SQUALICORAX CHIPS A TOOTH: A CONSEQUENCE OF FEEDING-RELATED BEHAVIOR FROM THE WENONAH-MT. LAUREL AND NAVESINK FORMATIONS (LATE CRETACEOUS: CAMPANIAN-MAASTRICHTIAN) OF MONMOUTH COUNTY, NEW JERSEY

Chipped and broken teeth are common components in both modern and fossil sharks with serrated tooth morphology. Tooth damage occurs primarily as splintering, cracking, and flaking near the cusp apex where the enameloid has been removed and exposes the osteodentine and orthodentine. Analysis of large, modern shark jaws with serrated tooth morphology as well as literature sources indicate such damage is the result of enormous forces applied during feeding as the tooth apex impacts robust skeletal elements of prey items. Damage seen in an assemblage of isolated teeth from sharks Squalicorax pristodontus and Squalicorax kaupi from the late Cretaceous New Jersey bear striking resemblance to these modern shark teeth and suggests similar feeding behavior occurred. Rare North American preservation events with Squalicorax associated directly and indirectly with osteichthyan and reptile skeletal elements reinforce this viewpoint. Tumbling experiments with isolated modern and fossil teeth with serrated morphology further demonstrate that many chipped and broken Squalicorax teeth are feeding-related and not taphonomic in origin. Evolution of rapid tooth replacement in large sharks with serrated tooth morphology such as Squalicorax ensured maximum functionality after feeding-related tooth damage occurred. Serrated tooth morphology and rapid tooth replacement in large sharks throughout the Mesozoic and Cenozoic strengthened their place as apex predators in today’s oceans.