Non-Marine Ostracod Biogeographical Regions of the Early Cretaceous In

ZOBODAT - www.zobodat.at

Zoologisch-Botanische Datenbank/Zoological-Botanical Database

Digitale Literatur/Digital Literature

Zeitschrift/Journal: Zitteliana - Abhandlungen der Bayerischen Staatssammlung für Paläontologie und Histor. Geologie

Jahr/Year: 1982

Band/Volume: 10

Autor(en)/Author(s): Chun-Hui Ye

Artikel/Article: Non-marine Ostracod biogeographical regions of the early Cretaceous in China 395-398 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 395

Zitteliana 10 395-39S München, 1. Juli 1983 ISSN 0373-9627

Non-marine Ostracod biogeographical regions of the early Cretaceous in China

By YE CHUN-HUI*)

With 1 text figure

ABSTRACT

The investigations of the non-marine ostracods of the early fauna in the province of North China can be related to those Cretaceous in China (predominantly representatives of the of Central Sibirian region and Mongolia. The province of superfamily Cypridacea) permit a subdivision into two large South China reveals interconnexions with the Centralasia- paleobiogeographical regions, each of which can be divided tic-Southrussian province. A warm, subtropical climate is again into three subregions. The assemblages of these regions suggested for both provinces. are characterized. In addition to numerous endemic forms the

KURZFASSUNG

Die Untersuchungen der nicht marinen Ostrakoden der mischen Formen zeigen die Faunen in der nordchinesischen Unterkreide in China (meistens Vertreter der Uberfamilie Provinz Beziehungen zur mittel-sibirischen Region und zur Cypridacea) gestatten eine Einteilung in 2 große palaeobio- Mongolei, während die südchinesische Provinz Gemeinsam geographische Regionen in denen jeweils wieder 3 Unterre keiten mit der mittelasiatischen-südrussischen Provinz auf gionen ausgeschieden werden. Die Vergesellschaftungen die weist. Für beide wird ein warmes, subtropisches Klima disku ser Unterzonen werden charakterisiert. Neben vielen ende tiert.

I. EARLY CRETACEOUS NON MARINE OSTRACOD ASSEMBLAGE AND BIOGEOGRAPHICAL REGIONS IN CHINA

Between the late Jurassic and late Cretaceous, there were na, Tarim Basin of Xinjiang, Qinghai, Zhejiang, the south of about 30 genera and 350 species of non-marine ostracodes in Anhui and Jiangsu. continental sediments over most of the territory of China. The North China region is characterized by the high diver Most of them fall into superfamily Cypridacea except a few sity of complex-ornamented Cypridea and the presence of which are involved in superfamily Cytheracea. The early Cre genera Mongolianella, Luanpingella, Zonocypris and Can- taceous non-marine ostracod fauna is widely distributed in dona throughout the early Cretaceous and it may be separa two different biogeographical regions: The North China and ted into the Innerland Area (R) and the Circulated-Pacific The South China regions, with the Mts. Tianshan, Qilian, Area (I2). Qinling, Wuniu and Dabei as their borderland. In geography the former includes North-Eastern China, Northern China, The South China region differs from the North China re Shandong, Shanxi, Shaanxi, Inner Mongolia, Ningxia, Gan gion in the appearance of Jingguella, Monosulcocypris and su, Zhungeer Basin of Xinjiang and the north of Jiangsu, An Pinnocypridea; the genus Cypridea in this region carries hui. The latter covers South-Central and South-Eastern Chi simple ornaments. Based on the endemic species, it may be divided into the Borderland area of Mediterranian (II3), the

*) Ye C hun-HUI, Institute of Geology and Palaeontology, Acade Innerland area (1I2) and the Circulated-Pacific area (Hi), (see mia Sinica, Chi-Ming-Ssu, Nanjing, China. fig. 1). 396 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

A. The early Cretaceous non-marine ostracodes of the Anhui and its equivalent continental deposits in Central Asia, South China region can be separated into three ostracod as USSR. semblages: 2. The Cypridea-Mongolianelhi-Darwinula assemblage is 1. Jingguella-Pinnocypridea-Darwinula assemblage of the middle early Cretaceous ostracod fauna of the South early Cretacous; China region. Among the main characters of this ostracod as 2. Cypridea-Mongolianella-Darwintda assemblage of semblage are the simple ornaments of Cypridea and a moder middle early Cretaceous; ate number of Darwinula, Rhinocypris, Zizipbocypris and 3. Cypridea (Monma) - C. (Bisulcocypridea)-Monosidco- Damonella. Of great significance determining the age of this cypris assemblage of late early Cretaceous. ostracod assemblage is the frequent appearence of Cypridea 1. The Jingguella-Pinnocypridea-Darwinula assemblage is (Ulwellia) paulsgrovensis A nderson, C. (U.) minevensis characterized by the appearance of great number of JingguelLi A nderson which are the important members of ostracod as including many subgenera, such as JingguelLi (Jingguella), J.semblages of Wadhurst Clay (middle Valanginian) in Eng (Minheella) , J . (Jiangenia) and a number of Darwinula, Da- land. According to the data above, this ostracod assemblage is monella, Pinnocypridea and Cypridea which are in posses referred to middle early Cretaceous in age and it is considered sion of faint beak and notch. The age of the ostracod assem to be equivalent to Valanginian to Barremian in Western Europe. blage is supposed to be early early Cretaceous, corresponding to the Berriasian of Western Europe, and also probably late Most typical strata that contain the second ostracod assem Portlandian. blage is the Puchanghe formation of Yunnan. The other for The Chengqiangyan Group of Sichuan within the Border mations that contain individual elements of them are the Gu- land area of Mediterranian of the South China region is a typi dian formation of Sichuan; the lower subgroup of Hekou cal bed that contains the first ostracod assemblage. The other Group of Minhe Basin, Qinghai and the upper part of Shou- formation containing this ostracod fauna is the lower part of chang formation from Zhejiang. The first and the second Qiapushaliang formation of Tarim Basin, Xianjiang; the Da- ostracod assemblages have not been discovered so far in the tonghe formation of Minhe Basin, Qinghai; the Jinxing for Innerland area of the South China region. mation of Lanping-Simaoo district and the Gaofengshi for 3. Cypridea (Morinia) - C. (Bisulcocypridea) - Monosulco- mation of Chuxiong district, Yunnan. With the exception of cypris assemblage is the late early Cretaceous ostracod fauna these, there are individual elements of the first ostracod as in the South China region which is characterized by Cypridea semblage to be found in the Yuantang formation of Southern (Morinia) associated with Cypridea (Bisulcocypridea) which © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 397 is the common member of late early Cretaceous (Aptian to blage is the earliest non-marine ostracod fauna of the Cretace Albian) non-marine ostracods all over the country. In addi ous in the North China region and is considered to be con tion, there is higher development of small carapace forms of temporaneous with the first ostracod assemblage of the South Darwinula and of genus Monostdcocypris which is widely di China region. stributed in the red beds of the South China region. 2. Unlike the first ostracod assemblage of early Cretaceous The widespread late early Cretaceous ostracod assemblage the Cypridea-Yumenia-Mongolianella assemblage is charac can be compared with each other in the South China region terized by the high diversity of forms and the complex-orna where the endemic species came into existence especially in mentations in Cypridea. In addition to Cypridea (Cypridea), the Innerland area (II). there are Cypridea (Morinia), C. (Ulwellia), C. (Cyamocyp The strata containing this ostracod assemblage are the Ma- ris), C. (Bisulcocypridea) and Yumenia (including to Cypri toushan formation and Mangang formation of Yunnan; the dea (Yumenia) before). The Diwopu formation or Xiagou upper subgroup of Hekou group, Minhe Basin of Qinghai; formation of Ganxu is a typical bed in the North China region the Qijiahe formation and Dongjing formation of Hunan; which has a lot of such ostracod faunas. The other equivalent Ningxiang formation of Hubei; Huizhou formation of Sou formations of the North China region are the Jiufutang for thern Anhui; Huoko formation of Fujian and Guantou for mation of Western Liaoning, the Guyan formation of Inner mation of Zhejiang. Mongolia, the upper part of the Zhidan group of Ertoushi has It is worth mentioning that an important ostracod assem the some ostracod fauna but the individual elements of them blage which is characterized by Cypridea (Morinia) associa may be absent in some formations. ted with Monostdcocypris is usually present in the lower part It should be noted that some species of Cypridea in the se of some strata, such as the lower part of Huizhou formation cond ostracod assemblage are similar to those of England, and the Hengshan formation. i. e. Cypridea koskulensis resembles Cypridea bogdensis, B. The early Cretaceous non-marine ostracodes of the Cypridea setina gansuensis Y e is similar to Cypridea setina North China region can also be divided into three ostracod as A nderson, Cypridea changmaensis Y e is similar to Cypridea semblages: dolobrata angulata M artin, Cypridea (Bisulcocypridea) sub- 1. Cypridea-Luanpingella-Eoparacypris assemblage; chuxiongensis Y e to Cypridea (Bisulcocypridea) frithwaldi 2. Cypridea-Yumenia-Mongolianella assemblage; A nderson. All of these English species of Cypridea occur in 3. Cypridea-“Lycopterocypris”-Mongolocypris assem bla Valanginian to Barremian stage of Lower Cretaceous. On this ge- base, the second ostracod assemblage should be refered to the 1. The Cypridea-Luanpingella-Eoparacypris assemblage middle early Cretaceous in age and may be equivalent to the contains a poor number of Cypridea which has complex or Valanginian to Barremian stages of Western Europe. naments and only a few kinds ofCypridea (Cypridea) and 3. The Cypridea-“Lycopterocypris”-Mongolocypris as C. (Cyamocypris) are present. In addition, genus Luanpin- semblage is the late early Cretaceous fauna in the North China gella is an important member in this ostracod assemblage. region. The character of this ostracod assemblage is allied to The Dabeigou formation of Northern Hebei and the Che- the third ostracod assemblage of the South China region in the jinpu formation of Ganxu are of typical Cypridea-Luanpin- appearence of Cypridea (Morinia) associated with Cypridea gella-Eoparacypris ostracod assemblage. The ostracod faunas (Bisulcocypridea). However because of the presence ofZono- of the other equivalent strata in the North China region are cypris, Candona and a great number of Mongolocypris, it may more or less distinct from them. be able to differentiate from the South China region. It is particularly significant that Eoparacypris jingshanensis The strata containing the third ostracod assemblage are the Y ang and Cypridea sulcata M andelstam of the Dabeigou Zhonggou formation of Gansu, the upper part of Liupanshan formation are very similar to Eoparacypris macroselina A n group, Ningxia; the upper part of Qingshan formation, derson and Cypridea bimammata (H arbort) in the Berria- Shandong; Sunjiawan formation of western Liaoning; the lo sian stage of Southern England. For this reason, it is justifiable wer part of Songhuajiang group, Songliao Plaint and Dalaji to say that the Cypridea-Eoparacypris-Luanpingella assem formation and Tongfushi formation of Yianjia district, Jiling.

II. PROBLEMS AND DISCUSSION

1. The early and middle early Cretaceous non-marine region of USSR are of the same ostracod biogeographical pro ostracod fauna of the North China region is similar to the vince which is the transition between the North Circum-Po- ostracod assemblages of Mongolia, the East Asian region and lar Province and the South Circum-Polar Province. the Middle Siberian region of USSR and the Circum-polar During the late early Cretaceous, the ostracod assemblages belt of Europe (A nderson, 1973),that means the North Cir- of both regions has their own endemic species, but the resem cum-Polar Province. blance between the North China region and the South China The non-marine ostracod fauna of the South China region region as shown in Cypridea (Morinia) associated with Cy resembles the ostracod fauna of Middle Asian region of pridea (Bisulcocypridea) is an important character which is USSR. Both remain to have Asian endemic character. It seems commonly seen from Lebanon, Turkman of USSR, the USA, that the South China region of China and the Middle-Asian England and Congo, that is the North and the Sopth of the 398 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at circum-polar belt (A nderson, 1973). For this reason, it can gion may be of nearly sub-tropical character, as A nderson not be stated with certainty whether the endemic species of thought to be, with more or less wet climate. both regions at this age arc characteristic enough to separate During the early early Cretaceous red beds dominated all China into the North China region and the South China re over most of the South China region. The ostracod fauna of gion or wether the whole China belongs to only one ostracod this region hears the character of Asia-endemic species. Some hiogeographical region. of them occur recently in South Africa and Southern Brazil. 2. The border line between the North China region and the On the other hand, the genus C.ypridea is not so frequent in South China region should he designated the direction of pa- this region and carries simple ornamentation. All of this seem leo-latitutc. If this assumption is correct the North-polar of to show that it is nearly sub-tropical with dry and hot climate. Cretaceous would be situated in the area Eastward to the pre sent North-polar, while the South-polar would be at the west In middle early Cretaceous of the same region, there are to the present South-polar. many light-colour deposits alternating with red beds and the ostracod fauna of the South China region has some Asian en 3. The distribution of early Cretaceous non-marine ostra demic species, but some species of Cypridea are similar to cod fauna may he connected with the temperature-climatic those in England. On the basis of selected data discussed ab zones. During the early and middle early Cretaceous, the ove, the climate of the South China region at this time may he North China region was connected with the Northern cir sub-tropical, alternating dry with wet climate. cum-polar belt (A nderson, 1973). It is situated in the same paleo-latitude and has a high diversity of complex-ornamen During the late early Cretaceous, it is not known whether ted Cypridea. A nderson (1973) stated that the climate of the both of the North China and the South China regions may be C.ypridea belt was similar to that which is now found in the long to northern circum-polar belt of A nderson (1973) or Southern Mediterranean-North African area and it was a not. The presence of widespread red beds and of the genus nearly sub-tropical climate. Accordingtothedevelopment of Zonocypns which is a living genus of Africa may indicate that light-colour deposits and of coalbearing beds and in addition the climate of both regions was hotter and drier i. e., nearly a to the palynological data, we suggest that the North China re sub-tropical climate.

REFERENCES

ANDERSON, l;.W. (1973): The Jurassic-Cretaceous transition: the Ye Chun IIUI el al. (1977): Mesoz.oic-Cenozoic Ostracod fauna non-marine Cfstracod fauna. - In: The Boreal I.ower Cretace from Yunnan in “Mesozoic Fossil From Yunnan” Part 11. — ous, CASEY, R. and R aw so n , I’. E. (Eds.). Gcol. Journ. Spe Science Press. cial Issue, 5, Liverpool. ------(1979): The Cretaceous Ostracod assemblages from Zhejiang, A ndreev, Yu. N. & M andi.i stam , M. 1. (1971): Biogcographical Anhui and adjacent region in “Mesozoic and Cenozoic red associations of Cretaceous Ostracods in the USSR. - Collo beds of South China” - Collection of Papers from the “Field quium on the Palcoecology of Ostracods. - fl. J. OERTEI conference of the Cretaceous Tertiary red beds from South (cd.), pp. 615-630. China” at Nanxiong, Guandong. Science Press. 11 AO Y l'CHUN et al. 1974: The Fossil Ostracodn of ( rctaceous-Tcr------et al. (1980): Jurassic-C retaccous fossil Ostracoda from Zhe liary from Songliao Plain. - Geology Press. jiang in “Division and Correlations on the Mesozoic volca I lot' Yo U-TANC, 1958: Jurassic and Cretaceous non-marine Ostra no-sedimentary formation in Zhejiang and Anhui Province, cods of the Subfamily Cyprideinac from North-Western and China. - Edited by Nanjing Inst. Gcol. Palaeont., Academia North-Eastern regions of China. - Memoirs of the Institute of Sinica, Science Press. Palaeontology, Academia Sinica. 1, Science Press, et al. (1978): The Cretaceous-Tertiary Ostracods from the marginal region by the Yangtze-Han River. - Memoirs Nan jing Inst. Geol. Paleont., Academia Sinica, 9, Science Press.