3.3. Anatomical extent
The dental crown was the anatomical region where dental wear was observed most frequently, with wear down to the cingulum or root level being less frequent or even insignificant (Fig. 5). Wear restricted to the crown was common (80% or less) in Fraser's dolphin Lagenodelphis hosei, Guiana dolphin S. guianensis and striped dolphin S. coeruleoalba. The latter two species had coronal wear in more than 70% of the sample. Conversely, in killer whales (O. orca) and false killer whales (P. crassidens) a relatively high percentage of teeth were worn down to the cingulum level. Teeth worn down to the root level were registered in relatively high frequencies (over 40%) in two species with distinct body and tooth size, the false killer whale P. crassidens and the much smaller Clymene dolphin, S. clymene.