Data from: Convergence on dental simplification in the evolution of whales

The fossil record of mammal dentition provides crucial insight into key
ecological and functional transitions throughout their evolutionary
history. For cetaceans, both extant clades differ markedly from their stem
ancestors; neither retains the differentiated dentition, nor the
tribosphenic molars characteristic of Mammalia. We used quantitative
measures of dental complexity across fossil and living cetaceans to
identify a trend towards dental simplicity through the Neogene. Both
extant cetacean clades depart from the ancestral mammalian condition and
concurrently converge upon a reduced and simplified dentition; modern
mysticetes all have become entirely edentulous (at birth) and living
odontocetes possess teeth as single rooted, conical pegs. These two
parallel trends accompany major shifts in feeding strategy (i.e.,
filter-feeding in mysticetes, and echolocation in odontocetes), suggesting
that these evolutionary innovations for prey acquisition are enabling
factors for the loss of prey processing and subsequent convergence on
dental simplification.