Bull. Kitakyushu Mus. Nat. Hist., 19: 25-42, pis. 1-4. March 31, 2000 Parafusulina (Permian Fusulinacea) from Hazegatoge, Kitakyushu City, Fukuoka Prefecture,Japan Yasuhiro Ota Kitakyushu Museum and Institute of Natural History, Nishihon-machi 3, Yahatahigashi-ku, Kitakyushu 805-0061, JAPAN (Received November 25, 1999) Abstract Well-preserved Permian fusulinacean species are present in conglomerates within the Dobaru Formation, the stratigraphically lowest part of the Early Cretaceous Wakino Subgroup. Three species of Parafusulina (Permian Fusulinacea), Parafusulina cf. kaerimizensis (Ozawa), Parafusulina sp. A, and Parafusulina sp. B, are described and illustrated. These fusulinaceans in clasts of non-crystalline limestone reworked into Early Cretaceous conglomerates indicate that the limestone source was close to the sedimentary basin of the Dobaru Formation. Introduction Fusulinacean localities are scarce in Kitakyushu City, Fukuoka Prefecture, Japan, and seldom yield well-preserved specimens, even though the Yobuno Group (M. Ota el al., 1992), one of the Carboniferous to Permian groups in the Akiyoshi Terrane, crops out widely there. Most limestones in the Yobuno Group generally are crystalline, as are other limestones of the Hirao Limestone Plateau, and sparsely contain fossils. Fusulinaceans were first reported by Yabe (1920) from limestone within the Otsumi Units (Nakae, 1997), and this was later confirmed by Fujimoto el al. (1961). The Early Cretaceous Wakino Subgroup also crops out widely in Kitakyushu City. This subgroup represents the lower part of the Kanmon Group and is divided into four formations, based on the biostratigraphic study of M. Ota and Yabumoto (1998). These formations are the Dobaru, Takatsuo, Gamo and Kumagai Formations, in ascending order. Diverse Cretaceous non-marine fossils have been reported from these formations by Nagao, (1929), M. Ota el al. (1979), and Yabumoto (1994). M. Ota and Yabumoto (1998) observed that fusulinacean species in conglomerates of the Mesozoic Dobaru and Takatsuo Formations had been derived from the Paleozoic Yobuno Group. Fujimoto (1935) and Sotsuka (1975) also reported fusulinacean specimens in conglomerates along the Murasaki River, but they were poorly preserved. The present study deals with the systematic paleontology of three species of Parafusulina collected from Hazegatoge, in the Kokuraminami Ward (Kokura- minami-ku) of Kitakyushu City in Fukuoka Prefecture. 26 Yasuhiro Ota Repository: All specimens used in this study are housed in the Kitakyushu Museum and Institute of Natural History, with the prefix of KMNH IvP for cataloged specimens. Sample numbers are shown in brackets. Acknowledgment: I wish to express my grateful thanks to Dr. Masamichi Ota, Counselor, Kitakyushu Museum and Institute of Natural History, who kindly read the manuscript and provided many suggestions during this study. I also wish to express my grateful thanks to Dr. Kimiyoshi Sada, Professor Emeritus, Hiroshima University, who kindly read the manuscript and offered many helpful suggestions throughout this study. I am especially grateful to the late Dr. Juichi Yanagida, Professor Emeritus, Kyushu University, who passed away quietly in his sick-bed on September 26, 1999. He gave me many suggestions for my study. Geology and paleontology All specimens for this study were collected from a locality at Hazegatoge, Kokuraminami Ward (Kokura-minami-ku), Kitakyushu City, Fukuoka Prefecture (Fig. 1). The Dobaru Formation, the stratigraphically lowest part of the Early «_~-.;. W^-^-AV.m^.^^S^..^ . MWM-i-ifXA C.^fSA//"#"^ KITAKYUSHU CITY Kokuraminami Ward i^S^^S^i\\\\KSSP§S^C<3# Fig. 1. Location map of study area (HZ001:Sample location). The base map is from 1/25,000 ofTokuriki published by Geographical Survey Institute in Japan. Parafusulina (Permian Fusulinacea) from Hazegatoge, Kitakyushu City, Japan 27 Cretaceous Wakino Subgroup, crops out near the fossil locality in Kitakyushu City and has an unconformable relationship with the underlying Paleozoic Yobuno Group (M. Ota and Yabumoto, 1998). Conglomerates and sandstone beds are exposed at the fossil locality, and they trend northeast and dip northward. The conglomerates can be traced northeastward and range in thickness from 3 to 10 meters. The generally poorly sorted conglomerates are made up of sub-angular to slightly rounded pebbles and cobbles of limestone, chert, and silt- to sand-sized gravel in a coarse sandstone matrix. Most of the limestone clasts consist of crystal line limestone that seldom contains fossils. When they occur, the fossils are poorly preserved, which makes species identifications difficult. The Parafusulina specimens discussed here were obtained from a limestone cobble (sample number: HZOOlOOJ-series) in the Dobaru Formation conglomerate in Hazegatoge, Kitakyushu City. The limestone cobble itself is slightly siliceous and fusulinid biosprite. Based on stratigraphic and paleontological evidence, this cobble was derived from the underlying Yobuno Group. The following three species ofParafusulina were found in the limestone cobble: Parafusulina cf. kaerimizensis (Ozawa), Parafusulina sp. A, and Parafusulina sp. B. Fragments of Pseudodoliolina sp. were also observed in two thin sections (sample numbers: HZOOlOOJ-0010-1 and HZ00100J-00T2-1). Unfortunately, the detailed wall structure of Parafusulina is not visible in most of the specimens due to poor preservation, but the keriotheca are seen in some sagittal sections. Specimens referred to Parafusulina cf. kaerimizensis (Ozawa) differ from Parafusulina kaerimizensis, which was discussed in detail by Toriyama (1958), by their small size. Parafusulina sp. A is characterized by a proloculus that is bigger than in Parafusulina kaerimizensis, but smaller than in Parafusulina ? edoensis (Ozawa). Parafusulina sp. B differs from the others by having a smaller and more slender shell. Judging from the affinity of these Parafusulina species, and the presence of Pseudodoliolina sp., the reworked limestone clast with these taxa is inferred to have originated from the Parafusulina kaerimizensis Zone (Toriyama, 1954a, b, 1958, M. Ota, 1977, Ozawa and Kobayashi, 1990, Ueno, 1991) in the Akiyoshi Limestone Group of Yamaguchi Prefecture, Southwest Japan, or from correlative strata of Middle Permian age. In addition, it should be noted that non-crystalline limestone with well-preserved taxa such as Parafusulina waspresent near the sedimentary basin of the Dobaru Formation in Early Cretaceous time. Systematic Paleontology Superfamily FUSULINACEA von Moller, 1878 Family FUSULINIDAE von Moller, 1878 Subfamily SCHWAGERININAE Dunbar and Henbest, 1930 Genus Parafusulina Dunbar and Skinner, 1931 28 Yasuhiro Ota Type-species: Parafusulina wordensis Dunbar and Skinner, 1931. American four. Sci., Ser. 5, 22, p. 261-263, pi. 2, figs. 1-4 [The specimen illustrated by Dunbar and Skinner (1937) as figure 5 on plate 72 was later designated as the holotype of Parafusulina wordensis Dunbar and Skinner by Thompson (1948)]. Generic diagnosis: Parafusulina has a medium to large, fusiform to subcylindrical shell, with slightly rounded poles. The coiling axis is straight to irregular, and mature shells are up to about 65 mm in length and consist of seven to nine volu tions. The proloculus is relatively large and the shell expands gradually. The spirotheca is rather thin relative to the size of the shell and is composed ofa tectum and keriotheca. The septa are strongly and regularly fluted. The strong flutings produce the numerous closed chamberlets, reaching to the top of the chambers, and the councils are observable. Chomata are absent or rudimentary in the inner volutions, but dense secondary deposits fill the chamber. The tunnel is low. Remarks: Parafusulina resembles Pseudofusulina Dunbar and Skinner (1931), but differs from it in having a rather thin wall, more strongly and regularly fluted septa, heavy axial fillings, well-developed cuniculi, and no phrenothecae. The Parafusulina species is very similar to species in the subgenus Skinnerella, which are characterized by small but rather thickly fusiform shells, with cuniculi at an early stage of development and present in the outer volutions. However, typical Parafusulina species evidently have more-dense secondary deposits throughout the shell, while Skinnerella species have deposits restricted in the inner volutions. The subgenus Eoparafusulina can be discriminated from Parafusulina by having a small and elongate shell, the presence of chomata, and weakly developed axial fillings. Monodiexodina proposed by Sosnina (1956) differs from Parafusulina by having a more elongate, subcylindrical to cylindrical shell. Bensh (1996) recently placed the subfamily Parafusulininae in Polydiexodinidae in a reference book on the classification of Paleozoic foraminifers reviewed by Ross (1999), and included Parafusulina in Parafusulininae. Parafusulina cf. kaerimizensis (Ozawa, 1925) Compare: 1925. Schellioicnia kaerimizensis Ozawa. four. Coll. Sci., Imp. Univ. Tokyo, 45, Art. 6, p. 31, 32, pi. 4, figs. 6, 7, pi. 6, fig. 5 [non pi. 4, fig. 5]. 1936. ?Pseudofusulina kaerimizensis, Fujimoto. Sci. Repls. Tokyo Bunrika Daigaku, Sec. C, (2), p. 65- 67, pi. 7, figs. 6-8, pi. 8, figs. 1-4. 1943. Parafusulina kaerimizensis, Minato and Nagao. four. Geol. Soc. fapan, 50(601), p. 310, figs. 1,2. 1955. Parafusulina kaerimizensis, Morikawa. Sci. Rep. Saitama Univ., Ser. B, 2(1), p. 107, 108, pi. 15, figs. 11-13. 1957. Parafusulina kaerimizensis, Kobayashi. Sci. Rep. Tokyo Kyoiku Daigaku,