ABSTRACT

A new genus and species of encrusting tentaculitoid, Lindstroemiella eichwaldi, from the Silurian (Ludfordian Stage, Ludlow) of Saaremaa Island in Estonia, is described. This tentaculitoid shares common structural features (inwardly directed pseudopunctae and vesicles) with Anticalyptraea, but differs from the latter in having a spirally coiled, microconchid-like shell with a variously oriented aperture, thin and sharp transverse ridges and lacking an inverted cone-like morphology. Unlike other tentaculitoids (microconchids, trypanoporids, cornulitids), these encrusters, unique with respect to morphology and shell structure, have so far not been taxonomically classified at the ordinal level. Now, taking into account that such tentaculitoids are taxonomically and morphologically more diverse than previously assumed, we propose to include them in a separate order Anticalyptraeida. Unlike microconchids and cornulitids, anticalyptraeids are the least studied group of tentaculitoids and thus poorly recognized. In part, this may be due to their misidentification with associated spirally coiled microconchids, to which anticalyptraeids are very similar at juvenile stages.

http://www.zoobank.org/lsid:zoobank.org:act:C1E9D9A4-555E-4F5A-BEDC-8046CCA58BD9

摘要

描述了爱沙尼亚 Saaremaa 岛志留纪（Ludfordian Stage，Ludlow）的一种新属和新种的结壳触须类动物Lindstroemiella eichwaldi 。这种触须类与Anticalyptraea具有共同的结构特征（向内定向的假点和囊泡），但与后者的不同之处在于具有螺旋盘绕的微型贝壳状外壳，具有不同方向的孔径，薄而尖锐的横向脊并且缺乏倒锥形的形态。与其他触须类动物（微型贝类、锥虫类、角孢类）不同，这些外壳在形态和壳结构方面是独一无二的，迄今为止尚未在序数水平上进行分类。现在，考虑到这种触须类在分类学和形态学上比以前假设的更加多样化，我们建议将它们包括在一个单独的顺序 Anticalyptraeida 中。与微贝类和角螺类不同，antilyptraeids 是研究最少的类触角类动物，因此识别率很低。在某种程度上，这可能是由于它们与相关的螺旋卷曲的小贝类的错误识别，

http://www.zoobank.org/lsid:zoobank.org:act:C1E9D9A4-555E-4F5A-BEDC-8046CCA58BD9