Both are mammals, have a 4-chambered heart, body covering of fur or hair and both suckle their young.
Monotremes and marsupials are both types of mammals along with placental mammals
Monotremes, marsupials, and placental mammals.
No, birds are strictly avians. Mammals that lay eggs are considered monotremes.
There is no such thing as an "early mammal". Monotremes lay eggs, but there is a misconception that monotremes are the most primitive of mammals. Science has recently proven that monotremes are not primitive mammals at all.
Neither. Elephants are placental mammals, which form a different group of mammals from either the marsupials (pouched mammals) or the monotremes (egg-laying mammals).
Monotremes are mammals; therefore they have lungs, not gills.
No. Like most modern mammals, humans are placental mammals. The only living monotremes are the platypus and the echidna.
No, otters are not monotremes. Monotremes are a group of egg-laying mammals that include the platypus and echidnas. Otters are classified as carnivorous mammals in the family Mustelidae, which also includes weasels, badgers, and martens.
Oh yes - monotremes are mammals, which means that they have hair (which is unique to mammals) and also nurse their young from mammary glands. Monotremes do lay soft, rubbery eggs, which is a behavior that is unique among mammals but they are strictly mammals regardless.
No. Monotremes are mammals, and all mammals are vertebrates.
No. Egg-laying mammals are monotremes.
Monotremes are mammals that lay eggs, such as the Echidna and the Platypus.