Triassic Brachiopods from Nepal

MILOS SIBLIK

Triassic Brachiopods from Nepal

MILANO Giugno 1975

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Riv. Ital. Paleont. : v. 81

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n. 2

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pp. 133-160

tav. 19-21

'1"'" M . 1Ol ano 1(' .' -)';)

TRIASSIC BRACHIOPODS FROM NEPAL

MILOS SIBLIK

Riassunto. Vengono descritte otto specie di Brachiopodi appartenenti ai Rhync}lonellida, Spirijerida e Terebratulida, provenierlti da rocce del rrriassico medio del Nepal. Tra di esse una nuova specie: .41lstriellula juchsi. In prevalenza si tratta di forme del-

l'Anisico,. confrontabili con le classiche faune di Spiti. Abstract. Eight species of Mid.dle Triassic Brachiopods from Nepal are described. They belong to Rhynchonellida, Spirijerida and Terebratulida, and include a nevv species: Austriellula juchsi. Most of them are of Anisian age and are correlatable with

the classical faunas from SpitL

This paper deals with Triassic Brachiopods coming from the Tibetan (Tethys) Zone of Dolpo, northwestern ~~epal-Himalayas. The collection was made in 1963 and 1973 by Dr. Gerhard Fuchs who was a member of Austrian Himalayan expeditions. I would lil~e to express my g'ratitude for the permission to study this valuable material to Dro Harald Lobitzer (Geologische Bundesanstalt Museum in Vienna, where the specimens are deposited), and to Dr. Gerhard Fuchs (Geologische Bundesanstalt, Vienna) who in addition kindly supplied me vvith necessary information about the localities. The Brachiopod fauna described here derives mostly from the Mukut Limestone (a formation of dark limestone, marls and shales) of Anisian Lower Carnian age, or from the underlying dark nodular limestone-shale horizon of the lowermost Anisian. The Brachiopod localities: 1. F 76 (expedition 1973) nodular lilnesto11e of lowermost Anisian (?), Pass 5310 m, 7,1 km NW of Phopa: Spirijerina cf. stracheyi (Salter).

Ammonites.

134

M. Siblik

2. F 77 (1963) Mukut Limestone, 4

l~m

E of Mukut: Spirijerina cf. stracheyi

( Salter). 3.F. 79 (1973) nodular limestone of lowermost Anisian, c. 200 m ENE of Phopa:Dielasn2a himaZayatltl1n Bittner, Spirijerina stracheyi (Salter), K oeves kalli1la lcoeves kal ye1'lsis spi tiensis (S toliczka), S1Jirigerellirla s toliczkai (Bittner). Amrrlonites. '1llle Brachiopod fauIla proves the Al1isian

age, horizon of Spirijerina stracheyi. 4. F 101 (1973) Mukut Limestone, E of Ghyallong Rauna Lekh (on sheet K 62 of 1" == 1 Mile Map of Nepal, 2 km SW of point 14570 and 15 1,8 km SE of point 16630, fossil locality 7,1 km SW of Phopa): ? Pe~Ti­ della aff. hllnica (Bittner),Austriellula juchsi sp. n . .t\mmonites, Dao-

nellids, Crinoids. Ladinian

(?) -

Carnian

(?)

5. F. 102 (1963) -higher Mukut Limestone, 1,2 km SW of Barbong' (Barbung Khola): ? Austriellula juchsi SPa n. Ammonites, Daonellids. Ladinian (?) -

Carnian

(?)

6. F. 126 (1973) lowest 2 m of Mukut Limestone, bridge over Panjang Khola, W of Yanjar Gompa: Koeveskallina koeveskalyensis spitiensis (Stoliczka), Spirigerellina stolicz7(ai (Bittner).A.nisian.

7. F. 142 (1973) doubtful because of structural complications, 900 m SW of Bijor: Dielasma (?) cf. julicum (Bittner), {( Spirijerina» aff. orophila

Diener. Bivalves. The Brachiopods suggest that is is probably young'er than Anisian. 8. F 166 ( 1963 ) M uku t Limes tone, Thinigaon (Kali Gandaki Valley):' « Rhynchonella}) cf. mutabilis Stoliczka.

It appears that there has not been any new stratigraphic evaluation, of the Triassic Himalayan Brachiopods since Bittner's and Diener's time, except for Westermann's (1962) correlation of the Spirijerina stracheyi horizon. According to Bittner (1899) ({ Spirijerina Stracheyi», « Spirigera Stoliczkai}) and « Terebratula (Dielasma) himalayana» are the most abundant Brachiopods occurring in the «Spirijerina stracheyi horizon». Westermann (1962) correlates the Himalayan Durgaites dieneri zone [== Sibirites prahlada zone] containing Spirijerina stracheyi with the Paraceratites binodos1~S zone of tIle Alpine succession (early late Anisian age). In the CaIladian Rocky Nlountains the Spirijerina stracheyi horizon represents (according to 1Nesterl11a11n) the base of the late Anisian « Beyrichites - Gymnotoceras - Parapopanoceras fauna».

TRIASSIC BRACHIOPODS FROM

135

NEPAL

The preservation of our material is not very good; most of the specimens are fragmentary or deformed by pressure. The scarcity of suitable material precluded tI1e sectioning' of more than 1 or 2 specimens and In some cases made the ellJcid"atio11 of the internal characters difficult or even impossible. The IJUrpOSe of the present paper will not be fully accomplis11ecl until it is followed by a paper 011 the detailed geology or biostratigrapllY of the area,. The prelin1inary report on tIle g'8olog'y of the region visited during the 1973 expedition w:.:tS published recently (Fuchs, 1975). The location of the localities of the 1963 expedition can be found in the paper by the same autl10r (1967, pI. 7).

descriptions

Palaeontological

Order Suborder

TEREBRATULIDA

Waagen, 1883

TEREBRATlJLIDINA

Waagen, 1883

Superfamily Die l a s m a t ace a Schuchert, 1913 Family Die l a s n2 a t i d e Schuchert, 1913

Genus Dielasma King, 1859 Dielasma himalayanum Bittner, 1898

PI. 19, figs. 1, 3; Text-figs. 1 a, 1 b, 2 1865 1898 1898 1899 1907 1920

Waldheimia Stoppanii - Stoliczka, p. 44. Terebratula (Dielasma) himalayana Bittner, p. 691. Terebratula tangutica Bittner, p. 691. Terebratula (Dielasma) HimaZayana - Bittner, p. 25, pl. 5, figs. 1-8, 10-11. Dielasma himalayanum - Diener, p. 5. Dielasma tanguticum - Diener, p. 92.

8 incomplete specime11s witll joined valves preserved as .partly deformed and fragmentary internal mould.s with shell remains . MATERIAL.

DIMENSIONS

(in mm): length of

length

brachial valve

widtll

thickness

c. 29,0

24,9

?.

13,0

sectio11ed specimen, Geol. Bundesanst. Wien (Muscu.nl), plaster copy no. 1975 03/01

c. 24,5

22,1

18,9

12,1

PI. 19, fig. ;3.

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15,6

9,7

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Fig. L,Jl -.~Jas1ruz himaZayanum Bittner;' 1898. ' Serial, ;tr'aDsrerse,' 'sections through the ' . 'posteriorpatt of the shen. 'Original lencPI o( speeim~ a.asp mm. ENEof . PhOP8~ l~c~ F. 79 (l973);, G13W (~)no. 18'75103/01~ '~. ~, .~~~ ~appro~. (~tinued). _.

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M. Siblik

138

Elongated and smooth biconvex shells with the :maxj.:mu:mwidth situated usually forward of mid-length. Pedicle valve :more convex than the brachial. An only slightly noticeable fold is to be seen near ;!fe anterior commissure in the brachial valve. Anterior commissure with low uniplication. Pedicle umbo rather prominent, erect to suberect, with oval foramen permesothyridid (?). in position. Sub rounded . beak· ridges present. Rare concentric ornament to be seen near the commissure, poorly developed radial capillae ascertained on the flanks of 1 specimen. Punctation mostly visible. DESCRIPTION.

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cimen. Original length of specimen about 20,0 mm. ENEof Phopa, loc. F 79 (1973); X 5 approx .

. No observations were made concerning muscle scars. In the pe·dicle valve ther~ are slender and relatively very short subparallel dental lamellae, limiting a subquadrate ' delthyrial cavity. The hinge - teeth are strong and inserted almost vertically into their sockets. They do not appear to be crenulated. The lateral denticula are well-developed. Pedicle collar not observed. The most obvious feature in the brachial valve is the presence of crural plates touching the' bottom of the valve without forming septaliu:m . . They are straight and much thinner than the outer hinge-plates and inner socket-ridges. But the laterally arched form of crural plates was also observed in connection with thin outer hinge-plates (Text-fig. 2). The crural bases are clearly distinguishable; given off ventrally. A low median ridge is present in the posterior third of ,the, brachial valve. Loop short, with short but high crural. proce'sses. The bad preservation of both specimens .s ectioned did not - allow ,me to observe the pedicle collar and . the anterior parts of loop · toget~er with the transverse band.

TRIASSIC BRACHIOPODS FROM

NEPAL

139

REMARKS. The characters observed agree well with those of specimens figured by Bittner (1899). It appears that the species has not been further studied in more detail since that time. The specific name of « tang'uticum » falls into synonymy as it was introduced by Bittner (1898) only to avoid the confusion with Permian «Terebratula himaZayensis» Davidson, 1862 [== Hemiptychina himalayensis (Davidson)]. However, both suffixes are different and therefore these two names can not be considered homonims • In any case. The generic identification may give rise to some doubts, because genus Dielasma is considered in recent literature an Upper Palaeozoic element only (Upper Mississippian - Permian,. after Stehli in Moore, 1965). But all the external and internal characters (recognized herein) of my specimens agree quite well with the characteristic features of Dielasma. Also according to Dagys the species under consideration reveals more affinities to Dielasma than to Adygella Dagys, 1959 (Dagys, 1963, p. 167) or to Fletcherina Stehli, 1961 (Dagys, 1965, p. 140) [== recte Fletcherithyris Campbell, 1965] although both the latter genera include some of the Triassic Dielasma-like forms. OCCURRENCE. Anisian. NW-Nepal (Dolpo): c. 200 m ENE of Phopa (loc. F 79-1973). Localities mentioned by Bittne·r (1899): Rimkin-Paiar, Lilang, Rajhoti Pass in Niti, Kali River valley; by Diener (1907): Kalapani, Kaga, NW of Po, Muth, Thanam valley, ridge between Dharma and Lissar valleys, and by Diener (1913): E of Guryul ravine. Dielasma (?) cf. julicum (Bittner, 1890)

MATERIAL. 1 incomplete, deformed specimen (internal mould with shell fragments) with dimensions of 14,0 x c. 13,0 x 7,7 mm (length x width x thickness). REMARKS. Biplicate shell reminiscent of the Carnian species Adygella julica (Bittner, 1890) [== Dielasma julicum, the generic affiliation to Adygella after Dagys, 1963, 1974J but due to bad preservation definitive determination is not possible. Dorsal septum and short dental plates visible on the mould. OCCURRENCE. Probably younger than Anisian. NW-Nepal (Dolpo): 900 m SW of Bijor (lac. F. 142-1973).

TRIASSIC BHACI1:IOPODS FHOM

Order Suborder

SPIRIFERIDA

141

NEPAL

Waagen, 1883

SPIRIFERINIDA

W"aagen, 1883

Superfam.ily S p i r i! e r i n ace a Davidson, 1884

Family S p i r i fer i n i d a e Davidson, 1884 Genus Spirijerina d'Orbigny, 1847 Spiriferina stracheyi (Salter, 1865) ')0 figs • PI fig'. 2' " • 19 " , PI ..;,..j,

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Spiri/er Stracheyi Salter in Salter & Blanford, p. 72 (tide Westerr[lann, 1962). Spirijer (Spiriferina) Stracheyi - Stoliczka, p. 38. Spiriferina Slrach,eyi - Bittner, p. 18, pI. 4, figs. 3··14. Spirijeri'na Stracheyi - Diener, p. 2, pI. 1, fig. 6. Spirijerina Stracheyi - Diener, pp. 97, 112, pI. 12, fig. 19; pI. 13, figs. 22-24. 1962 ({ Spirijerina» (Lepismatina?) stracheyi - Westermann, p. 600, 1)1. 1, figs. 1-10; pI. 2, figs. 1-12; P 1. 3, figs. 1-7.

1865 1865 1899 1907 1913

MATERIAL.

25 fragmentary specimens with both valves and 14 single

valves, more or less deformed and decorticated. DIMENSIONS

(in mm):

length

length of brachial valve

width

thickness

c. 19,0

14,4

c. 225 ,

13,5

PI. 20, fig. 3, slightly deformed.

c. 18,0

12,8

c. 23,0

11,5

PI. 20, fig. 2.

17,4

12,9

23 ,5

11,8

sectioned, Geol. Bundesanst. Wien (Museum), plaster copy, no. 197 5/ 0~3 / 11 .

14,4

11.6

c. 29,0

9,6

PI. 20} fig. 1.

The external characters are described in detail by Bittner (1899) and completed by Western1ann (1962, 1964). The description of Rocky Mountains specimens given by the latter author fits irl very well with that of our material, including the great range of variability. DESCRIPTION.

The dental lamellae are very short, diverging close to the umbo ventrally, and sl1arply bent inwards anteriorly (Fig. 3, section 3,0). Ventral septum extending to half the length of shell. The hinge-teeth strong, WIthout crenulation. Denticula may be present. Cardinal process bifid, welldeveloped (contrary to the observation by Westermann, 1962, p. 607). Dorsal septum very short, developed only close to the dorsal umbo ,or absent. Low median ridge present. The sockets broad but relatively shallow with well-defined inner socket-ridges. Spiralia not completely

M. Siblik

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M. Siblik

DESCRIPTION. Smooth biconvex shells of mostly subpentagonal outline" normally with length a little exceeding width, or length equal to width. In lateral profile, the brachial valve slightly more convex than the pedicle one. Uniplication strong, fold and sulcus very well defi11ed but not sharply delimited and noticeable only in the anterior half of shell. Cardinal margin somewhat curved. Pedicle umbo robust. A weak concentric ornament visible on the whole surface. Irregular, poorly developed radial ribbing visible in 1 specimen. The strong thickening of shell in the umbonal parts mentioned previously by Bittner (1899) is present in some of our specimens. Shell impunctate. Muscle scars not well enough preserved to enable one to discern between individual muscles. Ventral muscle area deep, pyriform in outline and about half of the length of the valve. Dorsal muscle area shallow, narrow and elongate with its anterior edge indefinite, reaching the midlength of the valve. Vascular and genital markings poorly impressed. Pedicle valve with strongly developed, long and subparallel dental lamellae and fairly broad lateral cavities. Posteriorly sub quadrate del thyrial cavity without myophragm. Lateral cavities partly filled with seC011dary calcite. Stout hinge-teeth are simple in shape, lacking in crenulation and inserted almost vertically. Low denticula present. In the brachial valve there is a very massive, undivided hinge-plate, without any posterior perforation. More or less well-defined crural process present. The sockets broad and deep, with smooth surface and strongly developed socket-ridges. Blunt and short denticula discernible. Secondary calcite infilling the coelomic cavity, dorsally of the hinge-plate. Short septoidal ridge visible posteriorly. The crural bases given off ventrolaterally from the hinge-plate. Slender crura diverge towards the pedicle valve. Spiralia consisting each of about 10 volutions orie'ntated towards posterolateral parts of shell. Saddle-shaped jugum projecting forward and giving a posterior rise to the jugal stem. The jugal stem bifurcating at its distal end into a pair of jugal arms, terminating laterally to the primary lamellae. REMARKS. The common attribution of the species under consideration. to the genus Athyris is conventional. i\ll external and many internal characters fit in with the genus mentioned but, the apical piercing of the cardinal plate that is characteristic for Athyris, is missing in « stoliczkai». On the other hand, the internal characters of « stoliczkai )} (including presence of apical perforation and the well-developed cardinal process) tog'ether with the external characters remind 011e of the genus

TRIASSIC BRACHIOPODS FROM

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Fig. 7 - Spirigerellina sioliczkai (Bittner, 1898). Two serial sections through another specimen. Original length of specimen about 19,0 mm. W of Yanjar Gompa, loc. F 126 (1973). x 5 approx.

Oxycolpella Dagys, 1962 that includes some of species previously included within Athyris. Dagys himself (1965, p. 133) mentioned the resemblance of his Norian Oxycolpella ochotica sp. n. to Spirijerina (Athyris) stoliczkai. Even if the material studied here is insufficient to make possible

a decisive solution of the problem, it seems to me quite reasonable to follow Dagys' attribution of « stoliczkai» to his new genus Spirigerellina (1974).

OCCURRENCE. Anisian. NW-Nepal (Dolpo): c. 200 m ENE of Phopa (loc. F 79-1973, 9 specimens); bridge over Panjang Khola, W of Yanjar Gompa (loc. F 126-1973, 4 specimens). Bittner (1899) mentioned the following localities: Rimkin Paiar, Spiti-Lilang, Dranghar, Kuling Khar, Rajhoti Pass in Niti, Diener (1907): Kalapani, Jolinka, Byans, Bambanag cliff, Kaga (Spiti), Muth, NNW of Po, and Parona (1928): Karacorum Pass and Ciagios-Gilgha. From Primorie is the species reported by Dagys (1974). Occurrence in Timor (Krumbeck, 1924) is problematic. Genus Pexidella Bittner, 1890 ?

Pexidella aff. hunica (Bittner, 1899) PI. 21, fig. 4

MATERIAL. 1 partially decorticated specimen with both valves but without the umbonal portion of the pedicle valve. Its dimensions are c. 14,0 x 13,4 x 7,8 mm. REMARKS. Our specimen shows a considerable resemblance to the Ladinian Spirigera hunica Bittner, 1899 especially as fig'ured by Diener

150

M. Siblik

(1908) in plate 2, fig~ 10. Bittner's species is, 11o'Never, c11aracterized by a much stronger development of the posterior IJart of the pedicle valve and by the relatively g'reater thickness of t118 :3hell. OCCUHRENCE.

N\t'\r~r~epal

(Dolpo):

E

or

Ghyallong Raurla Lelch (lac.

F 101-1973).

Order RHY]\ICHONELLIDA Kuhrl, 1949 SLlperfalnil:>l R h Y n c h 0 n e II ace a Gray, 1848 Fa,mily Dim. ere II i d a e Buckman, 1918 Subfarrlily Iv 0 r e II i n a eAger, 1959 Genus Austriellula Strand, 1928 Austriellula fuchsi sp. n. PI. 19, figs. 4, 6; Text-fig. 8

TYPE SPECIMEN. The holotype is figured on PI. 19, fig. 4 and deposited in the collections of the Geologische Bundesanstalt in Vienna (Museum) 'under register number 1975/03/13. STRATUM TYPICUl\I ET LOCUS TYPICUS.

Mul~ut

Limestone (Anisian-Car-

nian), E of Ghyallong Rauna Lekh (lac. F 101-1973). Sheet 62 __ r~. of 15 I" == 1 Mile Map of Nepal, 2 km SW of point 14 570 and 1,8 km SE of point 16 630, 7,1 km SW of Phopa. DERIVATIO NOMINIS. In honour of Dr. Gerhard Fuchs who has done so much for Himalayan geology. MATERIAL. 2 complete specimens preserved as internal moulds with shell fragments, and 1 qLlestionable strongly deformed pedicle valve. DIMENSIONS (in mm): length

width

thickness

12,7

12 ,7

7,9

holotype

11,1

120 ,

77 ,

PI. 19, fig. 6, slightly deformed., sectioned

DESCRIPTION. RathEr small unequally biconvex sn100th shells, subpentctgonal in outline and uniplicate. Maximum-length is about tIle same as width. Anterior margin straight in dorsal view. TIle rnaximum-width situated forward of the mid-length and the maximurrl-thiclcness near the anterior margin of shell. The brachial valve has strongly inclined

TRIASS I C BRACHIOPODS FRO M

NEPAL

151

flanks, about three times higher in lateral view than the poorly inflated pedicle valve. Moderately developed low fold and sulcus noticeable in the anterior halves of the valves. Anterior commissure with relatively high plication for ming subangular linguiform extension. Beak suberect with submesothyridid (?) foramen and well-developed beak-ridges. Apical angle 100-120". Muscle scars unknown.

Fig. 8 - Austriellula juchsi sp. n. Serial transverse sections through the posterior part of the shell. Original length of specimen 11,1 mm. E of Ghyallong Rauna Lekh, loco F 101 (19731. GBW (M) n o . 1975/ 03 / 14. x 8 approx .

The sub quadrate delthyrial cavity flanked by subparallel dental lamellae, which persist anteriorly until the teeth have been inserted completely in the sockets. The teeth stout, not crenulated. Denticula poorly marked. The muscle attachment areas well developed as deep depressions in the shell. There is a Well-developed median septum present in the brachial valve coming into contact with short septalial plates only at the posterior extremity. The inner socket-ridges better developed than the outer ones. The hinge-plates a lmost horizontal with crural bases distinguishable at

M. Siblik

152

their inner ends. The sockets large, becoming rather shallow in some sections. The crura posteriorly trigonal in cross-section, their distal termination not preserved. The partial recrystallisation of the specimen sectioned precluded getting more detailed information concerning internal characters.

REMARKS. The species described here is very closely allled to Bittner's {( Rhynchonella dilatata group» that comprised most of the smooth Rhynchonellids from Upper Triassic Hallstatt limestone. Considerable external resemblances could be found in some variants of Austriellula dilatata (Suess, 1855) itself, {( Rhynchonella » anguli/rons Bittner, 1890, {( Rhynchonella» annexa Bittner, 1890, {( Rhynchonella» generosa Bittner, 1890, {( Rhynchonella» subanguli/rons Krumbeck, 1924 and Austriellula go morensis (Balogh, 1940). The specific independence of our specimens is based on their subpentagonal outline (with its straight anterior part), their great difference in thickness of the dorsal and pedicle valves, their high uniplication and absence of any initial ribbing. Such ribbing is characteristic of {( Rhynchonella» anguli/rons Bittner (as mentioned by Diener (906) from Byans). (Austriellula /uchsi sp. n. has no affinity with the ribbed {( Rhynchonella Fuchsii» Bittner, 1903. That form was described from Bosnian Middle Triassic and it IS externally of Piarorhynchia-like character). OCCURRENCE. Ladinian (?) - Upper Triassic (?). NW-Nepal (Dolpo): E of Ghyallong Rauna Lekh (loc. F 101-1973, 2 specimens), 1 strongly deformed pedicle valve most probably of the species under consideration originates from SW of Barbong (loc. F 102-1963).

Family Rh Y n ch

0

n e II i cl a e Gray, 1848

Genus Rhynchonella Fischer, 1809 - sensu lato «

Rhynchonella» cf. mutabilis Stoliczka, 1865

MATElUAL. 1 incomplete laterally compressed and deformed pedicle valve about 18 mm long and 11 mm wide. REMARKS. Semicostate medium-sized shell without any parallel among the Himalayan fauna except for {( Rhynchonella» mutabilis Stoliczka, 1865. There are 7 moderately sharp ribs developed on the anterior half of the valve fragment; 4 of them seem to be confined to the shallow sulcus. Posterior part of the shell smooth.

lRIASSIC BRACHIOPODS FROM NEPAL

Age uncertain. Valley (loc. F 166-1963). OCCURRENCE.

NW-Nepal:

Thinigaon,

153

Kali

Gandaki

REFERENCES BALOGH K. (1940) - Daten zur geologischen Kenntnis der Umgebung von Pelsocard(). Abh. Miner.-Geol. Inst. st. Tisza-Univ. Debrecen, n. 19, pp. 149-181, 1 pI., Debrece:'l. BITTNER A. (1898) - Beitrage zur Palaeontulogie, insbesondere der triadischen Ablagerungen zentralasiatischer Hochgebirge. Jo. K. K. Geol. Reichsanst., v. 48, pp. 689-718, 2 pI., Wien. BITTNER A. (1899) - Trias Brachiopoda and Lamellibranchiata. Palaeont. Indica, s. 15, v. 3, n. 2, pp. 1-76, 12 pI., Calcutta. BITTNER A. (1903) - Brachiopoden und Lamellibranchiaten aus der Trias von Bnsnien, Dalmatien und Venetien. Jb. Geol. K. K. Reichsanst., v. 52, pp. 495-642, 10 pI., Wien. DAGYS A. S. (196:;) - Upper Triassic Brachiopods of the Southern DSSR tin Russian). Akad. Nauk, Sibir. otdel., pp. 1-238. :n pL, Moskva. DAGYS A. S. (1965) - Triassic Brachiopods of Siberia (in Russian). Akad. Nauk, Sibi;-. otdel., pp. 1-186, 26 pI., Moskva. DAGYS A. S. (1974) - Triassic Brachiopods (morphology, classification, phylogeny, stratigraphical significance and biogeography) (in Russian). Trans. Inst. Geo!. Geophys .. Acad. Sci. USSR, Siber. branch, n. 214, pp. 1-322, 49 pI., Novosibirsk. DIENER C. (1906) - The fauna of the Tropites-limestone of Byans. Palaeont. Indica, s. 15, v. 5, n. 1, pp. 1-201, 17 pI., Calcutta. DIENER C. (1907) - The fauna of the Himalayan Muschelkalk. Palaeont. Indica. s. 15, v. 5, n. 2, pp. 1-140, 17 pI., Calcutta. DIENER C. (1913) - Triassic faunae of Kashmir. Palaeont. Indica, n.s., v. 5, n. 1, pp. 1-133, 13 pI., Calcutta. DIENER C. (1920) - Brachiopoda triadica. Fossilium Catalogus. 1. Animalia, v. 10, pp. 1-108, Berlin. FUCHS G. (1967) - Zum Bau des Himalaya. Denkschr. osterr. Ak. Wiss. (Matem.-naturwiss. K/.), v. 113, pp. 1-211, 21 pI., Wien. FUCHS G. (1975) - On the geology of the Karnali and Dolpo regions, West Nepal. Clar· Festschr., Mitt. Geol. Ges .. v. 66-67, pp. 21-32, Wien. Hsu TE·YOU & CHEN K. (1943) . Revision of the Chingyen Triassic fauna from Kueichou. BUll. Geol. Soc. China, v. 23, pp. 129-138, Peking. KRUMBECK L. (1924) - Die Brachiopoden, Lamellibranchiaten und Gastropoden der Trias von Timor, n. Paldont. von Timor, n. 13, pp. 143-411, 20 pI., Stuttgart. LOGAN A. (1964) - An Indo-Pacific Spiriferinid from the Triassic of northeastern British Columbia. Bull. Canad. Petr. Geo!., v. 12, pp. 692-718, 2 pI., Calgary. LOGAN A. (1967) - Middle and Upper Triassic Spiriferinid Brachiopods from thf Canadian Arctic Archipelago. Geol. Surv. Canada Bull .. n. 155, pp. 1-37, 5 pI., Ottawa. MOORE R. C. (Edit.) (1965) . Treatise on Invertebrate Paleontology, Part H, Brachiopoda. Geol. Soc. Amer., Univ. Kansas Press, (2 v.), pp. 1-927, 746 text-fig., Lawrence, Kansas. PARONA C. F. (1928) . Faunette triassiche del Caracorum e degli altipiani tibetani. Spediz, ital. De Filippi. s. 2, v. 6, pp. 1-39, 2 pI., Bologna. PHILIPPI E. (1895) - Beitrag zur Kenntniss des Aufbaues und der Schichtenfolge im Gri· gnagebirge. Zeit Deutsch. Geol. Ges .. v. 47, pp. 665-734, 3 pI., Berlin. SALOMON W. (1895) Geologische unci palaeontologische Studien uber die Marmolata. Palaeontographica, v. 42, pp. 1-210, 8 pI., Stuttgart. SALTER J. W. & BLANFORD (1365) - Palaeontology of Niti in the Northern Himalayas. Cal· cutta (non vidil. SIBLIK M. (J970) Osservazioni nomenclaturali su {( Spiriferina lcoveskalliensis », Bra· chiopodo medio·triassico. Riv. Ital. Paleant. Strat., v. 76, pp. 347-349, Milano. STOLICZKA F. (1365) - Geological Sections across the Himalayan Mountains, from Wangtu· bridge on the river Sutlej to Sungdo on the Indus: with an account of the forma· tion in Spiti, accompanierl by a revision of all known fossils from that district. Mem. Geol. Surv. India, v. 5, n. 1, pp. 1-154, 10 pI., Calcutta.

154

M. Siblik

WESTERMANN G. E. G. (1962) The Mid- Triassic Brachiopod ({ Spiriterina» stracheyi (Salter) from the Canadian Rocky Mountains. Journ. Alberta Soc. Petr. Geo/., v. 10, pp. 593-609, 3 pI., Calgary. WESTEHMANN G. E. G. (964) - Possible mechanical function of shell plication in a Triassic brachiopod. Canad. Journ. Earth Sc .. v. 1, pp. 99-120, Ottawa. Geological Institute, Czechoslovak Academy oj Sciences, Prague.

Fig. 1 - Dielasma himalayanum Bittner. ENE of Phopa, loc. F 79 (1973). Collection of the Geologische Bundesanstalt Wien (Museum) [GBW(M)] no. 1975/03/03. a - c: dorsal, lateral and anterior views; x 2. Fig. 2

Spirijerina stracheyi (Salter). ENE of Phopa. loc. F 79 (1973J. GBW(M) no.

1975/03/08. Delthyrium and ventral interarea; > 2.

Fig. 3 - Dielasma himalayanum Bittner. ENE of Phopa, lac. F 79 1197:]). GBW(M I no. 1975/03/02. a - c: dorsal, lateral and anterior views; x 2. Fig. 4 - Austriellula tuchsi sp. n. Holotype. E of Ghyallong Rauna Lekh, loc. F 101 GBW(MI no. 1975/03/]:1. a - c: dorsa" lateral and anterior views; x 2.

(19~·:».

Fig. 5 - « Spiriterina» aff. orophila Diener, SW of Bi,ior, loc. F 142 (197:3J. GBW(M) no. 1975/03/18. a - c: dorsal, lateral and anterior views; x 2. Fig. 6 - Austriellula tuchsi sp. n. E of Ghyallong Rauna Lekh, 10(;. F 101 (1973), GBWIl\I) nu. 1975/03/14. a - c: dorsal, lateral and anterior views; X 2. All specimens (Pl. 19-21) were coated with ammonium chloride before photographing Photographs by Mrs. M. Paralov8..

M.

SIBLIK -

Triassic Brachiopods from Nepal

Riv. It. Pal., v. 81 - Tav. 19

156

M. Siblik

PLATE 20

Fig. 1 . Spirijerina stracheyi (Salter). ENE of Phopa, loc. F 79 (1973). GBW(M) no. 1975/03/12. a - c: dorsal, lateral and anterior views; x 2_ Fig. 2 - Spiri/erina stracheyi (Salter). ENE of Phopa, loco F 79 (1973). GBW(M) no. 1975/03/10. a - c: dorsal, lateral and anterior views; x 2. Fig. 3 - Spirijerina stracheyi (Salter). ENE of Phopa, loco F 79 (1973). GBW(M) no. 1975/03/09. a - d: dorsal, poster6-dorsal, lateral and anterior views; x 2

M.

SIBLIK -

Triassic Brachiopods trom Nepal

Riv. It. Pal., v . 81 - Tav. 20

158

M. Siblik

PLATE 21

Fig. 1 - Spirigerellina stoliczkai (Bittner). ENE of Phopa, loco F 79 (1973). GBW(M) no. 1975/03/05. a - c: dorsal, lateral and anterior views; x 2. Fig. 2 - Spirigerellina stoliczkai (Bittner). ENE of Phopa, loco 79 (1973). GBW(M) no. 1975/03/07. a - b: dorsal and lateral views; x 2. Fig. 3 - Spirigerellina stoliczkai (Bittner). W of Yanjar Gompa, loco F. 126 (1973). GBW(M) no. 1973/03/04. a: pedicle valve, x 2; b: detail of fig. a, x 5. Fig. 4 - ? Pexidella afL hunica (Bittner). E of Ghyallong Rauna Lekh, loco 101 (1973). GBW(M) no. 1975/03/17. a - c: dorsal, lateral and anterior views; x 2. Fig. 5 - Koeveskallina koeveskalyensis spitiensis (Stoliczka). W of Yanjar Gompa, loco F 126 (1973). GBW(M) no. 1975/03/15. a - c: dorsal, lateral and ventral views; x 2.

M.

SIBLIK -

Triassic Brachiopods from N epal

Riv . It . Pal. , v. 81 - Tav. 21