Early Ordovician molluscs with an exceptional preservation from the Timan-Pechora Basin of Russia

Unique preservation of the oldest colour pattern ( ≈ 490 Ma) of a molluscan shell and the first record of colour pattern in monoplacophorans are reported from a well that penetrated Early Ordovician strata in the Timan-Pechora Basin of Russia. The unusual preservation reflects low subsidence temperatures and minimal tectonic deformation. A colour pattern in the form of radial stripes coincides with the pattern of multiple muscle attachments to the shell, which obviously influenced the mantle margin responsible for the shell formation and pigment deposition. We assume that this type of colour pattern is one of the most ancient to have appeared in molluscan evolution. (c) 2014 Geologiska Foereningen