Assertion: cetacean | /r/HasAspect | lower jaw
Facets:
Source sentences:
text: Like all other mammals but unlike all fish, cetaceans nurse their young with milk produced by the mother, are endothermic (warm-blooded), breathe air, have a lower jaw that consists of a single bony element (the dentary), and have three small bones (hammer, anvil, and stirrup) subserving sound transmission within the ear.