The Journal of the Geological Society of Japan
Online ISSN : 1349-9963
Print ISSN : 0016-7630
ISSN-L : 0016-7630
Volume 44, Issue 524
Displaying 1-10 of 10 articles from this issue
  • [in Japanese]
    1937 Volume 44 Issue 524 Pages 341-353
    Published: 1937
    Released on J-STAGE: April 11, 2008
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  • [in Japanese]
    1937 Volume 44 Issue 524 Pages 354-367
    Published: 1937
    Released on J-STAGE: April 11, 2008
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  • Yasuo Sasa
    1937 Volume 44 Issue 524 Pages 368-375
    Published: 1937
    Released on J-STAGE: April 11, 2008
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    § In this paper is treated a right lower third molar (M-3) of the so-called Mammoth Elephas primigenius (BLUMENBACH)., The state of preservation of the present specimen, though slightly waterworn, is rather good, and deeply worned by grinding nearly to the root of the ridges at the posterior part., § In the crown view, the outer side of the tooth is nearly straight and the other slightly convex., The gringing surface is oval and represents rather deep concavity., The length of the crown is 206 mm., while that of the grinding surface is 202mm., The maximum width of the crown (also that of the grinding surface) is 73mm., at the eleventh ridge., The greatest height of the crown is 192mm., at the hindermost ridge and that of the crest is about 60mm., at the fourteenth ridge., It consists of sixteen ridges excluding the anterior and posterior talons., The frequency of ridges in the length of 100mm., is about 10 in the grinding surface., All the ridges are distinctly exposed, with light brown coloured dentines, creamy white coloured enamels and chocolate brown cements., The ridges are weakly flexuous, the anterior and the posterior side of them being nearly parallel; they are almost straight in the anterior part of the crown, while it is convex anteriorly in the posterior part., The interspaces between the ridges are each nearly 5mm., in width and the breadth of the ridge itself is about 7-8mm., The enamel layer of the ridge is rather thin, about 1., 2mm., thick in the external and internal marginal parts of the ridge, showing no constrictions and having slight coarse plications., § The present specimen is said to have been found by a fisherman on the beach in th Nokoro village on the coast of Taraika Bay of Japanese Saghalin., Therefore, its geological mode of occurrence is regretably uncertain, but considering all the circumstances, it was derived most probably from the raised coastal plain deposits, the Rukutama Series of upper Diluvial age., This series, ten meters in thickness with the overlying so-called "Tundra" bed and the underlying upper Pliocene Nokoro bed, togerher builts up the sea cliffs of about twenty ot fifty meters high and is composed of loose sand, mud and gravel, intercalating thin layers of clay and peat., § The occurrence of the present molar is remarkable from palaeogeographical point of view, as no remains of a Mammoth were hitherto known from the northern Japanese Islands; shortly, it suggests us the presence of a state of land connection between Saghalin Island and the Asiatic continent at some date of the Diluvium, as the occurrence of the Mammoth fossil is well known from the Siberian and Manchurian Diluvial deposits.,
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  • Tomoye Urita
    1937 Volume 44 Issue 524 Pages 376-382
    Published: 1937
    Released on J-STAGE: April 11, 2008
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    In July and September, 1934, two fossil mammoth teeth were found out at the northern part of the Aniwa Bay in Saghalien, by Mr., Y., Suzuki and Mr., T., Kaga respectively; both of them are now kept in the Odomari Middle School., According to Prof., Hikoshichiro MATSUMOTO's determination, they belong to the following two species., 1., Parelephas armeniacus (FALCONER); left M-3 This was dredged out in September, 1934, from the bottom of the sea, 7-8 fathoms deep, off Funamicho, Odomari., This specimen, which is strongly worn, consists of 21 ridges in the present condition, and measures 290 mm in length as preserved, 77 mm in the maximum width at the eleventh ridge, 113 mm in the greatest height of the crown at the seventeenth ridge., In a lateral view, the ridges in the posterior half are slightly curved and the breadth of the ridge is narrower than the valley between them., The frequency of the ridge in a length of 100 mm is 7-8 on the inner side, 8-10 on the outer side, and 9-10 on the grinding surface., The grinding surface is elogatedly elliptical, more or less curved as a whole and almost even longitudinally., the disks of the ridges are so greatly elongated that the brims of them, i., e., the layers of enamel which measure 2., 6 mm in thickness, look almost parallel with each other., 2., Mammonteus primigenius (BLUMERBACH); left M-3 In July, 1934, this specimen was dredged out lying 17 or 18 fathoms deep off Fukamimura, Odomari Ditrict., It is strongly worn and consists of 21 redges in the present condition., Its length as preserved is 265 mm, its maximum width 78 mm at the tenth ridge, and its greatest height of the crown is 91 mm at the fifteenth ridge on the outer side., The ridges in the posterior half are slightly curved and the breadth of the ridges are wider than the valleys lying between them., The frequency of the ridges in a length of 100 mm is 8-9 on the inner side, 10-12 on the outer side, and 10-12 on the grinding surface., The grinding surface is elongatedly elliptical and slight ly concave longitudinally, so as to sink some 9 mm at the ninth ridges., The disks of the ridges are very similar to those of the specimen of the preceding species.,
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  • [in Japanese]
    1937 Volume 44 Issue 524 Pages 383-391
    Published: 1937
    Released on J-STAGE: April 11, 2008
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  • [in Japanese]
    1937 Volume 44 Issue 524 Pages 392-396
    Published: 1937
    Released on J-STAGE: April 11, 2008
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  • Tokio Shikama
    1937 Volume 44 Issue 524 Pages 405-420
    Published: 1937
    Released on J-STAGE: April 11, 2008
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    The occurrence of a rich mammalian fauna in some of the limestone fissures and caves of Kuzuu in Aso-gun, Totigi-ken, came to the first time in 1930 to the notice o f geologists ; since that time, the author repeated excavations of the ossuaries to the last year, with kind assistance of Mr., O., TANAKA, a resident in Kuzhu, to whom he is much obliged for facilitating the dangerous and difficult task of excavation and fossil collection., The laboratory work of fossils collected is still in progress under the guidance of Prof., H., YABE in the Institute of Geology and Palaeontology, Tohoku Imperial University, Sendai, where all the materials obtained by excavation are deposited., The fissure deposits of Kuzuu, the "Kuzuu formation " of the author, is divisible into three parts, lower, middle and upper., The lower Kuzuu formation consists of two fossil beds, the lower, Sus bed and the upper, Stegodon bed; the upper Kuzuu has seven, Geoclemys-, amphibia-, Palaeoloxodon-, Parastegodon-, Microtus-Mels-, carnivora- and Moschus beds in ascending order; and the middle Kuzuu is barrcn of fossils., In the present article only the Geoclemys-, amphbia-, Microtus-Meles-, carnivora- and Moschus beds of the upper Kuzuu are taken into consideration., The fossil bones, teeth, antlers and shells procured by the author from Kuzuu during the past six years amount to 4033 in number; they comprise 36 species of mammalia, 5 species of aves, 3 species of reptilia and 3 species of amphibia (anura), altogether representing more than 424 (or more) individuals in total., The actual number of samples and the estimated number of individuals (in parenthesis) of each species are given in Table 1; from this table one can get the general, though faint, idea of the numerical ratio of skeletal parts excavated of each species to the approximate individual numbers by estimation., In Table 2 are given only the estimated numbers of individuals of each species in order to show the relative population among the different species; perhaps this statistical method may serve for palaeoecological analyses of the fossils beds or consideration of the mechanism of the fossil entombment., In strict sense, of course, it is almost impossible to estimate the total number of specimens preserved in one ossuary, especially by intermittent excavaations in small scale as in the author's enterprise; yet his intention lies in knowing, if possible, the proportion in numerical value, though only in approximation, of the skeletal parts of differnt animals procured frpm each ossuary., The specific elements of the fossil fauna under consideration are diveded into the following three categories according to their frequency or population., 1., Dominant elements, in which the finds of the skeletal parts correspond to 20 individuals or more, and are found in all or at least in the majority of different ossuaries., 2., Subordinate elements of A type in which the finds of the skeletal parts correspond to less than 20 and more than 5 individuals and are found at least in the majority of the different ossuaries., 3., Subordinate elements of B rype in which the finds of the skeletal parts correspond to less than 5 individuals and are fonud in only a limited number of the ossuaries., The dominant elements and subordinate ones of A type are listed in Table 3; most of them are fossorial in habit, and their skeletal parts are rather completely recovered., On the contrary, the subordinate elements of B type are known only of very few and fragmental remains., The Kuzuu ossiferous fissures, so far as the 5 fossil beds are concernd, are more or less like the Conard fissures in Arkansas, United State of America, in the constitution of fauna., In the case of Kuzuu, it can be at present said that the total number of the skeletal parts procured in each ossuary is less that twelve times the estimated number of animal individuals. [the rest omitted]
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  • Teiichi Kobayashi
    1937 Volume 44 Issue 524 Pages 421-437
    Published: 1937
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
  • Koiti Suzuki
    1937 Volume 44 Issue 524 Pages 438-443
    Published: 1937
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
  • Shigeyasu Tokunaga, Fuyuji Takai
    1937 Volume 44 Issue 524 Pages 444-446
    Published: 1937
    Released on J-STAGE: April 11, 2008
    JOURNAL FREE ACCESS
    The Specimen, a fragment of the right horizontal ramus of the mandible containing the first, second, and thrid molars, was dredged from the sea bottom off the Island of Kotuti, Kagawa Prefecture in January 1933., It is now preserved at Waseda University, Tokyo., The mandible is broken at tha anterior margin of the first molar, the ascending ramus and the inner and lower sides of the horizontal ramus being also damaged., Palaeopathologically speaking, a number of intresting features are observed in this specimen., First, a compound odontoma of the first and second molars has taken place, which is a benign tumor derived from an abnormal arrangenment of dentine, enamel, and cementum and a sporadic calcification in tooth development., Second, a great hypertrophy of the right ramus has happened, which has given rise to a bulbous appearance to the jaw., Third, the concavity of the diseased molar is greater than that of a normal molar., Fourth, the breadth of the former is one-and-a-half times that of the normal., And fifth, the enamel figure on the friction surface of the anomalous molar is irregular as shown in the plate., The third molar, which now contains the anterior talon and twelve ridges, has lost 4-8 ridges and the posterior talon., Its grinding had not yet begun The maximum length of its crown is 180 mm., and its width at the sixth ridge 60 mm., The height of the crown is 128 mm., at the fifthe ridge, and 132 mm., at the tenth., The frequency of ridges in a standard length of 100mm is 6., 5., For reasons given above it is almost impossible to determine its specific name, but the writers believe that it may belong to Palaeloxodon namadicus (FALCONER and CAUTLEY), the well known Pleistocene elephant., Finally the writers wish to express their thanks to Professor Tosikazu Tokoro Nippon Dental College, for dental information received.,
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