A New Triassic Ammonite from Yanaizu, North of Inai near Ishinomaki, Miyagi Prefecture

Proceedings of the Japan Academy Pub Date : 1949-01-01 DOI:10.2183/pjab1945.25.11_32

H. Yabe

{"title":"A New Triassic Ammonite from Yanaizu, North of Inai near Ishinomaki, Miyagi Prefecture","authors":"H. Yabe","doi":"10.2183/pjab1945.25.11_32","DOIUrl":null,"url":null,"abstract":"Several months ago,. Mr. F. Ueda, teacher of the Toyoma High School, Miyagi Prefecture, showed the writer a peculiar ammonite from a Triassic sandy argyllite exposed at Yanaizu, 12 km south of Toyoma and 20 km north of Inai near Isinomaki. This ammonite attracted the writer's attention on account of the unusual growthform of its last whorl, which is first produced linearly and then incurved again as in the Jurassic Macroscaphites and the Cretaceous Scaphites, while it resembles, in its coiled part, Danubites japonicus Shimizu 1> from the Anisic Hollandites beds of Inai. The annexed figure shows this specimen in natural size. All specimens of the Anisic ammonites from the Hollandites beds of Inai are moulds, the shell-substance being never preserved. The moulds are always one-sided ; that is to say, there is no specimen ever seen by the writer, with both surfaces preserved. Moreover, the majority of the specimens are obliterated in a definite manner, lengthened in one direction and correspondingly shortened in the other, due to lateral presure. The present specimen from Yanaizu is in the same mode of preservation. The Yanaizu specimen consists of a coiled part and an uncoiled, key-shaped part; the dimensions of the coiled part are :","PeriodicalId":85351,"journal":{"name":"Proceedings of the Japan Academy","volume":"1 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"1949-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Japan Academy","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2183/pjab1945.25.11_32","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

Several months ago,. Mr. F. Ueda, teacher of the Toyoma High School, Miyagi Prefecture, showed the writer a peculiar ammonite from a Triassic sandy argyllite exposed at Yanaizu, 12 km south of Toyoma and 20 km north of Inai near Isinomaki. This ammonite attracted the writer's attention on account of the unusual growthform of its last whorl, which is first produced linearly and then incurved again as in the Jurassic Macroscaphites and the Cretaceous Scaphites, while it resembles, in its coiled part, Danubites japonicus Shimizu 1> from the Anisic Hollandites beds of Inai. The annexed figure shows this specimen in natural size. All specimens of the Anisic ammonites from the Hollandites beds of Inai are moulds, the shell-substance being never preserved. The moulds are always one-sided ; that is to say, there is no specimen ever seen by the writer, with both surfaces preserved. Moreover, the majority of the specimens are obliterated in a definite manner, lengthened in one direction and correspondingly shortened in the other, due to lateral presure. The present specimen from Yanaizu is in the same mode of preservation. The Yanaizu specimen consists of a coiled part and an uncoiled, key-shaped part; the dimensions of the coiled part are :

查看原文本刊更多论文

宫城县石卷附近稻奈北部柳井津的新三叠纪菊石

几个月前，……上田先生是宫城县富马高中的老师，他向笔者展示了一种特殊的菊石，它来自于富马以南12公里、伊奈以北20公里、石卷附近的柳井，这是一种三叠纪砂质硬砂岩。这种菊石引起作者的注意，是因为它的最后一个螺轮的生长形式很不寻常，它首先是线性的，然后又像侏罗纪的大纹石和白垩纪的大纹石那样弯曲，而它的卷曲部分又象伊奈岛的Anisic Hollandites床上的Danubites japonicus Shimizu 1>。附图显示了该标本的自然尺寸。所有来自伊奈岛荷兰岩床的茴香菊石标本都是霉菌，这种壳状物质从未被保存下来。模具总是片面的;也就是说，作者从未见过两面都保存完好的标本。此外，由于侧向压力的作用，大多数标本都以一定的方式被湮没，在一个方向上延长，在另一个方向上相应地缩短。现在柳井津的标本也采用了同样的保存方式。Yanaizu试样由一个盘绕部分和一个未盘绕的键形部分组成;卷绕件的尺寸为:

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Proceedings of the Japan Academy

自引率

0.00%

发文量