Analysing Trophic Competition in †Otodus megalodon and Carcharodon carcharias through 2D-SEM Dental Microwear

Abstract

The extinction of the massive apex predator ^†Otodus megalodon during the Pliocene is a subject of debate, with climate change and emergence of competitors as potential factors, such as Carcharodon carcharias. We explore trophic interactions of ^†O. megalodon and the C. carcharias by the analysis of dental microwear. For this purpose, high-resolution casts were made from ten megalodon teeth and six white shark teeth. Then, replicas were produced for examination using a Scanning Electron Microscope. Following a previous work on non-occlusal teeth of bony fishes, density and scratch length as well as mean vector were taken into account for the analysis. Our findings revealed that ^†O. megalodon shows a slight preference for less abrasive diets compared to C. carcharias. However, no significant differences were found in the dental microwear patterns of both species. These results provide additional evidence of a similar trophic spectrum between C. carchariasand ^†O. megalodon in the Mediterranean Sea basin, contrasting with previous data obtained through texture analysis. However, due to the inability to estimate sizes, we cannot rule out possible ontogenetic dietary differences. Therefore, future studies estimating sizes and incorporating data from other basins could provide more information.