Cornulites sp. and Fistulipora przhidolensis formed a symbiotic association in the Pridoli (latest Silurian) of Saaremaa Island, Estonia. This Cornulites sp.–F. przhidolensis association is the youngest example of cornulitid–bryozoan symbiosis. Symbiosis is indicated by intergrowth of both organisms. The cornulitids are completely embedded within the cystoporate bryozoan colony, leaving only their apertures free on the growth surface of bryozoan. In terms of food competition, this association could have been slightly harmful to F. przhidolensis as Cornulites sp. may have been a kleptoparasite. There may have been a small escalation in the evolution of the endobiotic life mode of cornulitids as the number of such associations increased from the Ordovician to Silurian. It is likely that Palaeozoic bryozoan symbiosis reached its maximum in the Late Ordovician. Most of the symbiotic bryozoans in the Palaeozoic are trepostomes, and the diversity of symbiotic associations was also greatest among trepostomes.

中文翻译：

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在爱沙尼亚萨列马岛的Pridoli中，倒角藻类苔藓孢子与角果蝇共生共生

Cornulites SP。和Fistulipora przhidolensis形成的Saaremaa岛，爱沙尼亚在Pridoli一个共生体（最新志留系）。此Cornulites sp.- F. przhidolensis关联是cornulitid-苔藓虫共生的最年轻的例子。共生由两种生物的共生指示。角质瘤完全包埋在cystoporate bryozoan菌落内，仅在bryozoan的生长表面上留有小孔。在食物的竞争而言，这种关联可能是轻微危害F. przhidolensis为Cornulitessp。可能是klepto寄生虫。随着这种关联的数量从奥陶纪到志留纪增加，角膜动物的内生生命模式的演变可能会小幅升级。古生代的苔藓虫共生可能在奥陶纪晚期达到最大。古生代中大多数共生的苔藓动物是海龟体，而在海龟体中，共生联系的多样性也最大。