Santichnus Verde, Castillo, Martín-González et Cruzado-Caballero, 2022

Diagnosis: Bioerosion structure that develops on the surface of hard calcareous substrates as a canal semicircular in cross-section that follows a logarithmic spiral path up to three whorls, in which the width of the canal varies gradually following the logarithmic spiral proportions.

Remarks: Santichnus can be easily distinguished from Spirolites Uchman et al. (2018), another anchoring spiral trace fossil produced by vermetid gastropods. Santichnus has a distinguishable discrete canal along its spiral path and lacks the perpendicular annulations in contrast to Spirolites Uchman.