Final answer:
Haplorhine primates, unlike strepsirhine primates, do not have a grooming claw on the second toe. Instead, they have nails on all of their digits.
Step-by-step explanation:
Haplorhine primates, unlike strepsirhine primates, have a number of anatomical features that distinguish them. One of the key features is the absence of a grooming claw on the second toe. Strepsirhines have a claw-like nail on the second toe, while haplorhines do not. Instead, haplorhines have nails on all of their digits, similar to humans.