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In mammals, the quadrate and articular bones have moved into the middle ear (Figure 29.37). The malleus is derived from the articular bone, whereas the incus originated from the quadrate bone. This arrangement of jaw and ear bones aids in distinguishing fossil mammals from fossils of other synapsids. Figure 29.37 Mammalian ear bones.
16 de mai. de 2023 · Characteristics of Mammals. Mammary glands: Mammals possess specialized mammary glands that produce milk to feed their young offspring. Hair or fur: Most of them have hair or fur covering their bodies, providing insulation, protection, and sensory functions. Direct birth: They give direct birth to live young, with well-developed offspring.
Evolution of Mammals. Mammals are synapsids, meaning they have a single, ancestrally fused, postorbital opening in the skull. They are the only living synapsids, as earlier forms became extinct by the Jurassic period. The early non-mammalian synapsids can be divided into two groups, the pelycosaurs and the therapsids.
mammal, Any member of the class (Mammalia) of warm-blooded vertebrate s having four limbs (except for some aquatic species) and distinguished from other chordate classes by the female’s milk-secreting glands and the presence of hair at some stage of development. Other unique characteristics include a jaw hinged directly to the skull, hearing ...
Mammal. A mammal (from Latin mamma 'breast') [1] is a vertebrate animal of the class Mammalia ( / məˈmeɪli.ə / ). Mammals are characterized by the presence of milk -producing mammary glands for feeding their young, a neocortex region of the brain, fur or hair, and three middle ear bones.
Mammals, comprising about 5,200 species, are vertebrates that possess hair and mammary glands. Several other characteristics are distinctive to mammals, including certain features of the jaw, skeleton, integument, and internal anatomy. Modern mammals belong to three clades: monotremes, marsupials, and eutherians (or placental mammals).
Characteristics of Mammals. The presence of hair is one of the most obvious signs of a mammal. Although it is not very extensive on certain species, such as whales, hair has many important functions for mammals. Mammals are endothermic, and hair provides insulation to retain heat generated by metabolic work.
