Internal moulds of the relatively small− to moderate−size shells of Early Devonian ectocochleate cephalopods (typically<150 mm diameter) occasionally display traces of repaired shell damage. Presumably, these animals with their highlyspecialized buoyancy device, the phragmocone, lived in the water column. It is uncertain as to how the shells of these ani−mals were damaged; one likely cause would be predatory attacks but the identity of the perpetrator remains uncertain. Sofar, no remains of arthropods capable of breaking or cutting shells have been found in the fossiliferous outcrops of this agein the Anti−Atlas (Morocco). The only macrovertebrate remains of this age are of acanthodian and placoderm fish whichprobably lived a more or less benthonic life style. Additionally, a fish attack on these cephalopods would probably havedestroyed most of the thin−shelled conch and killed the animal. Most of the repaired shell breaks are triangular in shapewhich is characteristic for cephalopod bite marks. Additionally, the paired arrangement of the fractures in over 70bactritoids supports the hypothesis that it was a cephalopod attacking another cephalopod. It cannot be excluded with certainty that occasional vertebrate attacks left traces on their shells. Fossil evidence indicates that the development of tightlycoiled conchs was a rapid evolutionary event in the Ammonoidea in the Early Devonian; however, the evolution of coil−ing is probably not directly related to predation pressures because the ratio of injured to healthy specimens is roughly thesame in Zlíchovian bactritoids with orthoconic and ammonoids with coiled shells h