To work out whether ancient whales were predators or filter feeders, the scientists created 3D models of the teeth of the eight extinct whale species.
They also created 3D tooth models of four land-dwelling carnivores — the coyote, the lion, the dingo and the puma — and five seals (some of which filter-feed with their teeth).
"We wondered which teeth are the fossil whale teeth more like: the seals that filter feed, or the carnivores that live on land and definitely use their teeth to cut up food?" Dr Evans said.
They found that two species of seal — leopard and crabeater — were clearly distinct from the rest of the group analysed. Those species had blunt, rounded teeth that fit in with their known use of filter-feeding, Dr Evans said.
But the whale teeth were far closer to terrestrial carnivores like the lion than they were to those seals.