This keynote may help you organise your research notes
Duck Billed Platypus Facts
Britannica School : MonotremeMonotreme, (order Monotremata), any member of the egg-laying mammalian order Monotremata, which includes the amphibious platypus (family Ornithorhynchidae) and the terrestrial echidnas (family Tachyglossidae) of continental Australia, the Australian island state of Tasmania, and the island of New Guinea.
Gale Virtual Reference Library : MonotremesThe order Monotremata (one-holed creatures) is comprised of two families, the Ornithorhynchidae, including the platypus, and the Tachyglossidae, including the long- and short-beaked spiny anteaters or echidnas. Monotremes are found only in Australia, Tasmania, and New Guinea. Monotremes are a derivative of an ancient mammal stock but there is no direct evidence of what it might have been.
Britannica School : Mammal Reproduction and ClassificationAll mammals reproduce through sexual intercourse. The female egg is fertilized internally. Mammals are divided into three subclasses according to the different ways in which the newborn develop from the fertilized egg. There are about 4,000 species of living mammals, arranged in about 120 families and 20 orders. The primitive monotremes of the subclass Prototheria reflect the reptilian origins of mammals. The duck-billed platypus and the echidna, or spiny anteater, are the only surviving species of this order. Like reptiles, they lay eggs rather than give birth to live young as is typical of all other mammals. After hatching, the young nurse on milk secreted from pores all over the mother’s nippleless chest.
Britannica School : MammalExcept for the monotremes (an egg-laying order of mammals comprising echidnas and the duck-billed platypus), all mammals are viviparous—they bear live young.
Britannica School : Placental MammalPlacental mammal, (infraclass Eutheria), any member of the mammalian group characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. The placentals include all living mammals except marsupials and monotremes.
Britannica School : MarsupialsMarsupial, any of more than 250 species belonging to the infraclass Metatheria (sometimes called Marsupialia), a mammalian group characterized by premature birth and continued development of the newborn while attached to the nipples on the mother’s lower belly. The pouch—or marsupium, from which the group takes its name—is a flap of skin covering the nipples. Although prominent in many species, it is not a universal feature. In some species the nipples are fully exposed or are bounded by mere remnants of a pouch. The young remain firmly attached to the milk-giving teats for a period corresponding roughly to the latter part of development of the fetus in the womb of a placental mammal (eutherian).
Gale Virtual Reference Library : MarsupialsMarsupials belong to the order Marsupalia, one of three subclasses of mammals (Metatheria). Marsupials are named for the marsupium, which means “pouch” in Latin; most female marsupials carry their young in pouches.
The order Marsupalia includes eight families, 75 genera, and 250 species. Marsupials are divided into two groups based on the number and shape of the incisor teeth. One group has numerous small incisors (the Polyprotodontia) and includes the carnivorous and insectivorous marsupial mice and American opossum. The second group has a few large incisors (Diprotodontia) and includes the herbivorous marsupials such as kangaroos and wallabies.
Britannica School : EchidnaEchidnas constitute the family Tachyglossidae, and their only living relative is the platypus. Together these animals constitute the mammalian order Monotremata
Australian Museum : EchidnaLike the Platypus, the Short-beaked Echidna is an egg-laying mammal or monotreme and lays one egg at a time. The eggs hatch after about 10 days and the young, emerge blind and hairless. Clinging to hairs inside the mother's pouch, the young echidna suckles for two or three months. Once it develops spines and becomes too prickly, the mother removes it from her pouch and builds a burrow for it. It continues to suckle for the next six months. -
Gale Virtual Reference Library : EchidnaThe spiny anteaters, or echidnas, make up four of the five species in the order Monotremata. These are primitive mammals that lay eggs like reptiles, but have hair and suckle their young. One species of spiny anteater, Tachyglossus aculeatus, lives in Australia, Tasmania, and New Guinea. The other three species (in the genus Zaglossus spp.) live only in New Guinea (further study may actually find them to be one species). The sixth monotreme species is the platypus (Ornithorhynchus anatinus), which bears little resemblance to the spiny anteaters, apart from the egglaying characteristic.
Britannica School : PlatypusThe platypus is most notable for having a broad, flat, rubbery snout or “bill” and for laying eggs instead of giving birth to live young as do most mammals. It has a squat body, short splayed legs, webbed feet, and a flat beaverlike tail.
Gale Virtual Reference Library : PlatypusThe platypus is classified in the order Monotremata (meaning single hole), consisting of two families and three genera. The families are Tachyglossidae (the spiny anteaters or echidnas) and Ornithorhynchidae (the platypus). There is only one species of platypus, Ornithorhynchus anatinus, which is comprised of four subspecies. All three species in the order Monotremata are considered primitive, combining mammalian features with those of lower orders of vertebrates such as reptiles. For example, monotremes are the only egg-laying mammals. In other mammals, the young are conceived within the female's body and are born alive. In monotremes, the eggs are fertilized internally, but are incubated and hatched outside the body. Monotremes, like all reptiles, also have a cloaca, a single opening through which feces, urine, and sperm or eggs pass. In other mammals, the cloaca is divided into an anus and genitourinary passages. Like other mammals, monotremes have fur, nurse their young with milk, and are warm-blooded.