New ichnospecies and redescription of Caedichnus Stafford et al., 2015, traces indicative of durophagous predation

Abstract

Predation traces on marine shelled prey are informative and widely utilized indicators of predatory attacks in the scientific literature. Most of these traces remain undescribed and unnamed, making it difficult to identify and quantify predatory behaviour in the fossil record. Two new ichnospecies, Caedichnus cisus and Caedichnus lunaris, have been described and erected into the emended ichnogenus Caedichnus, assigned to the ichnofamily Belichnidae (Wisshak et al., 2019), and a previously proposed synonymy of Caedichnus with Bicrescomanducator is rejected. Both new ichnospecies are indicative of an attack from a durophagous predator and are often associated with repair scars, indicating the attack was unsuccessful, allowing the prey to repair its shell to some degree. The morphology of the prey shell and the method of predator attack are likely to influence both the shape of the resulting trace and whether one results in subsequent repair. Describing predation traces will create consistency between researchers and facilitate the comparison of predation types, predators, and shell morphologies.