The mineralization of dinosaur soft tissue in the lower Cretaceous of Las Hoyas, Spain

The mineralized soft tissue of a dinosaur, only the second discovery of its kind, is reported from the Low er Cretaceous of Las Koyas, Spain. Cellular details of mineralized skin and muscle of Pelecanimimus are replicated in an iron carbonate. The outline of this ornithomimosaur is preserved by a phosphatized microbial mat that enshrouded the carcass. It confirms the existence of either a throat pouch or dewlap, and soft occipital crest. This study confirms the importance of microbial mats in the fossilization of soft tissues and emphasises the need for careful monitoring of vertebrate remains for mineralized soft tissues prior to acid preparation.