Trilobites of the genus Toxochasmops from the Ordovician of Estonia

A study of the genus Toxochasmops from northern Estonia revealed that it is more diverse both at the generic and specific levels than was known previously. The earliest species of Toxochasmops from the upper Viru Series were assigned to the new subgenus T. (Schmidtops). Apart from the type species Phacops (Chasmops) maxima Schmidt, 1881, this subgenus comprises the new species T. (S.) proavus and T. (S.) vironiensis. The subgenus T. (Toxochasmops) includes Chasmops inge Rõõmusoks, 1953, P. (C.) wesenbergensis Schmidt, 1881, as well as the new species T. (T.) estonicus, T. (T.) notabilis, and T. (T.) vormsiensis. The earliest representative of this subgenus is T. (T.) granuliferus sp. nov. from the uppermost Keila Stage of the Viru Series (lower Dicranograptus clingani Zone).