Search results
Results From The WOW.Com Content Network
The class Mammalia is divided into two subclasses based on reproductive techniques: egg-laying mammals (yinotherians or monotremes - see also Australosphenida), and mammals which give live birth . The latter subclass is divided into two infraclasses: pouched mammals ( metatherians or marsupials ), and placental mammals ( eutherians , for which ...
Monotremes (/ ˈ m ɒ n ə t r iː m z /) are mammals of the order Monotremata. They are the only group of living mammals that lay eggs, rather than bearing live young. The extant monotreme species are the platypus and the four species of echidnas. Monotremes are typified by structural differences in their brains, jaws, digestive tract ...
The second subclass is divided into two infraclasses: pouched mammals (the marsupials) and placental mammals. Australia is home to two of the five extant species of monotremes and the majority of the world's marsupials (the remainder are from Papua New Guinea, eastern Indonesia and the Americas).
Ornithorhynchoidea is a superfamily of mammals containing the only living monotremes, the platypus and the echidnas, as well as their closest fossil relatives, to the exclusion of more primitive fossil monotremes of uncertain affinity.
Echidnas and platypuses are the only egg-laying mammals, the monotremes. The average lifespan of an echidna in the wild is estimated at 14–16 years. Fully grown females can weigh about 4.5 kilograms (9.9 lb), the males 33% larger, at about 6 kilograms (13 lb). [12]
There are only five existing species of monotremes: the platypus and four species of echidna. “To a biologist, the idea that that branch could go extinct would be a great tragedy,” Kempton said.
Monotremes are mammals with a unique method of reproduction: they lay eggs instead of giving birth to live young. Two of the five known living species of monotreme occur in Australia: the platypus and the short-beaked echidna. The platypus — a venomous, egg-laying, duck-billed, amphibious mammal — is one of the strangest creatures in the ...
A Mammal, Bird or Something Else? Platypuses may have some duck-like characteristics, but they are a rare type of mammal called a monotreme. Monotremes differ from other mammals because they lay ...