The principal aim of the present study has been to consider the moment of production of the different skeletal anomalies (borings, embeddings and pathologies) for obtaining an accurate datation of the affected microstructures. The use of this textural criterion has usually been accepted in those research studies interested in the moment of production of the texture, such as, carbonate petrology and genesis of submarine cements. The material studied in this report comes from the collections of solitary rugose corals without dissepiments, from Upper Viséan of Northwestern Ossa-Morena region (Los Santos de Maimona and Guadiato Basin) except some specimens supplied by Prof. J. Kullmann from the Emsian of Bostanci at Istanbul (Turkey) which are totally recrystallized and previously drilled as well. This study is based on the occurrence of three kinds of evidences: Borings: Boring action penetrates and dislodges coral structures, providing a source for dating, since boring action must be posterior to these structures. Its study is based on the analysis and the interpretation of morphology of borings, and also it is completed with the description of their borders, and the different alteration processes wich occur in this areas. Embeddings and pathologies: Both anomalies are contemporary with the biocrystallization, generating borders with concordant microelements. Description of complete diagenetic alterations in drilled specimens and comparison with the described borders. The possibility of describing rugose corals perforated and totally recrystallized (i.e. with a previous well known microstructure) constitutes finally an excellent reference for comparing the realized observation in the other paragraphs.