SIMPLIFIED NASAL REGION. “The internal morphology of the nasal region is so profoundly different between monkeys and strepsirrhine primates that Cave (1973) opined that the latter be removed from the order Primates. Thus, along the entire anterior to posterior axis, the anthropoid nasal cavity is simplified by virtue of reduced turbinal projections.”
http://onlinelibrary.wiley.com/doi/10.1002/ar.23035/full