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On the Damesellian Province O F the Early Upper Cambrian Age on The No. 3] Proc. Japan Acad., 63, Ser. B (1987) 63 17. On the Damesellian Province of the Early Upper Cambrian Age on the West Pocific Side By Teiichi KOBAYASHI, M. J. A. (Communicated March 12, 1987) The Damesellian province is defined by the Damesellidae discussed in the preceding article. Although the family flourished most in China, it is known to be distributed in the Sayan-Altai Mountains in the North (Ivshin, 1960; Pokrovskaya, 1961), in Australia (Opik,1967), Iran (Kushan, 1971), Afghanistan (Wolfart, 1974) and Karatau, Central Asia (Ergaliev, 1980). Therefore the areal variation of the damesellid assemblages in such an extensive region on the West Pacific side and their time-relation are two important subjects which are taken up in this article. In 1976 Opik reported the occurrences of the Damesellidae in Queensland, Australia where it is represented by ten genera, namely Damesella, Blackwelderia, Dipyrgotes*, Cyrtoproras, Meringaspis*, Stephanocare, Dipentaspis*, (?) Teinis- tion, Histiomona* and Paleodotens* among which six genera marked asterisks are new. P'alaeodotes is referred to the Drepanurinae, but the remainder is all located in the Damesellinae inclusive of the Dorypygellinae. Dipentaspis accom- panied by a damesellid, gen. et sp. inlet. appears first in the late Middle Cambrian. Dipentaspis and Damesella are found in the passage zone to the early Upper Cambrian Mindyallan stage. Three trilobite zones are distinguished in this stage. Meringaspis occurs in the lower and middle zones, Stephanocare and Palaeodotes in the middle zone, and Blackwelderia in the middle and upper zones. The remaining genera are restricted to the upper zone, i.e. Glyptagnostus stolidotus zone. No damesellid is known from the superjacent Idamean stage. Kushan (1973) described Drepanura (Spinopanura) erbeni gen. et sp. nov. from the Arborz Mountains in North Iran. There Wittke (1984) distinguished the Drepanura-Torif er-Eokaolishania assemblage zone below and the Pro- chuangia-Paracoosia assemblage zone above in the Upper Cambrian of Mila Kuh. The former must be Kushanian and the latter Paishanian in age. In Central Afghanistan Wolfart (1974) reported Blackwelderia and Arias pis, gen. nov. from the Surkh Bum area. Incidentally, not only Ariaspis but Dipentaspis also occur in China. Ac- cording to Zhou Tian-mei and other Chinese palaeontologists (1983) Paleodotus Opik, 1967 and Drepanura (Spinopanurus) Kushan, 1973 are two junior synonyma of Bergeronites (Sun), Kuo, 1965, and Bergeronites dissidens (Opik) is found in the early Upper Cambrian in Hunan (1977). It is noted further that Dipleuropyge Lermontova, 1951 placed in the Damesellidae (Osnoby, 1960), is represented by the pygidium fairly distinct from other damesellids in the entire posterior margin between a pair of unusually stout lateral spines and obsolete segmen- tation of the axial and pleural lobes. In Northern Asia typical Kushanian genera are reported as follows : Drepanura, Blackwelderia and Koptura are accompanied by Paradoxidian 64 T. KOBAYASHI [Vol. 63(B), and Olenidian agnostids in the early Upper Cambrian (or Dresbachian) of the northern Siberian platform (Demokidov and Switski, 1959). Damesella occurs in the Agnostus pisiformis bearing Kujandinsky horizon of Salair in the Sayan-Altai folded zone (Ivshin, 1960). Blackwelderia is found in the pisiformis zone and Drepanura in the super- jacent Glyptagnostus f ossus zone in the northeastern Siberian platform (Pokrov- skaya, 1961). Blackwelderia and Drepanura are contained in the Glyptagnostus stolidotus zone of Yaktusk district in the eastern Siberian platform (Yaktusk Conference Report, 1963). Recently Ergaliev (1980) found an important succession of damesellids in Maloga Karatau. The leading species in five zones are in descending order as follows : Glyptagnostus stolidotus zone ... Prodamesella quadrata Kormagnostus simplex zone ... Palaeodotes scutisulcatus and Meringaspis karatauensis Lejopyge laevigata zone ... Blackwelderia scutisulcatus Lejopyge armata zone ... Prodamesella convexa, Meringaspis karatauensis Goniagnostus nathorsti zone ... Prodamesella convexa Because the agnostids are well developed, it is a Para-Kushan sequence. Since I have called attention to the global distribution of Glyptagnostus (1949), Opik (1961, 1967) distinguished Glyptagnostus stolidotus zone below the G. reticulatus zone in Queensland. Likewisely the Glyptagnostus f ossus (i.e. G. stolidotus) zone containing Crepicephalus and Drepanura was found below the G. reticulatus zone in Siberia (Pokrovskaya, 1961; Yaktsuk Conf. Rep. 1963). As the result of an extensive study on Glyptagnostus and associated trilobites in North America Palmer (1962) determined the succession of the following species and subspecies of Glyptagnostus as below. Glyptagnostus reticulatus reticulatus =Aphelaspis zone Glyptagnostus reticulatus angelini =Crepicephalus zone Glyptagnostus stolidotus zone =Cedaria zone In Sweden Glyptagnostus reticulatus and its subspecies nodulosus occur in the basal part of the Olenus zone (2a-b and 2b-c respectively) and Drepanura eremita was found in the Agnostus pisiformis zone (1). On the Hunan-Kweichou border, however, Drepanura sp. was found by Jegorova and others (1953) together with Glyptagnostus f ossus (i.e. G. stolidotus) and G. reticulatus at one locality (loc. 416) and at another (loc. 413) with Pro- ceratopyge con fzrons which is a member of the Lejopyge laevigata zone (C3). Judging from the above statements it is found that Prodamesella, Merin- gaspis and Blackwelderia appear successively from the nathorsti zone to the armata zone through the laevigata zone in Karatau. In Queensland Dipentaspis occurs first in the late Middle Cambrian Steamboat sandstone in the Lejopyge laevigata zone and then Damesella in the passage beds to the Mindyallan stage. Palaeodotes appears in the Cyclagnostus quasiversa zone in the middle part of the stage. In Karatau Meringaspis as well as Palaeodotes are contained in the Kormagnostus simplex zone and Prodamesella in the stolidotus zone. Therefore these two zones may be nearly contemporaneous with the Mindyallan stage. Prodamesella is, however, a pre-Kushanian genus in China. The increase of the generic number of damesellids from the laevigata zone No. 3] Damesellian Province, West Pacific Side 65 (1 genus) toward the stolidotus zone (7 genera) through the quasivesta zone (3 genera) in Queensland is a remarkable evolution of this trilobite family, but it died out in Queensland and Karatau with the stolidotus zone. Because this zone lies just below the reticulatus zone, it must be the correlative of the Agnostus pisi f ormis zone containing Drepanura eremita. As to the life range of the Damesellidae the fossil locality 416 on the Hunan-Kweichou border bears a sole question, because Glyptagnostus reticulatus, G. f ossus and Drepanura sp. were collected therefrom. Whether or not, they were collected from the exactly same horizon. At any rate the Damesellidae was flourished in the early Upper Cambrian age so well that it constituted such a distinct faunal province on the west Pacific side extending as far as Central Asia, but the family completely annihilated at the end of the Kushanian age. Ref erences'' Chu Chao-Zing (1959) : Trilobites from the Kushan formation of north and northeastern China. Mem. Inst. Geol., Inst. Pal. Acad. Sinica, no. 2, pp. 81-128, 6 pls. Ergaliev, G. X. (1980) : Middle and Upper Cambrian trilobites of Magogl Karatau. 211 pp. (20 pls.). Jago, J. B. (1974) : Glyptagnostus reticulatus from the Huskisson River, Tasmania. Pap. Proc. Roy. Soc. Tasmania, 1'07, 117-126, 1 pl. Jegorova, L. I, et al. (1963) : Trilobite faunas of Kueichou and Western Hunan. Bull. Geol. Inst., Geol. Surv. China, Sect. B, 3(1), 117 pp. (14 pls.). Kobayashi, T. (1935) : The Cambro-Ordovician formations and fossils of South Chosen (Korea), Part 3, Cambrian faunas of south Chosen with a special study on the Cambrian trilobite genera and families. J. Fac. Soc. Imp. Univ. Tokyo, Sec. 2, 4(2), 49-344, 24 pls. (1941) : Occurrence of the Kushan trilobites in northern Anhui and a note on the Rakuroan complex of the Shankiangan Basin. J. Geol. Soc. Japan, 48, 403-409. (1941-42) : Studies on Cambrian trilobite genera and families, 1-4. Japan. J. Geol. Geogr., 19, 25-40, pls. 1-2, 41-51, pl. 3, 59-70, pls. 5-6, 197-212, pls. 20-21. -- (1942) : Some new trilobites in the Kushan Stage in Shantung . J. Geol. Soc. Tokyo, 49, 41-45. (1944) : On the Cambrian formations in Yunnan and Haut-Tonkin and the trilo- bites contained. Japan. J. Geol. Geogr., 1'9, 107-138. -- (1949) : The Glyptagnostus Hemera, the oldest world-instant . ibid., 21,1-6, pl. 1. (1960) : Supplement to the Cambrian faunas of the Tsuibon Zone with notes on some trilobite genera and families. J. Fac. Sci. Univ. Tokyo, Sec. 2, 12 (2), 329-420, pls. 19-21. -- (1966) : The Chosen group of south Korea . ibid., 16(1), 1-84. --- (1966) : The Chosen group of north Korea and south Manchuria . ibid., 16(2), 381-534. -- (1967) : The Cambrian of eastern Asia and other parts of the Continent . ibid., 16(3), 381-534. (1971) : The Cambro-Ordovician faunal provinces and the interprovincial corre- lation. ibid., 18(1), 129-299. Kushan, B. (1973) : Stratigraphie and Trilobitenfauna in der Mila-Formation (Mittel- kambrium-Tremadoc) im Alborz-Gebiege (N-Iran). Palaeontogr. Bd. 144, Abt. A, LFG. 4-6, 113-165, 26-34 pls. Li Shan-Ji (1978) : Trilobita, pp. 179-285. Palaeontological Atlas of Southwest China, Sichuan Fasc. (1), Sinian-Devonian, 615 pp., 185 pls. *' See
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