Which of the following is an example of Prototheria?

Prototherians are considered to be the most primitive mammals, only restricted in Australia and its neighbouring islands. Example: Duck Billed platypus, Echidna. Therefore, this is the correct option.

Why is Prototheria called Monotremata?

Monotremes /ˈmɒnətriːmz/ are members of the prototherian order Monotremata. They are one of the three main groups of living mammals, along with placentals (Eutheria) and marsupials (Metatheria). The name monotreme derives from the Greek words μονός (monós ‘single’) and τρῆμα (trêma ‘hole’), referring to the cloaca.

Who is called as Prototheria?

: a subclass of Mammalia that is coextensive with Monotremata or in some classifications includes both Monotremata and Allotheria and that is represented in the recent fauna solely by the egg-laying platypus and echidnas.

What are Prototheria and theria?

Living members of the class Mammalia belong to one of three groups: the egg-laying Monotremata (formerly designated as the Prototheria); and in the subclass Theria, the marsupials (Metatheria) and the eutherian (placental) mammals (the Eutheria).

What are the characteristics of Prototheria?

Subclass Prototheria Primitive; egg-laying; hair; mammary glands without nipples; pectoral girdle; separate oviducts that open into cloacal chamber that is shared with excretory ducts; oviparous.

What are the 3 subclasses of mammals?

There are three subclasses of mammals: prototheria, metatheria and eutheria. Monotremata is the only order in the prototheria subclass. Monotremes are so different from other mammals that scientists think they may be descended from a separate mammal-like reptilian stock. The duck-billed platypus is in this order.

How do Prototheria Metatheria and eutheria differ?

The key difference between Prototheria Metatheria and Eutheria is that Prototheria refers to egg-laying mammals while Metatheria refers to marsupials that give birth to partially developed young ones, and Eutheria refers to placental mammals that give birth to well-developed young ones.

What is Prototheria short note?

The Prototheria is a former subclass of mammals, now no longer in use. The name comes from Greek prōtos means ‘first’, and thēr, ‘beast’. The only surviving animals in this subclass are the Monotremes. There are two other subclasses, the Metatheria and the Eutheria. All the other mammals are Eutherian.

What is theria in biology?

Theria is a subgroup of Class Mammalia. It consists of metatherians (marsupials) and eutherians (true placental mammals) that give birth to live young as opposed to non-therian mammals that lay eggs.

Is Prototheria viviparous?

The class Mammalia is divided into subclass Prototheria, Metatheria, and Eutheria. Complete answer: Eutherian mammals are viviparous animals, in which the fetus develops inside the uterus of the mother.

What are typical Prototherian characters?

Body is small , covered by hairs and spines. Snout produced into beaks. External ears inconspicuous or absent. Tail present or absent .

What animals belong to the class Prototheria?

Rodentia (Rats, guinea pigs, squirrels, beavers, chinchillas, porcupines, capybaras and relatives)

Are there any surviving species of Prototheria in the world?

There are only three surviving rare species groups of Prototheria . These are the Australian platypus and 2 echidna (spiny anteater) species of Australia and New Guinea. (length = 7 min s. 30 secs.) To find out a little more about the strange lives of monotremes, select the “Echidna Reproduction” button below:

What are the orders of the Prototheria subclass?

Prototheria (/ ˌproʊtəˈθɪəriə, – toʊ -/; from Greek πρώτος, prōtos, first, + θήρ, thēr, wild animal) is a paraphyletic subclass to which the orders Monotremata, Morganucodonta, Docodonta, Triconodonta and Multituberculata have been assigned, although the validity of the subclass has been questioned.

When did prototherians split from the other mammals?

Egg-Laying Mammals or Prototherians. Prototherians probably split from the lineage leading to other mammals sometime in the Mesozoic. They retain many characters of their therapsid ancestors (for example, a complex hip structure, laying of eggs rather than bearing live young, have one opening for excretion and urination etc.).

How are Prototheria and metatherian related to each other?

This group split from the ancestors of Eutherian and Metatherian a long time before those became placental and therefore more adapted to diverse climates and harsher environments. This group looks like a combination of reptiles, birds and “true mammals”.