files/3. chen,...

Records of the Western Australian MUSCllm Supplement No. 58: 37-57 (2000).

Brachiopod fauna of the Shashishan Formation (mid Famennian)in Kruktag, South Tianshan

Xiu-Qin Chen and Han-Kui Xu

Nanjing Institute of Geology and Palaeontology, Academia Sinica,39 East Beijing Road, Nanjing 210008, China.

Abstract Brachiopods described herein are from a section in the ShashishanFormation, Kruktag, South Tianshan, as resurrected herein based on lithologicand brachiopod correlation. It is proposed that the Shashishan Formationpossibly underlies the Pochengzi Formation. Ten brachiopod genera (7species, 2 of them new, and 4 indeterminate species) are represented:Productella sllbovata sp. nov., Prodllctellana cf. linglingensis Wang, ?Spinlllicostaxinjiangensis Zhang, ?Avonia sp., Scllllehertella sp., Ptyehomaletoeehia sp.,Nayllnnella synplicata (Grabau), N. abrllpta (Grabau), Athyris retielllata sp. nov.,Cyrtospirifer sp., Tentieospirifer cf. gortani (pillizzari). The fauna, named theNaYllllnella (=Yllllnanella Grabau 1931) fauna and its correlation with the faunafrom Xikuangshan Formation, provides evidence that the age of theShashishan Formation is Middle Famennian.

INTRODUCTION

On the basis of brachiopods, the age of thePochengzi Formation and Shashishan Formation inSouth Tianshan (Figure 1) have long beenconsidered to be Late Devonian in age. ThePochengzi Formation, erected in 1958 by theThirteenth Team of the Ministry of Geology wasoriginally thought to be composed of about 2620 mof acid and mid-acid volcanics with some lenses ofbedded limestone. In 1965 (on the K-45-XXIIIGeological Map and accompanying explanatorynotes), the Late Devonian deposits in Kruktagregion were named the Kizirtag Formation ratherthan the Pochengzi Formation and ShashishanFormation. Subsequently, Zeng and Xiao found thename Kizirtag Formation was occupied having beenused in Kelpin region. Zeng and Xiao (1979) andThe Compiling Group of the Regional StratigraphicChart of Xinjiang, Uygar Autonomous Region(1981) [referred to hereafter as the RSCX 1981]therefore reverted to the name, PochengziFormation for the Late Devonian sequences in theKruktag region and considered it be composed ofthree subformations:• the upper part occurring on the north slope of

the Karatag (Figure 2), the south slope ofKizirtag (Figure 2) and Pochengzi, composedof quartz porphyry, tufflava, tuff breccia,tuffstone and siltstone bedded with rarelimestones from which Camarotoechiashetienqiaoensis, C. livoniciformis, Anastrophia sp.and Cyrtospirifer sp. were recovered.

• the middle part occurring in western Karatag,the eastern extremity of Kizirtag, east and west

of Pochengzi. It is comprised principally ofpurple tuffstone, bedded tufflava, tuff brecciaand limestone in western Karatag andlimestone, argillaceous limestone, bedded shaleand sandstone in the eastern extremity ofKizirtag, the latter being about 500 m inthickness. In the areas east and west ofPochengzi, it is composed of about 700 m ofclastics from which Yunnanella sp., Atrypagurdoni and Schuchertella sp. have beenrecovered. Besides these deposits, the depositsof the Shashishan Formation were includedwith this part.

• the lower part occurring in a depression insouthern Kizirtag consists of light purple, greyand green quartz porphyry, tufflava, tuffbreccia, sandstone intercalated with thinlimestone; no fossils have been reported fromthis part of the formation.

As these three parts, or subformations, have notbeen found in the one section, problems have arisenin recognizing them in the field.

The stratotype of the Shashishan Formation,erected by Zhang et al. (1959), comprised principallyof carbonates, is a comparatively complete section,rich in fossils. This section was assigned a Frasnianage (Zhang et al. 1959). But this age determinationwas abandoned in 1965 on the K-45-XXIIIGeological Map and in the accompanyingexplanatory notes.

Through restudy of the brachiopod faunacollected from a section the Shashishan Formation(Figure 1) by Zhang and colleagues in 1957, andlater published (Zhang et al. 1959), a mid

38 Xiu-Qin Chen, Han-Kui Xu

.'

Location

Figure 1 Location of area showing the locality of theShashishan section.

sandstone, mudstone and limestone lens, fromwhich some brachiopods have been found in theupper and middle parts of the formation, theShashishan Formation is composed of rather thicklimestones with argillaceous limestone intercalatedwith shale and sandstone (about 695 m) bearingabundant brachiopods of the Nayzmnella Fauna, afauna quite unlike that of the Pochengzi Formation.Because of these differences, Xu and Chen (1999),suggested that the Shashishan Formation shouldnot be abandoned as a rock-stratigraphic unit as hasrecently occurred, for example, Zhou and Chen(1990) described the sediments of the 695 m sectionbut referred to it as the Pochengzi Formation ratherthan the Shashishan Formation. This re-examinationof the brachiopods from the section in questionadds weight to the proposal that the ShashishanFormation should be retained.

Although the sedimentary environment of theShashishan Formation is similar to that of theXikuangshan Formation in Hunan, South China andthe Hongguleleng Formation in the west JunggarBasin, Northern Xinjiang, presentpalaeobiogeographical investigations indicate thatduring the Devonian South Tianshan and SouthChina belonged to the one province while theJunggar Basin belonged to a separate province, theNorth China Block.

BIOSTRATIGRAPHY

with AthyrisCyrtospirifer

7.0m

28.5 m5.0m5.0m5.0m

6.

12.11.10.9.

The Shashishan section, located about 48 kmnortheast of Pochengzi (Figures 1, 2) wasmeasured through the Shashishan Formation thatis faulted against the Jurassic at the base and withJurassic horizons lying unconformably above thesequence. It is composed of about 695 m oflimestone, argillaceous limestone, bedded shaleand sandstone (Figure 3). Shelly faunas aredominated by brachiopods with a fewcephalopods and bryozoans. The sequence of LateDevonian intervals sampled for brachiopod faunasis as follows:Jurassic[Unconformity]13. 78.5 m dark grey limestone

reticula ta (SKP020),sp.(SKPOI9)dark grey limestoneargillaceous limestoneyellow calcareous sandstoneshales with bedded nodularlimestone

8. 13.6 m light grey limestone7. 10.2 m dark grey limestone bedded shale

with Nayunnella synplicata, Athyrisreticulata (SKPOI8)yellow-green shale with Nayzmnella

Famennian age can be assigned to the Formationand, based on lithologic and brachiopod correlation,we now consider it to be an independent formationunderlying the Pochengzi Formation. While thePochengzi Formation consists of very thickvolcaniclastics (about 2620) intercalated with rare

Figure 2 Locality map showing location of areasreferred to in the text.

Famennian brachiopod fauna from South Tianshan, China 39

67.8

Conglomerate, sandstone and shale with thin coal beds

13. Dark grey limestone with A/hyris reticula/a, CYr/ospirijer sp. (SKP020, SKP019)

12. Dark grey limestone

11. Argillaceous limestone

10. Yellow calcareous sandstone

9. Shale bedded nodular limestone

8. light grey limestone

7. Dark grey limestone and bedded shale with Nayunne/la synplica/a. A/hyris reticulata (SKP018)

6. Yellow and green shale with Nayunnel/a synplica/a, N abrup/a. A/hyris re/icula/aTen/ieaspirijercf. gOr/ani (SKP017, SKP016)

5. Dark grey limestone

Argillaceous limestone

Sandy shale and thin bedded limestone

20kmI

oI

Brown shale

Argillaceous limestone

Shale bedded nodular limestone with Productel/a subova/a sp. noy., Nayunnellasynp/icata .Ten/icospirijer cf. gOr/ani (SKP014· SKP012)

Yellow and green shale bedded nodular limestone with Nayunnel/a synp/ica/a. N. abrupta,Athyris reticu/ata, CYr/ospirijer sp. Ten/ieaspirijer cf. gOr/ani (SKP011 • SKP008)Shale and thin limestone with Schucher/el/a sp., Cyr/ospirijer sp., (SKPOO7)

light grey argillaceous limestone with Nayanne/la synplica/a, Cyr/ospirijer sp. (SKP006)

Shale bedded nodular limestone

Thin limestone

Yellow and green sandy shale

light grey sandy shale

Dark grey limestone

Shale and thin limestone

Dark grey thin limestone

Dark grey limestone and shale with sparse brachiopods (SK015)

4. Thin dark green nodular limestone with rare CYr/ospirijer sp. (SKP005)

3. Argillaceous limestone bedded nodular limestone

2. Dark grey limestone and argillaceous limestone with Productel/ana cf. linglingensis.Cyrtospirijer sp. (SKPOO4)

Calcareous argillites

Thin argillaceous limestone with sparse A/hyris reticula/a, Cyr/ospirijer sp. (SPK003)

Calcareous argillites with thin bedded limestone with sparse brachiopods (SKP002)

1. Dark grey limestone bedded shale with Schuchertel/a sp., Cyr/ospirijer sp.Bryozoan: AWc/%echus sp. (SKPOO1)

Shale with thin coal beds

roE

c:ro

~ - - 6.7.J:: f-.lL-rr-li---rr-1i..-j

~ t;i~~~~~~1--~357~.3~ \: 45.6(/)

5.6

5.0

13.0

32.8

fault

Figure 3 Generalized stratigraphic column for the Late Devonian sequences in Shashishan section (modified fromZhang et aI.1959). Horizons sampled by Zhang et al. are numbered 1 to 13. Numbers prefixed SKP refer toindividual collections of brachiopods made for this study.

5.

syllplicata, N. abrupta, Athyrisreticlllata, Tellticospirifer cf. gortalli(SKP017, SKP016)

361.6 m Yellow-brown shale and sandstone,dark grey limestone with abundantProdllctella slIbovata, Prodllctellalla cf.lillglingellsis, Avollia sp., Schllchertellasp., Ptychomaletoechia sp., Nayllmzellasljllplicata, N. abrupta, Athyrisreticlllata, Tellticospirifer cf. gortalli,

4. 5.5 m

3. 5.0m

2. 48.3 m

Cyrtospirifer sp., bryo2oanEridotrypella sp., cephalopods.(SKP015-SKP006)

dark green thin nodular limestonewith rare Cyrtospirifer sp. (SKP005)argillaceous limestone beddednodular limestonedark grey limestone, argillaceouslimestone, yellow-green calcareousmudstone with Prodllctellalla cf.

40

linglingensis, Cyrtospirifer sp.(SKPOO4002)

1. 120.0 m Dark grey limestone bedded shalewith Schuchertella sp., Athyrisreticulata, Cyrtospirifer sp.; bryozoanAtoctotoechus sp. (SKPOOl)

[Fault]Jurassic

COMPARISON WITH OTHER LOCALBRACHIOPOD OCCURRENCES

When compared with the log of the sectionconsidered herein, the Shashishan Formation isdifferent in the southeast of Yorgongbulak nearShashishan, where Late Devonian deposits of about1600 m in thickness are composed of grey, greyyellow thin limestone, calcareous tuffaceoussiltstone, intercalated argillaceous and calcareoussiltstone and sandy limestone. These have yielded abrachiopod fauna including: Productella subaculeatus,Yunnanella quadriplicata, Y. triplicata, Y. uniplicata,Nayunnella synplicata, N. supersynplicata, N.multiplicata, Camarotoechia subextensis, Atrypa sp. andTenticospirifer tenticulum as well as the coralsTabulophyllum longiseptum and T. trigomme(Compiling group of RSCX 1981: 293). Although thedeposits are considerably thicker than those of theShashishan Formation, they show some similarityin lithology and fauna. Based on the Atrypa andabundant Yll1lnanella in the fauna, the deposits inYorgongbulak appear to be Frasnian to EarlyFamennian in age. It is therefore possible that lowerhorizons in the Shashishan Formation may beequivalent to the upper part of the Yorgongbulakhorizons.

In Hejing County, the sediments of Late Devonian(Hazirbulak Formation, about 1614 m in thickness)are mainly composed of dark grey thick-beddedlimestone, bioclastic limestone, yieldingbrachiopods: Tenticospirifer, Productella,Camarotoechia, Yunnanella, Schellwienella (Compilinggroup of RSCX 1981). The Late Devonian sedimentsin Hejing County are similar to those of theShashishan Formation described herein, but to dateno elements of the Nayunnella fauna have beenreported. It could be that the beds bearing theNayunnella fauna of the Shashishan Formation arehigher than the Hazirbulak Formation, because thebeds containing the Naylmnella fauna are a littleolder than the beds bearing the Yll1lnanella fauna.

In Artungex, the deposits of early Late Devonian(Tangaitar Formation, 700-900 m in thickness)consist principally of limestone, intercalatedsandstone and sericite chlorite schist with abundantbrachiopods such as Atrypa, Hypothyridina,Schizophoria, Gypidula and corals such asPhillipsastrea, Iowaphyllum, and Megaphyllum. Thedeposits of Middle Devonian age (Tuogemaiti

Xiu-Qin Chen, Han-Kui Xu

Formation, 750-900 m in thickness) are mainlycomposed of limestone intercalated sericite schist,quartzose sandstone, argillaceous schist withabundant brachiopods including Emanllella,Undispirifer, Eoreticularia, Stringocephallls,Bornhardtina, Indospirifer and corals such asTenmophyllllm, and Alveolites. Similar deposits andfaunas of the Middle and Late Devonian mentionedabove are also found in Wushi (Compiling group ofRSCX 1981). In Arpishmebulak, Early Devoniandeposits (Arpishmebulak Formation, more than 300m in thickness) are mainly composed of dark greylimestone, grey-green calcareous shale, yieldingcorals, ostracodes, conodonts, brachiopods (Zhouand Chen 1990, 1992).

In summary, the deposits of Early Devonian toearly and middle Late Devonian in SouthTianshan are mainly composed of limestone,argillaceous limestone, mudstone and sandstonewith abundant brachiopods, corals, ostracodesand conodonts in many beds. These lithologicaland faunas characters suggest that EarlyDevonian to middle Late Devonian horizons inSouth Tianshan were deposited continuously inmarine conditions. No strong volcanicmovements and volcanic deposits occurredduring this time, especially from the Givetian intothe middle Famennian. We conclude, therefore,that the Pochengzi Formation which containsthick volcanics probably overlies the ShashishanFormation. Owing to the wide distribution ofvolcanics during the Late Devonian in SouthTianshan, many horizons contain rather sparsefaunas, thus there still exist problems in precisedating of many horizons requiring furtherinvestigations to be undertaken.

FAUNAL ASSMBLAGES AND AGE

The fauna of the Shashishan Formation iscomposed principally of 10 brachiopod genera inwhich rhynchonellids are dominant. Theseinclude Nayunnella synplicata and N. abrupta (201specimens), and Ptychomaletoechia sp. (16specimens). The only representative of theathyrids, Athyris reticlllata, is the second mostdominant group in the fauna (81 specimens). Thenext dominant group is the spiriferidsrepresented by Tenticospirifer cf. gortani andCyrtospirzJer sp. (50 specimens). Productids andstrophomenids are uncommon. The fauna of theShashishan Formation is divided into three: thelower part characterized by a few Cyrtospirifer;the middle part with many specimens ofNayunnella, Ptychomaletoechia, Athyris,Tenticospirifer, Prodllctellana and Avonia; and inthe upper part only a few Cyrtospirifer, and Athyrisoccur. As the lower and upper parts are mainlycomposed of dark grey limestone in contrast to

Famennian brachiopod fauna from South Tianshan, China

the middle part that consists of yellow and greencalcareous mudstone, the difference between thefaunas of the three parts may be the result ofenvironmental differences.

Although South Tianshan is far from Hunan, LateDevonian sequences of the two areas are similar toeach other both faunistically andsedimentologically. The fauna from XikuangshanFormation in Hunan can be divided into threeassemblages:• the lower fauna: YllIlIlallella IWllbllrtji-Cyrtiopsis

davidsolli assemblage;

• the middle fauna: Nayllllllella gralldisTellticospirifer gortalli assemblage;

• the upper fauna: Nayllllllella sllpersYllplicataTellticospirifer triplisilloslls assemblage (Yu et al.1990).

Although YllIlIlallella can be found from theLate Frasnian to Late Famennian, Nayllllllellaoccurs only from Middle Famennian to LateFamennian in Kazakhstan. According to Yu et al.(1990), Yllllllallella is commonly limited in EarlyFamennian and NaYllllllella is commonly found inthe Middle Famennian in South China. NayllllllellasYllplicata (Grabau) and N. abrupta, found in thelower part of the Shashishan Formation, arecommon elements in the N. gralldis-Tellticospirifergortalli assemblage in Xikuangshan Formation.Tellticospinfer cf. gortalli in the ShashishanFormation is similar to Tellticospirifer gortalli ofthe second assemblage in XikuangshanFormation. Both Nayllllllella and Tellticospirifercomprise 88°/<) of the total fauna of the ShashishanFormation. The part of the XikuangshanFormation yielding the second brachiopodassemblage, according to Yu et al. (1990), can bedated as middle Famennian (Palmatolepisrhomboidea and P. margillifera zones). It followsthat the age of the Shashishan Formationcontaining the NaYllllllella fauna must thereforebe of similar age. The close similarity of thesedimentary environment, preservation and sizeof the individuals, and the communitycomposition of the NaYllllllella fauna in theShashishan Formation and the brachiopods of thesecond assemblage in the XikuangshanFormation, indicate that both probably occupiedBenthic Assemblage 2-3 position (Boucot 1975).As the South Tianshan is situated on the marginof the continent platform, accumulation ofsediments would be far greater than in Hunanthus explaining the differences in thickness of thetwo.

SYSTEMATIC PALAEONTOLOGY

Specimens illustrated are housed in the NanjingInstitute of Geology and Palaeontology, ChineseAcademy of Sciences, Nanjing collections,

41

catalogued with the prefix NIGP. All are from theLate Devonian Shashishan Formation, collectedalong the Shashishan Section near Kruktag, SouthTianshan (Figure 2).

Order Strophomenida Opik, 1934

Superfamily Productoidea Gray, 1840

Family Productellidae Schuchert and levene, 1929

Genus Productella Hall, 1867

Type speciesProdllctlls sllbacllleatlls Murchison, 1840

Productella subovata sp. novoFigures 10.10-15, 18

Material5 conjoined valves.

Dimensions14-22 mm in length; 18-28.7 mm in width

DiagnosisA species of Prodllctella, suboval in shape and

with closely packed stout spines.

DescriptionShell small to medium sized, suboval in

outline with the length shorter than the widthand hingeline shorter than maximum width.Ventral valve convex, with greatest convexityin the posterior part of the valve; ventral beaksmall, slightly incurved; cardinal extremitiesusually subquadrate of slightly ear-shapedwith the basal part of the cardinal extremitiesbeing grooved. Ornament consisting ofnumerous irregular spines on the ventral valveand with the dorsal valve having more spineson larger indi vid uals and less spines onsmaller ones.

RemarksProdllctella slIbouata sp. novo may be compared

with P. slIbacllleata (Murchison) from Late Devonianin southern Xinjiang and is differentiated from thelatter by the ratio of width to length being largerthan that of the latter. The hinge line is short andincurved, no concentric rugae are present, and thespines stout and closer in the new species.

Genus Productellana Stainbrook, 1950

Type speciesProdllctellalla bijilria Stainbrook, 1950

42

Productellana cf. linglingensis Wang 1955Figures 10.1-3

Material1 conjoined valve.

DescriptionShell medium sized, subquadrate in outline with

hingeline straight, shorter than maximum width;cardinal extremities obtuse and rounded. Ventralvalve convex with slightly incurved beak, apexnarrow, slightly concave anteriorly. Dorsal valveconcave, little more flat near cardinal extremities.Surface marked by crowded concentric rugae, stoutand large spines, rare and scattered on ventralvalve; spines small and crowded arrangement ondorsal valve.

RemarksThe specimen has some similar characters of

Productellana linglingensis described by Wang fromthe Late Devonian, Lingling, Hunan Province (Yangand Wang 1955), especially regarding the in outlineand the arrangement of spines. P. linglingensis issubrounded in outline, with shell width about equalto length, concave near extremities, with more welldeveloped spines and rugae. The width is morethan the length for the specimens described hereand the interarea is less well developed. Insufficientmaterial precludes a positive identification of P.linglingensis Wang.

Genus Spinulicosta Zhang, 1983

Type speciesProductella spinulicosta Hall, 1857

?Spinulicosta xinjiangensis Zhang, 1983Figures 10.16, 17

Material1 ventral valve.

DescriptionShell medium-sized, elongately oval in outline

with hingeline forming the widest part; beak strongincurved, apex folded, ears developed. A fewirregular spines and costae on valve.

RemarksThe specimen is similar to Spinulicosta

xinjiangensis described by Zhang from LateDevonian in Kuoketiekehe, Bayinbuluk, Xinjiang(Zhang et al. 1983), especially regarding the outline,and the development of costae. Because there isonly one ventral valve in the collection, theassignment to S. xinjiangensis Zhang is queried.

Xiu-Qin Chen, Han-Kui Xu

Superfamily Avoniidae Sarytcheva, 1960

Genus Avonia Thomas, 1914

Type speciesProductus yOllngianlls Davidson, 1860

Avonia sp.Figures 10.4, 5

Material1 ventral valve.

DimensionsLength 12 mm; width 9.5 mm.

DescriptionShell small, elongately oval in outline with

hingeline straight, slightly shorter than maximumwidth. Strong convexity in the centre of ventralvalve; ears steep, small and flat with a troughformed between ears and rest of the valve. Sulcusnot well developed.

RemarksThe only one specimens illustrated herein is

similar to that of Avonia in outline, size andornament. Insufficient material precludesidentification to species level.

Suborder Strophomenidina Opik, 1934

Superfamily Davidsonoidea King, 1850

Family Schuchertellidae Williams, 1953

Subfamily Schuchertellinae Williams, 1953

Genus Schuchertella Girty, 1904

Type speciesStreptorhynchus lens White, 1862

Schuchertella sp.Figure 4; Figures 10.27-29

Material2 incomplete, conjoined valves.

DescriptionShell medium sized, transversely oval in outline

with hingeline shorter than maximum width.Ventral interarea 2.3 mm high, 3.0 mm wide with aconvex pseudodeltidium; ventral valve gentlyconvex near the beak, flat and concave near themiddle and anterior parts of valves. Dorsal valvegently convex, with greatest convexity at the middleof valve; interarea undeveloped. Surface marked by


0..., .....~ ....Jl'Omm1.21.0

~O. 7

1.4 2. 0 2.2

Figure 4 Transverse serial sections of Schllcherlella sp.

fine and closed costellate, 2-3 finer, secondarycostellae between two primary costellae; one finercostellae between primary costellae near lateralsides. Nine costellae in 5 mm at anterior margin.Interspaces wider than width of the costellae.Dental plates short, diverging from each otheranteriorly; internal structure of dorsal valve unclear(Figure 4).

beak pointed, slightly incurved with large foramen;sulcus shallow, widening and deepening anteriorly.Fold starting from the beak, becoming moreobvious anteriorly. Surface marked by simplecostae, interspaces shallow and with 5 costae on theventral sulcus and 6 costae on the dorsal fold.Dental plates thin and short; septalium small,supported by a median septum.

RemarksSchllchertella sp. illustrated herein is similar to

Schuchertella radialis (Phillips) from the EarlyCarboniferous in Meilukahe, Jinghe County,Xinjiang (Zhang et a!. 1983), especially regarding theoutline and size. Schllchertella sp. differs from thelatter in having 2-3 finer costellae between primarycostellae, and one finer costellae between two firstcostellae near lateral sides. S. radialis has 4-6 finercostellate between the two first costellate and hasalmost equal sized interspaces.

RemarksThe specimens illustrated herein are similar to P.

hllnanensis (Tien) from Xikuangshan Formation(Late Devonian) in Xinhua, Hunan Province but thelatter is larger and less convex and the interspacesof costae, some of which are bifurcate, widen morerapidlyanteriorly.

Family Yunnanelidae Rzhonsniskaya, 1959

Genus Nayunnella Sartenaer, 1961 (= YunnanellaGrabau, 1931)

Order Rhynchonellida Kuhn, 1949

Superfamily Rhynchonelloidea Gray, 1848

Type speciesYlInnanella synplicata Grabau, 1931

Family Trigonirhynchiidae Sartenaer, 1961

Genus Ptychomaletoechia Sartenaer, 1961

Type speciesRllljlJchonella ornalillsi Cosselet, 1877

Ptychomaletoecllia sp.Figures 12.5-8

Material16 conjoined valves.

DimensionsWithin the range of 8-10.3 mm in length, 9.9-11

mm in width, and 5.3-6.7 mm in thickness.

DescriptionShell small, subtriangular, sub-biconvex. Ventral

RemarksGrabau (1923) mentioned both YlInnanella

synplicata Grabau and Y. hanbllryi (Davidson) in hisarticle on Stratigraphy of China. He did not assign atype species to the genus YZlIJnanella nor did heformally describe the species at that time. Schuchertand Levene (1929: 130) assigned YlImzanella hanbllryi(Davidson) as type species of the genus YlIImanellaGrabau, 1923. However, Grabau (1931) erected anew genus YZl/1nanella and subgenus YZlIJlJalJellinawith type species YZlIJlJanella synplicata Crabau andY1IIlI1anella hanbllryi (Davidson). As this did notconcur with the international zoologicalnomenclature procedures, Sartenaer (1961) erectedthe genus, NayzlIlnella with type species YZlIJnanellasynplicata Grabau, 1931. Although YlIllIumella andYZlIlnanellina are recognised as junior synonyms ofNayunnella by most brachiopods workers (e.g.McLaren in Moore 1956), others, for example,


Ivanova (1961) and Ma (1995), believe that they canbe distinguished on features such as the differencesin the striae on the shell surface.

Figure 12.1-4) is 8.1 mm long, 8.2 mm wide and 3.2mm thick.

Nayunnella synplicata (Grabau, 1931)Figure 5; Figures 11.1-34; Figures 12.1-4, 9-14, 23-34

Material780 conjoined valves, 11 incomplete valves.

DimensionsGenerally within the range 10-16 mm in length,

12-20 mm in width, and 5-12 mm in thickness. Thelargest specimen is 23 mm long, 22 mm wide and15 mm thick while the smallest specimen (eg.,

DescriptionShell small to medium sized, subpentagonal in

outline, width commonly greater than length;juvenile specimens deeper than adult specimens.Hingeline short, cardinal extremities rounded withmaximum width close to midlength. Anterolateralcommissures low, indented by the costae andplications, as is the frontal commissure. Anteriorcommissure uniplicate. Ventral valve generallyslightly convex in the umbonal regional with flat toslightly concave anterolateral areas. Sulcusmoderately deep, starting imperceptibly betweenabout 30-50% the length of the shell forward of the

1. 150.90.8o. 6

1.2

o. 4

o 2 4mmL.'__...' __..I'

1.7 2.0 2.2

2. 5 2.8 3.2

Figure 5 Transverse serial sections of Nayunnella synplicata (Grabau)


beak, about between 30 -50'X, its maximum at thefront; the floor of the sulcus generally flat; hightrapezoidal tongue with sharp borders. Ventralbeak small and pointed with small circular foramen.Dorsal valve more convex than ventral valve, wellmarked fold starting some distance froward of thebeak, usually rapidly arched at the front; flanks offold steep.

Ornament consisting of costae originating somedistance forward of the beak increasing in numberanteriorly by bifurcation or, exceptionally, byintercalation. Costae combining into plicationanteriorly. In general 2 plications on sulcus, 3plications on fold; a few specimens with 1 or 3plications in sulcus, 2-5 plications on fold; 1-2costae between 2 plications. Dental platesdeveloped in the ventral valve; stout and shortseptum supporting a short, deep and uncoveredamphora-shaped septalium (Figure 5).

DimensionsWithin the range 9.8 11.6 mm in length, 16.4-31

mm in width, and 4.7-11 mm in thickness.

DescriptionShell medium sized, subtriangular in outline,

strongly dorsibiconvex with greatest width close tomidlength. Ventral valve gently convex, flanks andanterolateral sides flat; sulcus narrow, starting from1/3 the length of the shell forward of the beak,forming a prominent tongue. Fold starting from thecorresponding position of the sulcus, flanks steep.In general, 2 stout plications in sulcus and 3plications on fold, starting from the midlength andenlarged by a costae or combined by 2 costae; 3-5plications on each side, costae often evidentbetween 2 plications. Thin, short dental plates inthe ventral valve; septalium V-shaped (Figure 6).

RemarksIn the Shashishan Formation, Nayunnella

synplicata (Grabau) is the most abundant componentof the Nayunnella fauna. Specimens from the samehorizon in the section have from one to threeplications in the sulcus. In the past, the number ofplications in the sulcus was often the basis for theerection of a new species. However, numeroustransverse serial sections of internal structures haveproved that specimens from the same horizon withvarying numbers of plications in the sulcus areidentical in other respects. The number of plicationsin the sulcus should therefore be considered asintraspecific variation within in the species.

Nayunnella abrupta (Grabau, 1931)Figure 6; Figures 12.15-22

MaterialTen complete conjoined valves.

RemarksGrabau (1931) assigned Nayunnella abrupta a

subspecies of Nayzmnella synplicata on the basis ofboth forms having 2 plications in sulcus, and 3plications on fold. However, Y. abrupta differs fromY. synplicata in being more inflated, in having anarrow, prominent tongue, and simple plicationsenlarged by costae. After Tien (1938) studied thebrachiopods of Late Devonian from Xinhua,Ningxiang and Xiangxiang in Hunan, he designatedY. abrupta as a species, and erected 5 subspecies ofY. abrupta. The authors of this study re-examinedthe 5 subspecies collected from the same localityand found that the number of plications in thesulcus varied from 2 to 5, with some plicationsenlarged by costae and some combined by 2 costae.Although it can not be proved if Tien's 5 subspecieswere collected from the same horizon, it does notappear that the 5 subspecies of Y. abrupta are validbased on the present collection of specimens(SKP007-SKPOLO) collected from the same locality

2. 01.8\.61.41.2

ffi@88888O. 25 O. 7 O. 8 O. 85 O. 9 I. 0 I. OS

o 2I !

Figure 6 Transverse serial sections of Nayul1l1clla abrllpta(Grabau)


and same bed and having same internal structures.The variation of the number of plications in sulcusare best seen as intraspecific variation in Y. abrupta.

Superfamily Athyroidea M'Coy, 1844

Family Athyridae M'Coy, 1844

Genus Athyris M'Coy, 1844

Type speciesTerebratula concentrica von Buch, 1834

Athyris reticulata sp. novoFigure 7; Figures 10.6-9, 19-26; Figures 13.28-31

Material76 conjoined valves, 4 ventral valves, 1 dorsal

valve.

DimensionsWithin the range of 12-22 mm in length, 10-21

mm wide, and 8-16 mm in thickness.

Ventral beak incurved with a large foramen at theapex of the valve; a slightly narrow but prominentsulcus commencing from the beak, anteriorlybecoming a very strong tongue, making thecommissure strongly uniplicate; dorsal foldoriginating from the umbo with anterior andmiddle part prominent and the flanks of the folddepressed. The ornament consists of closedconcentric lamellae, crossed by numerous radialcostellae forming cancellate structure, with 7-8lamellae in a space of 2 mm near the anteriormargin of the shell. Hinge teeth stout, dental platesshort and thin. The hinge plates jointed anteriorlyforming perforate cardinal plate. Spiralia directedlaterally (Figure 7).

RemarksAthyris reticulata sp. novo is characterized by

possessing concentric lamellae crossed by finecostellae, forming cancellate structure. A. sulciferaNalivkin described from the HonggulelengFormation of North Xinjiang by Zhang et al. (1983)can be distinguished from A. reticulata by its smallershell, wider and deeper sulcus, and having onlyconcentric ornament.

DiagnosisA species of Athyris with concentric lamellae

crossed by fine costellae, forming cancellateornament.

DescriptionShells small to medium sized, subpentagonal in

outline, unequally biconvex with dorsal valve beingslightly more convex; hingeline approximatelythreequarters of the shell width, the maximumwidth at midlength; cardinal extremities rounded.

Order Spiriferida Allan, 1940

Superfamily Spiriferoidea Waagen, 1883

Family Cyrtospiriferidae H. and G. Termier, 1949

Genus Cyrtospirifer Nalivkin, 1918

Type speciesSpinfer verneuili Murchison, 1840

4. 5 5. 75. 14.9

rTn~~'·"V U, \' V'./ V

4.3

Figure 7 Transverse serial sections of Athyris retictl/ata sp. novo


OlD (fjj) CIJJ)O. ] 0.5

1. 0

IOmm'--_~__-J'

2. 0 3. 2

4. 5

6.8

Figure 8 Transverse serial sections of Cyrtospirifer sp.

Cyrtospirifer sp.Figure 8; Figures 13.1-10, 15, 16

7.0,.. 8

cardinal extremities, and a narrow and low sulcusand fold.


valves.

DimensionsThe collections include some small individuals

less than 6 mm long and 8.7 mm wide, and somelarge individuals up to 15 mm long and 20 mmwide.

DescriptionShell small to medium sized, semicircular in

outline, hingeline straight, shorter than maximumwidth; biconvex or slightly dorsibiconvex.Delthyrium large, partly covered by deltidial plates.Ventral sulcus and dorsal fold originating at beak;costae not clear in sulcus and on fold, butapproximately 20 costae on each flank. Dentalplates developed; cardinal process striate; cruralplates very short (Figure 8).

RemarksThe specimens are similar to Cyrtospirifer

Izeterosilllls (Crabau) from Xikuangshan Fom1ation(Late Devonian), Hunan, in outline, size anddevelopment of the ventral interarea but differ fromthem in having subquadrate cardinal extremities,and a more developed sulcus and fold. Thespecimens from the Shashishan section has acute

Genus Tenticospirifer Tien, 1938

Type speciesSpirifer telllueu/um de Vemeuil, 1845

Tenticospirifer cf. gortani (Pellizzari, 1913)Figure 9; Figures 13.11-14,17-27


valves.

DimensionsWithin the range 14.8-18 mm in length, 13.4-28

mm wide, and 10.3-14 mm in thickness.

DescriptionShells medium to large, subpentagonal in outline

with cardinal extremities blunt or alate, hingelineequal to maximum width. Ventral beak blunt,interarea 5-7 mm high, delthyrium narrow andhigh, delthyrium partly covered by delthyrial plate.The convexity of dorsal valve less than that ofventral valve; beaks slightly incurved, interareaorthocline. Ventral sulcus and dorsal folddeveloped, the width of sulcus occupying one-fifthof the width at the anterior commissure, apex offold flat, well-defined. Arrangement of costae


4320,-,__...:.i?__...::.l,OmlJt

5

Figure 9 Transverse serial sections of Tenticospirifer cf. gortani.

unclear on the ventral sulcus and on the dorsal fold;15-20 costae on each flank. Dental plates thin andlong; cardinal process striate, crural plates veryshort (Figure 9).

RemarksThe specimens illustrated herein are very similar

to Tenticospirifer gortani (Pellizzari) from Hanchangin Shensi (Grabau 1931) in outline, size, thedevelopment of cardinal extremities and interarea.As the arrangement of costae on the sulcus and foldis not clear, the specimens cannot be assigned to T.gortani with certainty.

ACKNOWLEDGEMENTS

This paper is an outcome of projects (4890012 and49972005) supported by the National NaturalScience Foundation. The authors are extremelygrateful to Professors John A. Talent and RuthMawson for editing the text, and to Prof. Yu ChangMin for providing excellent specimens for study.We thank Song Zhi-Yao for his photographic skillsand Ren Yu-Gao and Dean Oliver for skillfullydrafting the figures. This is a contribution toIGCP421 North Gondwana mid-Palaeozoic bioevent/biogeography patterns in relation to crustal dynamics.

REFERENCES

Boucot, A.J. (1975). Evolution and Extinction RateControls: 1-427, Elsevier, Amsterdam, Oxford, andNew York.

Compiling Group of the regional stratigraphic chart ofXinjiang Uygur Autonomous Region (RSCX) (1981).Regional stratigraphic chart of Northwest China, Xinjiang

Uygur Autonomous Region Volume: 1-49, GeologicalPublishing House, Beijing. (in Chinese)

Grabau, AW. (1923-1924). Stratigraphy of China, Part I,Palaeozoic and older: 1-200 (1923), 201-end (1924),Geological Survey of China, Beijing.

Grabau, AW. (1931-1933). Devonian Brachiopoda ofChina, Part I. Devonian Brachiopoda from Yunnanand other Districts in South China. PalaeontologicaSinica, Series B 3 (3): 1-454 (1931), 54 plates (1933).

Ivanova, E.A (1961). Yunnanella illi Nayunnella Sartenaer,1961. Paleontologicheskiy Zhurnal 1961 (4): 151-152.

Ma Xue-Ping (1995). The type species of the brachiopodYunnanelIina from the Devonian of South China.Palaeontology 38 (2): 385-405.

Moore, R.e. (ed.) (1965). Treatise on InvertebratePaleontology. Part H. Brachiopoda: 1-927, GeologicalSociety of America and University of Kansas Press,Boulder, Colorado and Lawrence, Kansas.

Pellizzari, e. (1913). Fossili Paleozoici Antichi delloScensi (Cina). Rivista ItaIiana di Paleontologia (Pavia) 19(2): 33-48.

Sartenaer, P. (1961). Note nomenclatoriale: YunnanellaGrabau, YunnaneIlina Grabau, NayunneIla nom.nov.(Rhynchonelles). Institut royal des Sciencesnaturelles de Belgique, Bulletin 37 (2): 1-3.

Schuchert, e. and Levene, e.M. (1929). Brachiopoda(Generum et Geontyporum index et bibiographia):Fossilium Catalogus, I, Animalia, part. 42: 1-140,Junk, Berlin.

Tien, e.e. (1938). Devonian brachiopods of Hunan.Palaeontologica Sinica, new Series B 4 (113): 1-192, 22pis.

Xu Han-Kui and Chen Xiu-Qin (1999). New Knowledgeof the Middle Famennian Shashishan Formation inKruktag, Xinjiang. Journal of Stratigraphy 23 (1): 31-37.(in Chinese with English abstract)

Yang Jingzhi and Wang Yu (1955). The Index Fossils ofChina (Invertebrates), Book II (Phylum Brachiopoda):

Famennian brachiopod fauna from South Tianshan, China

109-170, Geological Publishing House, Beijing. (InChinese)

Yu Chang-Min, Xu Han-Kui, Peng Ji, Xiao Song-Tao andLiu Zu-Han (1990). Devonian stratigraphy,palaeogeography and mIneral resources in Iiunan.Palaeontologia Cathayana 5: 85-138.

Zeng Ya-Shen and Xiao Shi-Lu (1979). Devonian ofXinjiang. Stratigraplllc specials of XlI1jiang RegionalGeological Survey 2: 1-162. (in Chinese)

Zhang Ri-Dong, Yu Changmin, Lu Lin-Huang andZhang Lin-Xin (1959). Paleozoic stratigraphy ofSouthern Part, Tianshan, XinJiang. Memolr of theInstitute of Palaeontology, Academia SlIlIca 2: 1--43 (inChinese with Russian abstract)

Zhang Chuan, Zhang Feng-Ming, Zhang Zi-Xin and

49

Wang Zhl (1983). Phylum Brachiopoda. In GeologicalPublishing House (eds), Palaeontological Atlas Off')SS!!.sor Northwest I\cgion (X1Il11ll1lg) Part II (Latc Palaco:olc)262-386, pis 86--145, Beiling (in Chinese)

Zhou Zhi-Yi and Chen Pei-Ji (eds) (1992) Biostratigraphyand geological evolution of Tarim: 1-316, SCiencePress. Beijing. (in Chinese; a corresponding Englishversion published in 1992)

Zhao Zhi-Xin and Wang Cheng-Yuan (1990). The age ofthe Hongguleleng Formation, Junggar Basin,Xinjiang. Journal of Stratigraphy 14(2): 145-146. (inChinese)

Manuscript received March 1999; accepted October 1999.


654321

78 9 10 11

12 1314 15

1617 19 20 21

18 22 23 24 25

28


.... Figure 10 1-3, Prodllctellalla cf. IUlglillgcll~i~ Wang. Ventral, lateral and dorsal views respectively of cOl1j()JI1ed valves ofNIGI' 128597, sample SKI'OlO, (x1.5). 4, 5, AUOIllIl sp. Lateral and ventral views \JIGI' 128598,sample SKI' 015, (x2) 6-9, 19-26 rcliclI/ala sp novo 6-9, anterior, ventral, lateral dorsal vIew:respectively of conjoined valves of NIGP128599, sample SKI' 010, (x2), 19-22. lateral, ventral.dorsal and anterior vIews respectively of valves of paratype NIGI' SKP017,23-26, ventral, anterior, dorsal and lateral vIews respectively of conjOIned valves of of NIGP128601, sample SKI'011, (x2). 10-15, 18. Prodllclclla ~lIbouala sp. novo 10, 11, ventral and vIewsrespectively of conjoined valves of NIGP 128602, sample SKI'013, (xL5). 12, 13, ventral and dorsal VIewsrespectively of conjoined valves of NIC;P 128603, sample SKI'013, (xl.5). 14, 15, 18, ventral, dorsal andlateral views respectively of valves of NIGI' 128603-1. sample SKI'O 13. 16,17,xllliiall.l:CII.';i~ Zhang. Lateral and ventral views respectively of NIGP128604, sample SKP013, (xl 27-29,c:,d'I1(·'/'P,·/"llo sp. Dorsal, lateral and ventral views respectively of conjoined valves of NIGP 128605,SKP007, (x2).


1 2 3 4 56

78 9 10 11

12 13 14 15

17 19 21

18

16

2223 24 25

28


~ Figure 11 1-34, 1-4, ventral, lateral, dorsal and anterior views respectively of conjoinedvalves of NIGP 128606, sample SKP018, , (x2). 5-8, anterior, ventral, lateral and dorsal views ofconjoined valves of NIGP 128607, sample SKP010 , (x2). 9-12, dorsal, anterior, lateral, and ventral viewsrespectively of valves of NIGP 128608, sample SKP01l, (x2). 13-15, ventral, lateral and dorsalviews respectively of conjoined valves of NIGPI28608-1, sample SKP010, (x2). 16-19, anterior, lateral, ventraland dorsal views respectively of conjoined valves of NICl) 128609, sample SKPOl1, (x2). 20-22, ventral,lateral and dorsal views respectively of valves of NICP 128609-1, sample SKPOlO, (x2). 23-26,ventral, lateral, anterior and dorsal views respectively of conjoined valves of NIGP 128610, sample SKP010,(x2). 27-30, lateral, anterior, ventral and dorsal views respectively of conJoined valves of NICP 128611,sample SKP010, (x2). 31-34, anterior, lateral, ventral and dorsal views respectively of conjoined valves ofNICP 128612, sample SKP01O, (x2).


1 2 3 5 6 7

4

8

13

9

14

10

15

11

16

12

17

1819 20 23

2122 24

25 26

2728

29


~ Figure 12 1-4, 9-14, 23-34, (Crabau), 1-4, ventral, lateral, dorsal and anterior views respectivelyof conjoined valves of NICP 128613, SKPOlO, (x2), 9, 10, ventral and dorsal views respectively of cOl:1Jom(~Li

valves of NICP 128613-1, sample SKPOI4, (x2), 11-14, lateral, ventral, anterior and dorsal views respectivelyof conjoined valves of NICP 128614, sample SKPOlO, 23-26, anterior, ventral, lateral and dorsal viewsrespectively of conjoined valves of NICP 128615, sample SKP0l4, (x2), 27-30, lateral, anterior, ventral anddorsal views respectively of conjoined valves of NIGP 128616, sample SKPOIO, (x2), 31-34, Anterior, lateral,ventral and dorsal views respectively of conjoined valves of NIGP 128617, sample SKP013, (x2), 5-8,PIt/chomaletoechza sI'. Lateral, ventral, dorsal and anterior views respectively of conjoined valves, NIGP128618, sample SKP0l5, (x2,5). 15-22, NaylIllllella abrupta (Grabau). 15-18, lateral, ventral, dorsal and anteriorviews respectively of conjoined valves, NIGP 128619, sample SKPOlO, (x2). 19-22, ventral, anterior, dorsaland lateral views respectively of conjoined valves, NIGP 28620, sample SKP007, (x2.5).


17

9

10

5

16

8

4

7

15

2

6

12

1

3

11

23

19

22

18

21

14

20

13

24 25 26 27

-------------- -


..... Figure 13 sp. 1-4, ventral, dorsal, antenor and lateral views of valvesSKPOI4, 5-8, ventral, anterior, lateral and of

128622, SKP007, 9, 10, 15,16, anterior, and dorsaln>,n"di,\'"I" of valves, NICP 128623, sample SKP010, (x2). 11-14,17-27, cL

11-14, lateral, anterior, dorsal and ventral views respectively of conjoined valves ofNICP 128624, sample SKPOI3, (x2), 17-20, lateral, ventral, dorsal and anterior views respectively ofconjoined valves of NICP 128625, sample SKPOll, (x2). 21-24, anterior, ventral, dorsal and lateral viewsrespectively of conjoined valves, NICP 128626, sample SKP013, (x2.5). 25-27, dorsal, lateral and ventralviews respectively of conjoined valves of NIGP 128627, sample SKPOlO, (x2). 28-31, Athyris reticulata sp.novo Ventral, lateral, anterior and dorsal views respectively of conjoined valves of paratype, NIGP 128628,sample SKP013, (x2).

brachiopod fauna of the shashishan formation (mid ...museum.wa.gov.au/sites/default/files/3. chen,...

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