1) (b) Mammal that lays eggs?
Answers
Your required answer :
- According to human research mammal can't lay egg.
- But in earth their are two mammals which are able to lay egg.
- Their names are :
- the duck-billed platypus
- the duck-billed platypus the echidna, or spiny anteater.
Answer:
duck-billed platypus and the echidna, or spiny anteater
Explanation:
Only two kinds of egg-laying mammals are left on the planet today—the duck-billed platypus and the echidna, or spiny anteater. These odd “monotremes” once dominated Australia, until their pouch-bearing cousins, the marsupials, invaded the land down under 71 million to 54 million years ago and swept them away.
Monotremes are prototherian mammals of the order Monotremata. They are one of the three main groups of living mammals, along with placentals and marsupials.
Class: Mammalia
Order: Monotremata; C.L. Bonaparte, 1837
Kingdom: Animalia
Infraclass: Australosphenida
Phylum: Chordata
Gestation period: Platypus: 10 – 14 days, Short-beaked echidna: 21 – 28 days, Western long-beaked echidna: 10 days
Reproduction
Monotremes reproduce by laying eggs. ... Monotreme reproduction is the least risky for the mother. However, eggs are harder to protect than is an embryo or a fetus in a pouch or uterus. Therefore, monotreme offspring may have a lower chance of surviving than the offspring of therian mammals.
Unique characteristics
Monotremes are different from other mammals because they lay eggs and have no teats. Monotremes are different from other mammals because they lay eggs and have no teats. The milk is provided for their young by being secreted by many pores on the female's belly.
Origin
A platypus tooth has been found in the Palaeocene of Argentina, so one hypothesis is that monotremes arose in Australia in the Late Jurassic or Early Cretaceous, and that some migrated across Antarctica to South America, both of which were still united with Australia at that time; however, several genetic studies ...
Birth
Monotreme young are born from small eggs covered by a leathery shell, and the tiny hatchlings are highly altricial. Monotreme young are completely dependent on milk as their source of nutrition, and the period of suckling is prolonged relative to gestation and incubation.