Sublethal punctures in body chambers of Mesozoic ammonites (forma aegra fenestra n. f.), a tool to interpret synecological relationships, particularly predator-prey interactions

The new forma aegrafenestra n. f. sensuHölder (1956) is introduced to describe healed injuries to the body Chambers of Jurassic/Cretaceous ammonites, primarily behind the peristome but normally excluding the peristome itself. The different outlines and positions of these window-like sublethal injuries indicate two different Subtypes of injury inflicted by two different types of predator. Some of the large-scale ventral injuries occurring since the Late Devonian were presumably due to attacks by durophagous vertebrates, whereas the smaller, more or less rounded and mainly lateral puncture marks in Liassic to Cretaceous ammonite Shells can be traced back to unsuccessful attacks by stomatopod crustaceans. Identification of the specific predators responsible for characteristic injuries will give information about synecological relationships and life-modes of the attacked ammonites.