The P(1) elements of the conodonts Zieglerodina paucidentata Murphy & Matti, 1982, and Zieglerodina petrea Huskova & Slavik, 2020, share similar gap in their denticulation, a characteristic easily recognizable among rather morphologically similar spathognathodontids from near the Silurian-Devonian boundary. The ambiguity in the diagnosis of Z. paucidentata (an earliest Lochkovian species) may affect precision in the recognition of the boundary.
New geographic occurrences of Z. petrea in the Cellon section from the Carnic Alps, and Z. cf. paucidentata from the Atrous section in Morocco is reported. The revised data have shown that some specimens previously described as Z. paucidentata or Z. cf. paucidentata probably belong to other taxa; and therefore, their applicability for correlation of the Silurian-Devonian boundary is limited.