Multiple calcareous worm-like boring casts occur on the inner surface of the calcitic external layer of the bivalve Leptodesma sp. from the Kaugatuma Formation (lower Přídolí, Upper Silurian) of Saaremaa Island, Estonia. Most of the boring casts are oriented with their apertures towards the posterior margin of Leptodesma sp. The worm-like casts were originally borings in the aragonitic layer of the valve. The borings were filled with sediment and the aragonitic layer of the bivalve later dissolved. The orientation of the borings indicates that they were likely made during the life of Leptodesma. The boring worms likely used the feeding currents of the bivalve to capture suspended nutrients, so they may have been kleptoparasites. Based on the morphology of borings in Leptodesma, they likely housed some type of filter-feeding polychaete annelid.

在双壳类Leptodesma sp的钙质外层的内表面上出现了多个钙质蠕虫状的无聊铸件。来自爱沙尼亚萨列马岛的Kaugatuma组（上志留纪下部Přídolí下部）。大多数无聊的铸件的孔朝向Leptodesma sp。的后缘。蠕虫状的铸件最初是在阀门的合金层钻孔。钻孔中充满了沉积物，后来双壳类的石蜡层溶解了。钻孔的方向表明它们很可能是在Leptodesma的生命中制造的。无聊的蠕虫很可能利用双壳类动物的进食电流来捕获悬浮的营养物，因此它们可能是偷来的寄生虫。根据鱼鳞瘤中无聊的形态，他们可能收容了某种类型的滤食性多毛小食蚁兽。