A claim about a whole and a claim about one of its parts need not concern the same predication. The text illustrates this with a dark body and the color of its teeth.
Compare:
“Most of the animal’s body is black.”
“The animal's teeth are not black.”
These relate to the whole and one part. Both can be true because the predominant color of the body does not entail that the teeth share it. The question would change if the first statement explicitly included every part.
To judge contradiction accurately, identify which exact part or whole receives the predicate.