A unique case of healed injury in a Cambrian trilobite

The middle Cambrian Jince Formation of the Příbram–Jince Basin is globally renowned as a classical repository of well-preserved skeletal marine fauna, including abundant remains of trilobites. An exceptionally preserved articulated exoskeleton of middle Cambrian trilobite Conocoryphe sulzeri (Schlotheim, 1823) exhibits a prominent palaeopathological anomaly interpreted here as a healed traumatic injury. We suggest to attribute the extensive damage of the right side of the cephalon and three anterior-most right thoracic pleurae to a failed predatory attack. The anomalocaridid genus Hurdia and the large bivalved arthropod Tuzoia represent two potential candidates for durophagous predators responsible for the described trilobite injury. The large size of healed injury demonstrates a high level of exoskeletal regeneration in trilobites.