They’re thinking too hard.
Ruminant mammals survived, non ruminant grazers were wiped out.
“Ruminant mammals survived, non ruminant grazers were wiped out.”
On the episode of Animal Planet’s “Prehistoric Park,” that dealt with sabre-toothed cats, they pointed out that these cats went extinct because their prey animals, the grazers, died out due to a changing climate.
George