Primates are a kind of animal. Primates are from the kingdom Animalia. The phylum of primates is Chordata. The class of primates is Mammalia. Which means they are one type of mammal.
Primates developed around 85 million to 55 million years ago. They evolved from small terrestrial mammals. They have a relatively larger brain as compared to other mammals. Primates are one of the most social animals who like to live in groups.Â
There are specific characteristics of primates that distinguish them from other types of mammals. Around 60% of primate species are currently endangered by extinction.
Origin of Primates
As discussed earlier, primates developed about 85 million to 55 million years ago. They originate from small terrestrial mammals. The characteristics of primates’ adaptation to the changing environment around them. The mammals who adapted well developed into primates. Humans are also primates. Primates include around 200 species of different mammals.Â
If scientists were to list four characteristics of easily identifiable primates, these characteristics would be visual acuity, large brains, colour vision, and a great degree of freedom in shoulder joint movements. New species of primates keep getting discovered. Over 25 new species were found in the 2000s. Three new species have been found in the 2020s.
Classification of Primates
They are primarily divided into two types: Prosimian and Anthropoidea.
- Prosimian-
 The characteristics of primates of this kind are more ancestral or primitive than that of other types of primates. The animals like lorises, lemurs, etc., belong to this type.
- Anthropoidea-
The structure of Anthropoidea types of primates is quite conservative. They consist primarily of apes and monkeys. Anthropoidea primates are also called Simians. Anthropoid means bearing similarity to human beings.
However, it was found that these two types are closely related; hence, the classification had to be revised.
Now the two subtypes of primates are-
 Strepsirrhini and Haplorhine.
- Strepsirrhini-Â
This subtype of primates includes lorises and lemurs. They have a reflective layer on their eye, which gives them night vision. They have wet noses. These are the defining characteristics of primates of the Strepsirrhini type.Â
This is important to know because it will assist you in answering UPSC questions about primate anthropology traits.
- Haplorhine –
Haplorhine primates are also called primates with dry noses. They can exhibit a wide range of facial expressions. Most of them have single births; however, some species like tamarins and marmosets can also give birth to twins and triplets.
Characteristics of Primates
The primates exhibit many distinguishable characteristics that set them apart from other mammals. Learning about them is essential for answering characteristics of primates’ UPSC anthropology questions.
- Large brains- The brains of primates are comparatively more significant about their body size.
- Primates tend to depend more on their visual senses instead of their olfactory senses, that is, the sense of smell.Â
- The majority of primate species have sexual dimorphism. This suggests that sexes of the same species have variances in non-reproductive traits.
- Opposable thumbs- One of the reasons why primates are considered to be developed, and superior species is because of their opposable thumbs. It helps them to handle and manipulate objects to a much greater extent.
- Primates are pretty social animals. They like moving and living in a group or a family.Â
- Most primate species are arboreal, with some exceptions, like humans. Arboreal means the ability to climb and live in the trees.
- Separate fingers and toes- Animals, with a few exceptions, have five fingers and five tools on their hand and feet, respectively. The ability to rotate their thumbs makes primates dexterous. Dexterity helps them perform delicate actions.
- Most mammals are diurnal. They are active during the day and take rest during the night.
- Mammals usually have long gestation periods. It is a period taken by a foetus to reach full development after conception.
- Grooming- Highly developed primates like engaging in a pleasurable activity called grooming. They clean themselves well and make sure their appearance stays attractive.
Evolution of Primates
The primates are said to have emerged around the Cretaceous-Paleogene boundary. Primates are monophyletic. The anthropoid primates may have crossed the Atlantic Ocean through Africa to South America. The Olds monkeys most probably vanished from Europe around 1.8 Mya. In the Miocene period, monkeys and apes started spreading to Asia and Europe from Africa.
 The study of fossils and molecular studies estimate that modern humans first originated in Africa about 1 to 2 Lakh years ago.Â
Hybrids of primates are formed in captivity. Hybrids may be created due to environmental pressure or when humans keep animals together in zoos.
Conclusion:
Primates belong to Kingdom Animalia and the phylum Chordata. They are the more developed type of mammals. Primates originated about 85 million to 55 million years ago. Since then, primates have been categorised into many subspecies.
The primates exhibit specific characteristics that distinguish them from less developed mammals. They include arboreal adaptation, big brains, heightened sense of vision, opposable thumbs, more flexibility in shoulder movements.
The most commonly found species of primates are monkeys, apes, Gorillas. Humans are also primates. Primates are divided into subtypes Strepsirrhini and Haplorhine. The present form of humans developed about 1-2 Lakh years ago.