Final answer:
Controversy refers to disagreement among scientists regarding the classification of the fossil Toumai as either a hominid or an ape.
Step-by-step explanation:
In this context, controversy means disagreement or dispute among scientists regarding the classification of the fossil Toumai. Some scientists believe that Toumai is the oldest known hominid or primitive human ancestor, while others argue that it is an ape. The disagreement stems from differences in the interpretation of the fossil's characteristics and how it fits with other scientific evidence.