characteristics of each sub class of mammals with examples?
Answers
Mammals
are a group of vertebrate animals that have the following characteristics (other animals DO NOT have these characteristics)
Mammals have
Mammary glands, capable of secreting milk, food from which all the offspring of mammals are supplied. This is its main characteristic, from which derive its name of mammals.
On his skin, keratinized structures called hairs. Some animals have it in abundance and others have it in very few quantities (even if it is in an embryonic state).
they have ear pavilions, except whales, dolphins and others that live in the water and that in their evolutionary process have lost them for hydrodynamic reasons.
three bones in the middle ear: hammer, anvil and stirrup, with the exception of monotremes,
a jaw formed only by the dental bone
The articulation of the jaw with the skull between the dentary and the squamosal.
Some examples:
sheep
ʙᴇ sᴍᴀʀᴛ........^_^
Answer:
sub classes
class: Mammalia
subclass: Prototheria Theria
infraclass: Metatheria Eutheria
Members of the subclass Prototheria click this icon to hear the preceding term pronounced lay eggs like most non-mammalian vertebrates. However, they feed their newborn with mammary gland secretions like all other mammals. They lack nipples, but the skin over their mammary glands exude milk for their babies. The Prototheria are also referred to as monotremes click this icon to hear the preceding term pronounced, which literally means that they have one opening for excretion and reproduction. This is similar to birds and reptiles. The Prototheria are also similar to reptiles in some aspects of their skeletons. Notably, their legs are on the sides of their bodies rather than underneath them. This results in a reptile-like gait. There are only three surviving rare species groups of Prototheria. These are the Australian platypus and 2 echidna (spiny anteater) species of Australia and New Guinea.
All other living mammalian species, including humans, are in the subclass Theria click this icon to hear the preceding term pronounced. They have in common the fact that they give birth to live young. Therian mammals apparently did not evolve from the Prototheria. The relatively primitive prototherian reproductive system evidently evolved after their evolutionary line separated from the other early mammals.
The oldest infraclass of therian mammals is the Metatheria click this icon to hear the preceding term pronounced, or the marsupials click this icon to hear the preceding term pronounced. Their young are born very immature and cannot live without further development in the mother's pouch. The word marsupial comes from marsupium, the Latin word for purse. Marsupials include kangaroos, koalas, opossums, and many other similar animals. Most of them are native only to Australia and New Guinea.
Most mammal species, including humans, are in the infraclass Eutheria click this icon to hear the preceding term pronounced. They are also referred to as placental click this icon to hear the preceding term pronounced mammals. Eutherian mothers carry their unborn children within the uterus where they are nourished and protected until an advanced stage is reached. This is made possible by the umbilical cord and placenta which connects the fetus to the uterus wall and enables nutrients and oxygen to get to the offspring as well as provides a means of eliminating its waste. At the same time, the placenta functions as a barrier to keep the blood cells and other components of the immune systems of the mother and her fetuses separate to prevent their destruction.
Giant pandas are an exception among the placental mammals. Their babies are born at only 1/4 the size predicted for the general placental mammal pattern. Marsupial babies are born at an even more immature stage because their rudimentary placentas are comparatively inefficient in nurturing fetuses.
Placental mammals have been extremely successful in out-competing monotremes and marsupials for ecological niches. This is mostly due to the fact that their babies are born more mature, which increases their chances of survival. This is particularly true of herbivores that are predated on by carnivores. Marsupials give birth to early stage fetuses. Placental mammals give birth after fetuses are much more developed. The downside is that pregnant placental mammals must consume significantly more calories to nurture their fetuses and themselves, especially during the second half of their pregnancies. Like monotremes and marsupials, placental mammals feed their babies with milk from their mammary glands. Species that have multiple births at the same time generally have more mammary glands. The number ranges from 2 in primates, goats, sheep, and horses to 18 in pigs.
Placental mammals are found on all continents, in the air, and in the seas. Primates, cats, dogs, bears, hoofed animals, rodents, bats, seals, dolphins, and whales are among the dominant placental mammal groups today. Nearly 94% of all mammal species now are placental mammals (5,080 species out of 5,416).
hope it is helpful.....