{"title":"In-place operculum demonstrates that the Middle Cambrian Protowenella is a hyolith and not a mollusc","authors":"J. S. Peel","doi":"10.1080/03115518.2021.2004225","DOIUrl":null,"url":null,"abstract":"Abstract Protowenella is an early–middle Cambrian, isostrophically coiled, calcareous microfossil originally described from the middle Cambrian (Miaolingian) of Australia; it has been referred previously to the molluscan classes Monoplacophora, Helcionelloida or Gastropoda. A unique specimen from the Henson Gletscher Formation (Miaolingian Series, Wuliuan Stage) of North Greenland has a bilaterally symmetrical operculum preserved in place within the shell aperture. Paired cardinal processes and clavicles on the inner side of the operculum indicate that Protowenella was a hyolith morphologically close to the orthothecid Conotheca. Protowenella is transferred from Mollusca to Hyolitha, Order Orthothecida, Family Protowenellidae nov., representing a novel morphological departure from the generally slender cones of other hyoliths. John S. Peel [ john.peel@pal.uu.se ], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-75236, Uppsala, Sweden.","PeriodicalId":272731,"journal":{"name":"Alcheringa: An Australasian Journal of Palaeontology","volume":"69 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"7","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Alcheringa: An Australasian Journal of Palaeontology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/03115518.2021.2004225","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 7
Abstract
Abstract Protowenella is an early–middle Cambrian, isostrophically coiled, calcareous microfossil originally described from the middle Cambrian (Miaolingian) of Australia; it has been referred previously to the molluscan classes Monoplacophora, Helcionelloida or Gastropoda. A unique specimen from the Henson Gletscher Formation (Miaolingian Series, Wuliuan Stage) of North Greenland has a bilaterally symmetrical operculum preserved in place within the shell aperture. Paired cardinal processes and clavicles on the inner side of the operculum indicate that Protowenella was a hyolith morphologically close to the orthothecid Conotheca. Protowenella is transferred from Mollusca to Hyolitha, Order Orthothecida, Family Protowenellidae nov., representing a novel morphological departure from the generally slender cones of other hyoliths. John S. Peel [ john.peel@pal.uu.se ], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-75236, Uppsala, Sweden.
Protowenella是一种早中寒武纪、等向盘绕的钙质微化石,最初描述于澳大利亚中寒武纪苗岭期;它以前被称为软体动物纲单placophora, Helcionelloida或腹足类。北格陵兰岛五流期苗岭系Henson Gletscher组的一个独特标本在壳孔内保留了一个两侧对称的盖层。包盖内侧成对的基突和锁骨表明原温氏菌在形态上是一种接近于正鞘壳的水蛭。原温氏菌从软体动物转移到原温氏菌科原温氏菌科原温氏菌目水螅虫,代表了一种与其他水螅虫通常细长的球体不同的形态。瑞典乌普萨拉大学地球科学系(古生物学系),Villavägen 16, SE-75236, John S. Peel [john.peel@pal.uu.se]。