Kalligrammatid Lacewings from the Upper Jurassic Daohugou Formation in Inner Mongolia, China
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Vol. 77 No. 2 ACTA GEOLOGICA SINICA June 2003 141 Kalligrammatid Lacewings from the Upper Jurassic Daohugou Formation in Inner Mongolia, China ZHANG Junfeng Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, Jiangsu 21 0008, E-mail: [email protected] Abstract A new species, referable to a new genus, is erected, and named the Sinokalligramma jurassicum gen. et sp. nov. It is the second finding of kalligrammatids in the Daohugou Formation. The origin and migration of the family Kalligrammatidae are discussed. The geological age and stratigraphic correlation of the Daohugou and Karabastau Formations are briefly reviewed and reassessed. Key words: kalligrammatid lacewings, new taxa, age, origin and migration, Jurassic, Inner Mongolia, China 1 Introduction animal and botanic fossils to be of the known Barremian Yixian Formation (Wang et al., 2000; Wang, 2000). Later, Kalligrammatids belonging to the family they classified the rocks as the Early Cretaceous basal Kalligrammatidae within Neuroptera, Insecta are extinct, parts of the Yixian Formation or Dabeigou Formation, an specialized and large insects that lived during the underlying stratigraphic unit of the Yixian Formation Mesozoic. Up to date, twenty-one species, referable to (Wang et al., 2002). Others argued that they are of the Late eleven genera, are recognized as kalligrammatids Aalenian or Early Bajocian Jiulongshan Formation @en throughout eastern Asia, central Asia and western Europe and Oswald, 2002), or Upper Jurassic (Ji and Yuan, 2002). (Scudder, 1886; Walther, 1904; Handlirsch, 1906, 1919; On the basis of an analysis of new biostratigraphic data, Cockerell, 1928; Martynova, 1947; Panfilov, 1968, 1980; Zhang (2002) believed that fossil entomofaunas in the Ponomarenko, 1984, 1992; Janembowski, 1984, 2001; Daohugou and Karabastau Formations in Karatau, Whalley, 1988; Carpenter, 1992; Lambkin, 1994; Ren and Kazakhstan can be correlated, and they are Guo, 1996; Ren and Oswald, 2002). Some of them are contemporaneous or nearly so, belonging to the Oxfordian reassessed, and do not belong to the family or Kimmeridgian in age. Hence, a new stratigraphic unit, Kalligrammatidae. Some taxa are based on badly the Daohugou Formation, was set up. The insect preserved specimens, and their systematic position is assemblage was named the Daohugou Biota or pre-Jehol uncertain at familial, or even ordinal level (Zhang and Biota, which is earlier in age than the Jehol Biota beyond Zhang, 2003). The undoubted representatives of doubt. kalligrammatids appeared only in the Late Jurassic and It should be pointed out that the age of the Yixian Early Cretaceous, and it is uncertain that they can be Formation has been the focus of much discussion among extended into the undoubted Middle Jurassic. Heretofore, geologists and paleontologists. Some researchers regarded five species referable to three genera of kalligrammatids it to be Late Jurassic, or Late Jurassic-Early Cretaceous, or have been recorded respectively from the Yixian Early Cretaceous (Zhang, 1999; Ji. 2002; Ji et al.. 2003; Formation at Huangbanjiegou in Chaomidianzi of Beipiao. Rougier et al.. 2003). This author thought that it is to be Jiaoning Province, China (Ren and Guo, 1996) and the latest Late Jurassic-earliest Early Cretaceous based on new Daohugou Formation near Daohugou village in Shantou materials of insect fossils from Yixian Formation (Zhang, Town of the Ningcheng Area, Chifeng, Inner Mongolia, 1999; Zhang and Zhang, 2001). Despite various China (Ren and Oswald, 2002). viewpoints mentioned above, the insect assemblages in the New fossils belonging to kalligrammatids were recently Yixian and Dabeigou Formations should belong recovered from the Daohugou Formation. They are of a doubtlessly to the Jehol Biota, and younger in age than new species, referable to a new genus, within that of the Daohugou Formation, because those Kalligrammatidae. The geological age and stratigraphic researchers who regarded the Yixian Formation to be Late correlation of the Daohugou Formation are, at the present Jurassic also held that they must not be older than the time, controversial. Some researchers considered these Tithonion (Sun et al., 1998; Lo et al., 1999; Jiang et al., freshwater lacustrine sedimentary rocks that bear rich 2000, Ji, 2002; etc.). 142 Late Jurassic Kalligramrnatid from Inner Mongolia, China In the earliest articles the age of the Karabastau are most likely coeval and equivalent to the Oxfordian or Formation was given as the lower Dogger of the Middle Kimmeridgian. Jurassic, but, for several dozens years, was regarded as It is a complex and comprehensive problem to make a Upper Jurassic (Rohdendorf, 1962, 1968) or stratigraphic correlation in non-marine sedimentary rocks Kimmeridgian (Hedg, 1981) or and identify their geological ages. To carry out a study Oxfordian-Kimmeridgianof the Upper Jurassic (Zherikhin based on biostratigraphic data of various animal and and Gratshev. 1993; Mostovski 1996). Recently, however, botanic groups, an all-around investigation, analysis and some Russian paleoentomologists considered the age of deduction would be required, and there is a precondition these non-marine sedimentary rocks to be Middle or in identifying exactly the systematic positions of taxa. The uppermost Middle Jurassic to pre-Tithonian of the Upper more abundant the short-lived groups used, the more Jurassic (Rasnitsyn et al. 1998; Mostovski 1998). But, amrate the results obtained. The conclusion would be not they have not interpreted how the rocks could be Middle reliable if it is based only on very few groups, or one and or uppermost Middle Jurassic. However, many Russian two known genera and species because there are some paleoentomologists thought it to be Upper Jurassic taxa that can be attributed to longish living insects. For (Belayeva et al., 2002). It seems to be in the right that the example, a mayfly, Ephemempsis trisetalis Eichwald, Karabastau Formation is older in age than the pertains to a permanently dominant and geographically Archaeopteryx fauna from the Early T~thonian of widespread species within the Jehol Biota, and existed Solnhofen, Germany, and thus, the suggestion that the age respectively in the Dabeigou, Yixian and Jiufutang of the upper limit of the Karabastau Formation is formations in Liaoning Province, China. It is evident, pre-Tithonian is well founded. But, it is questionable however, that the latter is undoubtedly younger in age than whether it can be extended into the early or middle Middle the first two that include deposits of different ages. or uppermost Middle Jurassic because, contrary to the Likewise, Mesolygaeius laiyangensis Ping remains with a known early or middle Middle Jurassic entomofaunas in semi-aquatic bug that was discovered respectively in the China and Russia, the insect assemblage in the Karabastau Laiyang Formation of Shandong, Lushangshufen Formation possesses distinct differences in the collective (=Lushangfen) Formation of western Beijing, Yixian characteristics. Many special groups have been merely Formation of Liaoning and Shahai Formation of Inner discovered in the latter, such as Prodiplatidae referable to Mongolia, China. It is clearly incorrect that the Yixian and Archidermaptera within Dermaptera, Protoscelinae Shahai Formations are coeval because there is another referable to Chrysomelidae within Coleoptera. intercalary stratigraphic unit, the Jiufutang Formation, Kalligrammatidae within Neuroptera, Mesoraphidiidae between them, and thus the latter must be younger in age within Raphidioptera, Nemestrinidae within Diptera, than the former. The aquatic beetle, Coptoclava longipoda Praeaulacinae referable to Praeaulacidae, and Sphecidae Ping, co-existed in the Dabeigou and Dalazi Formations in within Hymenoptera. These familial or subfamilial groups Hebei and Jilin Provinces, China. But the former is much are hardly existent in the undoubted early and middle older in age than the latter, and cannot be correlated. This Middle Jurassic entomofaunas; and accidentally, very few author deems that there were many aquatic and of the forerunners that belong to one or two of the semi-aquatic insects in the Mesozoic belonging to the above-mentioned groups occurred. Nevertheless, they longish-lived species, and they cannot serve as the proofs usually bloomed in the Late Jurassic-Early Cretaceous that the strata bearing these insects are contemporary. The Jehol Biota, such as Kalligrammatidae, Mesoraphidiidae, evolution velocity of insects is faster than other Nemestrinidae and Sphicidae. Therefore, a invertebrate and botanic groups, therefore, it seems to be biostratigraphic correlation and insect phylogenesis and also unreliable to determine the age and make evolution suggest that the Karabastau Formation was stratigraphic correlation based merely on very few groups deposited later than the early and middle Middle Jurassic or one and two known genera and species. But, there are but earlier than latest Late Jurassicearliest Early exceptions to most vertebrate groups because they usually Cretaceous @re-'Iithonian to Beniasian), viz., during the belong to the short-lived animal. This is the reason why early or middle Late Jurassic (Oxfordian or some researchers (e.g. Jiang et al., 2000) disagree with the Kimmeridgian). There is still an open question whether or deduction proposed by Swisher et al. (1999) that the fauna not the rocks were deposited in the Callovian. This of the lower Yixian Formation is at least 20 Ma younger