MAMMALS:
Mammalia is one of the 2 clades of living amniotes. They are synapsid.
Characteristics of Mammalia:
Fleshy external ears
Endothermic
Body mostly covered with hair
Sweat, scent and sebaceous glands
Skin underlain by a thick layer of fat
Skull with 2 occipital condyles. Lower jaw is a single enlarged bone (dentary).
Jaw joint between squamosal and dentary bones. Seven cervical vertebrae.
Fused pelvic bones
Mouth with diphyodont teeth. Teeth heterodont in most.
Brain highly developed, especially cerebral cortex. 12 pairs of cranial nerves
Olfactory sense highly developed
Middle ear with 3 bones
Separate sexes. Internal fertilisation. Copulatory organ. Sex determined by
chromosomes
Foetal membranes of amnion, chorion and allantois. Mostly viviparous, some oviparous. Young nourished by
milk from mammary glands
Excretory system of kidneys and ureters that open into a bladder. Urea main nitrogenous waste
Lungs with high surface area from alveoli and ventilated by aspiration. Larynx present. Secondary palate
separates air and food passages. Muscular diaphragm ventilates lungs. Convoluted turbinate bones in the nasal
cavity warm and moisten air
Heart with 2 atria and 2 ventricles. Separate pulmonary and systemic circuits. Nonnucleated biconcave RBCs
Mammalia is one of the 2 clades of living amniotes. They are synapsid.
Characteristics of Mammalia:
Fleshy external ears
Endothermic
Body mostly covered with hair
Sweat, scent and sebaceous glands
Skin underlain by a thick layer of fat
Skull with 2 occipital condyles. Lower jaw is a single enlarged bone (dentary).
Jaw joint between squamosal and dentary bones. Seven cervical vertebrae.
Fused pelvic bones
Mouth with diphyodont teeth. Teeth heterodont in most.
Brain highly developed, especially cerebral cortex. 12 pairs of cranial nerves
Olfactory sense highly developed
Middle ear with 3 bones
Separate sexes. Internal fertilisation. Copulatory organ. Sex determined by
chromosomes
Foetal membranes of amnion, chorion and allantois. Mostly viviparous, some oviparous. Young nourished by
milk from mammary glands
Excretory system of kidneys and ureters that open into a bladder. Urea main nitrogenous waste
Lungs with high surface area from alveoli and ventilated by aspiration. Larynx present. Secondary palate
separates air and food passages. Muscular diaphragm ventilates lungs. Convoluted turbinate bones in the nasal
cavity warm and moisten air
Heart with 2 atria and 2 ventricles. Separate pulmonary and systemic circuits. Nonnucleated biconcave RBCs
