catarhines

Catarhines are a clade of placental mammals that includes the primates and their closest relatives. The term "catarhine" is derived from the Greek words "kata" meaning "down" and "rhine" meaning "nose," referring to the downward-facing nostrils of these animals. This clade is characterized by a number of shared anatomical features, such as a reduced number of upper premolars, a more complex social structure, and a larger brain relative to body size compared to other mammals.

The catarrhines are divided into two main groups: the cercopithecoids, which include the Old World monkeys and apes, and the hominoids, which include the great apes and humans. The cercopithecoids are further divided into the cercopithecines, which include the Old World monkeys, and the hominoids, which include the great apes and humans.

The catarrhines first appeared in the fossil record around 40 million years ago, during the Eocene epoch. They diversified rapidly during the Oligocene and Miocene epochs, with the hominoids emerging around 20 million years ago. The catarrhines are found in Africa, Asia, and Europe, with the great apes and humans being the only catarrhines found outside of Africa.

The catarrhines are an important group of mammals, as they include the primates, which are the most intelligent and complex of all mammals. They are also an important group for evolutionary studies, as they provide insights into the evolution of social behavior, tool use, and language.