New cornulitid from the Ohesaare Formation (late Přidoli) of Saaremaa, Estonia

A new cornulitid species Cornulites baranovi sp. nov. is described from the Ohesaare Formation (late Přidoli) of Saaremaa, Estonia. The new species exhibits straight to slightly curved tubes that expand moderately in diameter, a vesicular tube structure and strong annular crests and costae. In addition to C. baranovi sp. nov., Conchicolites sp. also occurs in the Ohesaare Formation. The diversity of cornulitids is low in the Přidoli of Estonia, but not lower than in the Silurian of Estonia in general. C. baranovi often forms a symbiotic association with the bryozoan Fistulipora . It is not sure whether sealing off one cornulitid specimen by host bryozoan was a result of space competition or a post- mortem overgrowth. Specimens of C. baranovi also occur as solitary encrusters and aggregative encrusters in the Ohesaare Formation. C. baranovi presumably represents ecological generalists among the Silurian tentaculitoid tubeworms.