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Chapter 91. Records of the late Carboniferous ostracods from Jingyuan, Gansu, northwestern China

Chapter 91. Records of the late Carboniferous ostracods from Jingyuan, Gansu, northwestern China

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1294



c. G . SHI AND z. w.LI

Conformity

Jingyuan Formation

Upper section: Grey-black and black sandy shales, with intercalated grey-black limestones,

shales and coal seams, 73 m thick, yielding Roundyella simplicissima (Knight) and Waylandella sp.



Lower section : Grey-black and black shales, grey-white medium-and he-grained sandstones, 29 m thick.

Conformity

Bottom

Underlying Strata:

Lower Carboniferous

Yushuliang Formation-grey-white sandstones, grey-black and black-grey shales, sandy

shales, with intercalated black limestones, thin coal seams and thin-bedded gypsum.

The ostracods contained in the above-mentioned strata are mostly new species, the majority of

which are close to those from the Carboniferous of the U.S.A. and Canada. Cribroconchajingyuanensis sp. nov. is similar to C. triqueta Green from the lower Mississippian of Alberta, Canada;

Knoxina (Paraknoxina) gansuensis n. sp. is very close in lateral outline to K.(K.)texana from the

Upper Pennsylvanian of Texas, U.S.A., the character of abrupt convergence in the posterior

quarter being reminiscent of K. (K.) injlata Croneis and Gale from the Upper Mississippian of

Illinois; Cryptobairdia hongtuwaensis n. sp. approaches C. folgeri (Kellett) from the Upper

Pennsylvanian of Oklahoma, U.S.A. In the present fauna two known species, Roundyella

simplicissima (Knight) from the Jingyuan and Taiyuan Formations and Pseudobythocypris

pediformis (Knight) from the Taiyuan Formation are of particular age significance. The former

was first found in the Pennsylvanian of Missouri, U S A . Since then, most have been reported by

subsequent researchers from the Upper Carboniferous of the U.S.A. and Spain. None have so far

been reported from the lower Carboniferous. P. pediformis is a Pennsylvanian species from Kansas

and Missouri, U.S.A. and the Upper Carboniferous of Spain. Judging from the above data, strata

containing these ostracods should be assigned to the Upper Carboniferous and may be more or

less compared with the Pennsylvanian of North America.



DESCRIPTION

Order PALAEOCOPIDA

Henningsmoen, 1953

Suborder BEYRICHICOPINA

Scott, 1961

Superfamily KIRKBYACEA

Ulrich and Bassler, 1906

Family SCROBICULIDAE

Posner, 1951

Genus ROUNDYELLA

Bradfield, 1935

ROUNDYELLA

SIMPLICISSIMA (Knight, 1928)

(Pl. 2, Figs. 10, 11)

Amphissites simplicissima KNIGHT,

1928, p. 266, pl. 32, figs. lla-d, pl. 34, fig. 6.

Roundyella simplicissima, BRADFIELD,

1935, p. 66; COOPER,

1946, p. 108, pl. 17, figs. 29-36; SOHN,1961,



PLATE1-Figs. 1,2. Cryptobuirdia hongtuwuensisn. sp. la, b,right and dorsal views of carapace. Holotype, Cat.

No. Jc20411, ~ 6 3 2a,

; b, right and dorsal views of carapace. Paratype, Cat. No. Jc20412, ~ 6 3 Figs.

.

3,4.

Knoxiellu normulis n. sp. 3a, b, left and dorsal views of carapace (right valve damaged anteriorly). Holotype,

Cat. No. Jc20311, ~ 6 3 4a,

; b, left and dorsal views of carapace (right valve damaged posteriorly). Paratype,

Cat. No. Jc20312, x63.



1295



1296 C. G. SHIAND Z. W. LI

pp. 150, 151 ; SANCHEZ

DE POSADA,

1977, p. 417, pl. 3, figs. 4, 5 ;

2, fig. 2; pl. 3, figs. 3, 4.



BECKERand MAIN,

1982, p. 326, PI.



Measurements.-(,urn)

Type

Plesiotype

Plesiotype



Horizon.-The

Formation.



Cat. No.

Jc20111

Jc20112



L.

550



680



H.

340

430



W.



-



upper section of the Jingyuan Formation and the basal part of the Taiyuan

Superfamily KLOEDENELLACEAE

Ulrich and Bassler, 1908

Family BEYRICHIOPSIDAE

Henningsmoen, 1953

Genus KNOXINA

Coryell and Rogatz, 1932



Discussion.-When establishing the genus Knoxina, Coryell and Rogatz (1932 : 283) pointed out

that in addition to the characters of shell outline and surface ornamentation, another character is

“left valve overlapping the entire margins of the right except dorsal margin.” At the same time as

Coryell and Rogatz described the four species with the left valve larger than the right, they assigned

Jonesina texana to Knoxina texana. Since then, some researchers have also established new species

based on the relative size of the two valves. The species founded by Upson (1933), Croneis and

Gale (1939) were also based on the left valve being larger than the right. When establishing

Knoxina rogatzi, Croneis and Gukte (1939) pointed out that the two valves of their new species

were equal or subequal in size, but did not indicate which valve was the larger. It was Green

(1963) who established two new species in which the right valve was the larger.

The writers observe that the shell outline (shape) and ornamentation as well as other characters

of the ostracods obtained from Jingyuan (including the lower Carboniferous forms) have the

essential characters of the genus Knoxina, but their right valves are all larger than their left. Except

for Knoxina rogatzi which has equal-sized valves, all other species of Knoxina have the left valve

larger than the right or vice versa. The different overlaps of the two valves are of importance in the

classification of genera. Thus, the writers suggest that based on the difference in size of the two

valves, Knoxina may be subdivided into two subgenera, namely, Knoxina (Knoxina) and Knoxina

(Paraknoxina) n. subgen.

Subgenus KNOXINA

Coryell and Rogatz, 1932

Type species.-Knoxina (Knoxina) lecta Coryell and Rogatz, 1932

Diagnosis.-Carapace subquadrate to truncately ovate in lateral view; dorsal margin straight;

trilobate; with a parallel ventral marginal ridge. Left valve larger, overlapping the right all



PLATE2-Figs. 1 2. Waylandellasp. 1, lateral view of technomorphic right valve inside-mould. Described specimen,

Cat. No. Jc20621, x 63; 2, lateral view of technomorphic right valve inside-mould. Described specimen, Cat,

No. Jc20622, x 63 ; Figs. 3a, b. Cribroconcha jingyuunensis n. sp. right and dorsal views of carapace (right valve

damaged posteriorly). Holotype, Cat. No. Jc20511, x63. Figs. 4,5. Waylandella informa n. sp. 4a-q right, dorsal and left views of carapace. Holotype, Cat. No. Jc 20611, x63; 5 , right view of carapace. Paratype, Cat. No

Jc 20612, ~ 6 3 Figs.

.

6,7. Pseudobythocypris pediformis (Knight). 6a, b, right and dorsal views of carapace.

Plesiotype, Cat. No. Jc20711, ~ 6 3 7,

; right view of carapace. Plesiotype, Cat. No. Jc 20712, ~ 6 3 Figs.

.

8a, b.

Knoxina (Paruknoxina) gansuensis subgen. n. sp. left and dorsal views of carapace. Holotype, Cat. No. Jc20211,

x 63. Figs. 9a, b. Knoxina (Purdcnoxinu) subovata subgen. n. sp. left and dorsal views of carapace. Holotype,

Cat. No. Jc20221, x63:Figs. 10, 11. Roundyella simplicissima (Knight). 10, lateral view of technomorphic

left? valve inside-mould. Plesiotype, Cat. No. Jc20111, x63; 11, lateral view of technomorphic left? valve.

Plesiotype, Gat. No. Jc20112, x 63.



around the free margin, most strongly at the ventral margin. Surface ornamented with fine

tubercles or reticulations. Elliptical or cuneiform in dorsal view.

This subgenus Knoxina (Knoxina) includes the following species: Knoxina (Knoxina) elriptica

Coryell and Rogatz, 1932, Knoxina (Knoxina) incurvatu Coryell and Rogatz, 1932, Knoxina

(Knoxina) inflata Croneis and Gale, 1932, Knoxina (Knoxina) nebruskensis Upson, 1939, Knoxina

(Knoxina) texana (Harlton, 1929).

Subgenus PARAKNOXINA

n. subgen.

Type species.-Knoxina (Paraknoxina) gansuensis n. subgen., n. sp.

Diagnosis.-Except that the right valve is larger than the left, characters are the same as for

Knoxina (Knoxina).

This new subgenus, Knoxina (Paraknoxina), is here proposed to include the following species:

Knoxina (Paraknoxina) costata Green, 1963,Knoxina(Paraknoxina)marginata Green, 1963, Knoxina

(Paraknoxinu) gansuensis n. sp. and Knoxina (Paraknoxina) subovata n. sp.

KNOXINA

(PARAKNOXINA)

GANSUENSIS n. subgen., n. sp.

(Pl. 2, figs. 8a, b)

Description.-Carapace truncately ovate in lateral view ; dorsal margin straight and long;

anterior end higher than the posterior; the upper parts of both ends united with dorsal margin

form equally obtuse angles; ventral margin evenly convex. Greatest height near the centre. Greatest

length near the mid-line. S1 short and shallow; S, deep, wide and connected with a pit at its lower

end. L1 rounded, parallel to ventral margin from the midventral, developing into a wing-like

ridge in a posterior direction to the mid-posterior part. Surface granulated. Cuneiform in dorsal

view, strongly compressed in the posterior quarter of the length which gives a concave outline to

each valve, delimitting the posterior caudal process. The middle and the anterior quarter concave.

Right valve larger, overlapping the left all around the free margin.

Measurement.--(,urn)

Type



Cat. No.



L.



Holotype



Jc20211



920



H.

530



W.

400



Discussion.-This new species and the lower Mississippian Knoxina (Paraknoxina) costata Green

(1963: 106, P1. 4, figs. 21, 22) from the northwestern terrace of Banff in Alberta of Canada as well

as Knoxina (Paraknoxina) marginata Green (1963: 107, P1. 5, figs. 1-6) all have the same type of

overlap in that the right valve is larger than the left. K. gansuensis differs from the other two species, however, in its cuneiform dorsal view and the sharp compression in the posterior quarter of its

length. The new species is similar in lateral view to the Upper Pennsylvanian Knoxina (Knoxina)

texana Coryell and Rogatz (Harlton, 1929: 146, P1. 1, fig. 14) from Texas and in its sharp posterior

compression the new species is reminiscent of the Upper Mississippian Knoxinu (Knoxinu) inflata

Croneis and Gale (1939: 266, P1.6, figs. 17, 18) of Illinois. The chief difference lies in the larger right

valve of the new species and the larger left valve of the other two.

Horizon.-The upper section of the Yanghugou Formation.

KNOXINA

(PARAKNOXINA)

SUBOVATA n. subgen. and sp.

(Pl. 2, figs. 9a, b)

Description.-Carapace small in size, truncately oblique-ovate in lateral view ; dorsal margin

straight and long; postiro-dorsal angle larger than the anterodorsal one. Anterior end apparently

higher than the posterior, broadly rounded, meeting the ventraI margin roundly. The upper part of



Late CarboniferousOstracodafrom Jingyuan, China 1299



the posterior end truncated, the lower meeting the ventral margin evenly. Free margin rounded in

outline, inclined forward. Greatest height at the anterior one-third and greatest length near the

mid-line. S1 short and shallow, S, deep and wide, the lower part united with a pit. L1rounded,

from the mid-ventral part parallel to the ventral margin and developing posteriorly into a winglike ridge. Surface reticulated. Elongate ovate in dorsal view, the posterior one-third converging

posteriorly. Anterior end bluntly rounded ;posterior end pointedly rounded. Curved inwards in the

middle and the anterior quarter of the length. Right valve larger, overlapping the left all around

the free margin.

Measurements.-(,urn)

Type



Cat. No.



L.



H.



W.



HolotvDe



Jc20221



600



370



290



Discussion.-This new species is distinguished from Knoxina (Paraknoxina) gansuensis n. sp.

in its dorsal and lateral outlines.

Horizon.-The upper section of the Yanghugou Formation.

Family GEISINIDAE

Sohn, 1961

Genus KNOXIELLA

Egorov, 1950

KNOXIELLA

NORMALIS n. Sp.

(Pl. 1, figs. 3a-4b)

Description.-Carapace truncately elliptical in lateral view ; dorsal margin straight and long;

anterior and posterior dorsal angles subequal. Anterior end higher than the posterior, broadly

rounded and slightly inclined downward. Posterior end narrowly rounded and inclined upward.

The middle part of the ventral margin nearly straight, broadly rounded at the anterior and inclined

upwards in its posterior part. Greatest height in the middle and greatest length near the midline.

Nearly straw sandal-shaped in dorsal view, concave in the middle part. Hinge groove slender.

Anterior and posterior ends of the right valve overreaching the left valve. Greatest thickness in

the posterior one-third. S1 short and shallow, sometimes inconspicuous. S, deep and long, with a

faintly visible rounded node in the front. Surface reticulated. Right valve larger, overreaching and

overlapping all a round the free margin of the left.

Measurements.-(,urn)

Type



Cat. No.



L.



H.



W.



Holotype

Paratype



Jc2031 1

Jc20312



1060

1100



600

650



440

430



Discussion.-K. normalis is distinguished from Knoxiella ischimensis Polenova (1953 : 49, P1. 4,

figs. 5,6) from the Upper Devonian of the U.S.S.R. in that the right valve of the latter overreaches

the left valve dorsally. Roundly oblong in lateral view with a smooth surface.

Horizon.-The upper section of the Yanghugou Formation.

Order PODOCOPIDA

Muller, 1894

Suborder PODOCOPINA

Sars, 1866

Superfamily BAIRDIACEA,

Sars, 1887

Family BAIRDIIDAE

Sars, 1887

Genus CRYPTOBAIRDIA

Sohn, 1960

CRYPTOBAIRDIA

HONGTUWAENSISn. sp.

(Pl. 1, figs. la-2b)

Description.-Carapace



nearly rhomboidal in lateral view; dorsal margin arched; anterodorsal



margin straight, with the lower part inwardly concave. Anterior end rounded. Posterior beak

conspicuous, and lying a little below the midline. The middle part of the ventral margin slightly

concave, anterior and posterior parts inclined upward. Greatest thickness in the anterior one-third.

Fusiform in dorsal view, thickest in the middle. Left valve larger, almost completely overlapping

the free margin and the hinge area more or less overreaching the right valve. The overlapping

areas on the antero- and postero-dorsal margins and the ventral margin are relatively wide.

Surface granulated or pitted.

Measurements.-(pm)

Type



Cat. No.



L.



H.



Holotype

Paratype



Jc20411

Jc20412



1160

1170



600

630



W.

500

480



Discussion.-This new species is similar to the Upper Mississippian Cryptobairdia folgeri

(Kellett, 1934: 136, P1. 18, figs. 1, 4: 19, figs. 1, 4, 6) from Oklahoma, but differs from the latter

in its sloping anterodorsal margin and in its smooth surface.

Horizon.-The basal part of the Taiyuan Formation.

Suborder METACOPINA

Sylvester-Bradley, 1961

Superfamily HEALDIACEA

Harlton, 1933

Family HEALDIIDAE

Harlton, 1933

Genus CRIBROCONCHA

Cooper, 1941

CRIBROCONCHA JINGYUANENSIS n. Sp.

(Pl. 2, figs. 3a, b)

Description.-Carapace obliquely elliptical in lateral view; dorsal margin ,.mtly angulate

and curved outward. Posterior end higher than the anterior, broadly rounded. Anterior end inclined

downward and rounded. Ventral margin nearly straight. Greatest height in the middle. Greatest

length near the midline. Nearly cuneiform in dorsal view. Greatest thickness at the ridges. A grooveshaped ridge opens forward in the posterior part of the carapace, its upper part overreaches the

margin and its posterior part forms a sloping ridge. Inside the groove-shaped ridge are longitudinal

reticulations. Left valve larger, overlapping the right all around the free margin.

Measurements.-bm)

Type

Holotype



Cat. No.

Jc205 1 1



L.

700



H.

400



W.

330



Discussion.-In dorsal view C. jingyuanensis resembles the lower Mississippian Cribroconcha

triquelia Green (1963: 161, P1. 13, figs. 17-20)from northern Jasper, Canada, but the latter differs

in that its dorsal margin is strongly arched in lateral view and the anterior end is lower than the

posterior, the surface is covered by coarse, sparse reticulation and the arched posterior ridge does

not over-reach the dorsal margin.

Horizon.-The upper section of the Yanghugou Formation.

Genus WAYLANDELLA

Coryell and Billings, 1972

WAYLANDELLA

INFORMA n. sp.

(Pl. 2, figs. 4a-5)

Description.-Carapace nearly elliptical in lateral view ; dorsal margin evenly convex. Posterior

end rounded, higher than the anterior. Anterior end rounded and inclined downward. The middle

part of the ventral margin slightly concave. Greatest height in the middle. Greatest length near the

middle. Posteroventral corner of right valve with a tubercle; posteroventral corner of left valve



Late Carboniferous Ostracodafrom Jingyuan, China 1301



with only a slight swelling. Left valve larger, overlapping the right all around the free margin.

Surface smooth.

Measurements.-(um)

Type



Cat. No.



Holotype

Paratype



Jc20611

Jc20612



L.

560

560



H.

320

320



W.



250

300



Discussion.- Waylandella informa n. sp. differs from the other species of WayIandeIIa in being

slightly swollen at the posteroventral corner of left valve and in having a tubercle at the posteroventral corner in the right valve.

Horizon.-The basal part of the Taiyuan Formation.

WAYLANDELLA

sp.

(Pl. 2, figs. 1-2)

Description.-Reniform in lateral view ; dorsal margin evenly convex. Posterior end higher than

the anterior, obliquely rounded. Greatest height in the middle or behind the middle. Greatest length

near the midline. There is a spine on the posterodorsal part of the valve and an inconspicuous

tubercle near the posteroventral angle.

Measurements.-(pm)

Type

Described

specimen

Described

specimen



Cat. No.

Jc20621



L.

620



H.



W.



330



-



Jc20622



620



330



-



Discussion.-The specimens described herein are close in lateral view to WayIandeIIa dartyensis

(Benson and Collinson, 1958: 9, P1. 1, figs. 4-6) from Missouri, U S A . W. dartyensis. however, is

distinguished by its prominent posteroventral spines and its lack of a posteroventral tubercle.

As the present specimens are only inner moulds, they are not given a specific name.

Horizon.-The upper section of the Jingyuan Formation.

Family BAIRDIOCYPRIDIDAE

Shaver, 1961

Genus PSEUDOBYTHOCYPRIS

Shaver, 1958

PSEUDOBYTHOCYPRIS

PEDIFORMIS (Knight, 1928)

(Pl. 2, figs. 6a-7)

Bythocypris pediformis KNIGHT,

1928, p. 326, 328, PI. 44, fig. 3.

Pseudobythocypris pediformis, SHAVER,

1958, p. 122-124; SANCHEZ

DE POSADA,

1977, p. 423, PI. 5,

figs. 5-9.



Discussion.-Except that a few are smaller, wider and have a blunt posteroventral angle, the present specimens have the same chief characters as those of Bythocypris pediformis described by

Knight (1928) from the Pennsylvanian of Missouri, U.S.A. Their adductor muscle scars are faintly

visible and consist of many minute scars forming a round scar group.

Measurements.-(um)

Type

Plesiotype

Plesiotype



Horizon-The



Cat. No.

Jc20711

Jc20712



L.

550

510



basal part of the Taiyuan Formation.



H.

300

270



W.

220

210



1302



c. G. SHI AND z. w.LI



REFERENCES

BECKER, G. 1982. Fazies-anzeigende Ostracoden-Vergesellshaftungen

aus dem fruhen Oberkarbon des Kantabrischen



Gebirges (N-Spanien) N. Jb. Geol. Palaont. Abh., 164 (3), 307-338.

and COLLINSON, c., 1958. Three Ostracode faunas from Lower and Middle Mississippian strata in

southern Illinois. Illinois. Geol. Surv. Circ., no. 225, 26 pp.

BRADFIELD, H.H. 1935. Pennsylvanian Ostracoda of the Ardmore Basin, Oklahoma. Bull. Am. Paleont., 22

(731,173 PP.

COOPER, C.L. 1946. Pennsylvanian Ostracodes of Illinois. Bull. Illinois State Geol. Surv., no. 70, 177 pp.

CORYELL, H.N. and ROGATZ, H. 1932. A study of the ostracode fauna of the Arroyo formation, Clearfork group of the

Permian in Tom Green County, Texas. Am. Midland Natural., 13 (6), 378-395.

CRONEIS, c. and GALE, A.S. m. 1938. New ostracodes from the Golconda Formation. Deninson Univ. Bull., 33,

251-296.

- and GUTKE, R.L. 1939. New ostracodes from the Renault Formation. Zbid., 39, 33-63.

GREEN, R. 1963. Lower Mississippian ostracodes from the Banff Formation, Alberta. Res. council Alberta Bull.. no.

11,237 pp.

HARLTON, B.H. 1929. Pennsylvanian Ostracoda from Menard county, Texas. Texas Univ. Bull. 2901, 139-161.

KNIGHT, J.B. 1928. Some Pennsylvanian ostracodes from the Henrietta formation of eastern Missouri. J. Paleonr.

2, (3-4), 229-267, 318-336.

WLENOVA, E.N. 1953. Ostracoda of the Devonian deposits in the Central Devonian Field and the Middle Volga region (Russian). All-Union Petrol. Sci. Res. Geol. Prospect. Znst. (VNIGRI), n.s.no. 68, 155pp.

SANCHEZ DE POSADA, L.C. 1977. Ostracodes from the Upper Carboniferous of la Camocha Coal Mine (Asturias, N.

Spain). Rev. ESP. Micropaleontol., 9(3), 41 1-438.

SHAVER, R.H. 1958. A study of Pseudobythocypris pediformis. a new name for an old ostracod. Am. Midland Nut..

59 (l), 120-137.

SOHN, 1.0.1960. Paleozoic species of Bairdia and related genera. US.Geol. Surv. Prof: Paper, 330-A, 105 pp.

- 1961. Aechminella, Arnphissites, Kirkbyella, and related Genera. Ibid., 330-B, 107-160.

UPSON, M.E. 1933. The Ostracoda of the Big Blue Series in Nebraska. Nebraska, Geol. Bull., 8, ser. 2, 54 pp.

BENSON, R.H.



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Chapter 91. Records of the late Carboniferous ostracods from Jingyuan, Gansu, northwestern China

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