Strepsirhini is a term used in primatology and physical anthropology to refer to a parvorder of primates that includes lemurs, lorises, and galagos (bushbabies). This group is characterized by several features, including a wet nose, a grooming claw on the second digit of the hind foot, and a toothcomb - a set of lower incisors and canines specialized for grooming.

The term Strepsirhini comes from the Greek words "streptos" meaning twisted and "rhinos" meaning nose, referring to the wet, rhinarium (naked, moist snout) found in these primates. This is one of the two major divisions within the infraorder Lemuriformes, the other being Haplorhini, which includes tarsiers, monkeys, apes, and humans.

Haplorhini is a term used in the field of primatology and physical anthropology to refer to a parvorder of simian primates, which includes humans, apes (both great and small), and Old World monkeys. The name "Haplorhini" comes from the Greek words "haploos," meaning single or simple, and "rhinos," meaning nose.

The defining characteristic of Haplorhini is the presence of a simple, dry nose, as opposed to the wet, fleshy noses found in other primates, such as New World monkeys and strepsirrhines (which include lemurs and lorises). The nostrils of haplorhines are located close together at the tip of the snout, and they lack the rhinarium or "wet nose" that is present in other primates.

Haplorhini is further divided into two infraorders: Simiiformes (which includes apes and Old World monkeys) and Tarsioidea (which includes tarsiers). These groups are distinguished by various anatomical and behavioral differences, such as the presence or absence of a tail, the structure of the hand and foot, and the degree of sociality.

Overall, Haplorhini is a group of primates that share a number of distinctive features related to their sensory systems, locomotion, and social behavior. Understanding the evolutionary history and diversity of this group is an important area of research in anthropology, biology, and psychology.