FIGURE 12 in Feeding in marine mammals: An integration of evolution and ecology through time

FIGURE 12. Hypothesized ecological replacement of desmostylians (circles) by sirenians (squares) in the North Pacific Ocean. On the top, map of the localities of Tortonian age (11 Ma) where desmostylian and sirenian were recorded. On the bottom, map of the localities of Zanclean age (5 Ma) where sirenians were recorded. Desmostylia disappear from the fossil record by the end of the Tortonian (7.2 Ma) when sirenians, particularly Hydrodamalis spp., start colonizing this region, likely feeding on the same resources. Only one occurrence per genus is reported in each locality. Locality data for each occurrence of Desmostylia and Sirenia in the Tortonian and Zanclean were downloaded from PBDB (https://paleobiodb.org) using the search parameters described in Materials and Methods and then plotted on the map.