Final answer:
The development of the mammalian brain requires several key features like a folded cerebral cortex and a corpus callosum, but meninges, although present, are not required for its development.
Step-by-step explanation:
The development of a mammalian brain requires various structures and features that differentiate it from the brains of other vertebrates, but not all these features are essential for its development. For instance, the development of the mammalian brain does not require meninges, although they are present and provide protective coverings for the brain. Key features in the evolution and development of the mammalian brain include a highly convoluted and folded cerebral cortex, a divided optic lobe, and the presence of the corpus callosum in eutherian mammals, which is essential for integrating functions between the cerebral hemispheres.