Query: Extinct animals of North America including Oligocene mammals
Domain: animals
Relevant documents:
Eomysticetus
Kalobatippus
Agorophius
Salishicetus
Morawanocetus
Proscalops
Ekgmowechashala
Hyaenodon
Maiabalaena
Sitsqwayk
Kentriodon
Leptictis
Squalodon
Aetiocetus
Fucaia
Simocetus
Ankylorhiza
Chonecetus