Mammals PDF

What is mammal? is a class of animals which have hair or fur, they are warm blooded animals (warm blooded: animals that can regulate and maintain constant internal body temperature ● can adapt to an extreme environment ● the secretion of milk by females for the nourishment of the young through a ma...

What is mammal? is a class of animals which have hair or fur, they are warm blooded animals (warm blooded: animals that can regulate and maintain constant internal body temperature ● can adapt to an extreme environment ● the secretion of milk by females for the nourishment of the young through a mammary gland) ● A. ORIGIN OF MAMMALS ● The first mammals appeared about 230 million years ago, during the triassic period ● Fossils indicate that they evolved from a now- extinct order of reptiles called therapsids ● Therapsids were very abundant during the late Permian period (210-240 million years ago). ● Fossil remains of them , such as tooth and jaw fragments, show a mixture of reptile and mammalian characteristics. ● After the dinosaurs become extinct about 65 million years ago, this opened up many new habitats and resources to mammals, and mammals took over many of the ecological roles previously filled by dinosaurs. ● Mammals inhabit a wide range of habitats on land and on water. They can survive in some of the coldest and hottest environments on earth. ● Adaptation such as blubber, large lungs , external ears , specialized teeth, and a large stomach containing symbiotic microorganism that can break down cellulose in plants are just some of the many adaptations that have enabled mammals to inhabits such diverse environments. -mammalian heart has four chambers -Mammals have hair/fur -warm blooded animals CHARACTERISTICS OF MAMMALS -project external ears Breathe through lungs -usually have tails and four limbs -every mammal is a vertebrate -sweat glands -feed by milk ANIMALS HABITAT Habitat-a natural home or environment of an animal or plants TYPES OF MAMMALS 1. MONOTREME MAMMALS 2. MARSUPIAL MAMMALS 3. PLACENTAL MAMMALS CHARACTERISTICS OF MONOTREME MAMMALS ● ● ● two features monotremes share with other mammals are hair and milk production. they do not have nipples and young monotremes do not nurse(young oozes milk from glands located from the mothers belly) platypus inhabits lakes and streams (its broad, flat tail and webbed from feet make it an excellent swimmer) ● lay eggs ● refers to a primitive mammals ● do not have placenta ● have a pouch to carry eggs ● do not have teeth ● do not have external ears MONOTREME MAMMALS The babies feed on mothers milk similar to any other mammals(from the belly pores) 04 -this type of mammals lay eggs and the offspring come out from the hatched eggs 01 03 -the ancient forms of mammals 02 -monotremes mammals belong to subclass prototheria MONOTREME MAMMALS 04 PLATYPUS 01 EXAMPLES OF MONOTREM E MAMMALS 02 03 ECHIDNA MONOTREME MAMMALS ECHIDNA STEROPODON PLATYPUS CHARACTERISTICS OF MARSUPIAL MAMMALS ● ● ● ● ● presence of pouch for females give birth to very small live young babies are blind at birth and have no ears or back legs lactation period is longer than that of the other placental mammals fenestrated palate-large gaps in roof of mouth ● ● ● found in north and south america, but primarily in Australasia TEETH . number of incisors in upper jaw different from the number in the lower jaw : in the placental the number is equal brain is smaller and more simple MARSUPIAL MAMMALS 04 -This type of mammals give birth to barely formed offspring from there, babies drink mothers milk to get all the nutrients and become a fully evolved baby 01 03 -the baby grows on a pouch on the mothers belly Most common marsupial -kangaroo, koala ,numbat 02 MARSUPIAL MAMMALS 04 KANGAROO 01 EXAMPLES OF MARSUPIAL MAMMALS 03 KOALA 02 OPOSSUM NUMBAT MARSUPIAL MAMMALS BANDICOOT KANGAROO DUNNART KOALA GLIDERS OPOSSUM CHARACTERISTICS OF PLACENTAL MAMMALS ● ● ● ● carry unborn young in the uterus until young can survive. oxygen and nutrients are transferred from mothers blood to baby's blood. the placenta is a membrane providing nutrients and waste and gas exchange between mother and the developing young. mammals are diverse group living in land and in water some can fly. ● ● ● an organ called the placenta allows the diffusion of nutrients and oxygen from the mothers blood, across placental membranes and into the blood of developing fetus. waste materials from the fetus diffuses in the opposite direction and are eliminated by the mothers excretory system. differs greatly in size. PLACENTAL MAMMALS -This type of mammals constitutes a more significant chunk of mammals in animal kingdom -offspring grow into a well-formed structure inside the mothers belly for a long time called placenta -the baby in the womb gets the nourishment from the mothers diet via the umbilical cord 04 01 03 Placental mammals belong to subclass eutheria 02 PLACENTAL MAMMALS 04 ELEPHANT 01 EXAMPLES OF PLACENTAL MAMMALS 03 CAT 02 DOG HUMAN QUOLLS WALLABY NUMBAT TASMANIAN DEVIL WOMBAT CLASSIFICATION OF MAMMALS ACCORDING TO FOOD CONSUMPTION CARNIVORE ● is an organism that eats mostly meat, or the flesh of animals. ● Sometimes carnivores are called predators. ● Examples: HERBIVORE ● are animals that only plants ● they eat leaves, shoots and twigs. ● Examples: OMNIVORE ● is an animal that eats both plants and animals for their main food. ● also hunt prey and other times; they forage for plant matter like herbivores. ● are also scavengers, which means they eat dead decaying matter. ● Examples: