Abnormal trilobites from the Silurian and Devonian of Europe

Malformed trilobites have been documented in deposits ranging from the Cambrian to the Permian. Continued examination of novel malformed specimens provides insight into how trilobites recovered from injuries, experienced genetic abnormalities, and adapted to pathological conditions. This study focuses on trilobites from the Silurian and Devonian of Europe, presenting new records of: (i) a moulting-related injury in Lioharpes venulosus; (ii) genetic malformations in Calymene blumenbachii and Treveropyge sp.; and (iii) a moulting injury or genetic anomaly in Scutellum (Scutellum) pardalios. Additionally, we record evidence of bryozoan growth on a C. blumenbachii specimen. Our findings provide important data for contextualizing the paleobiology of early and middle Paleozoic trilobites, especially related to responses to ecological pressures.