The name of $Pithecanthropus$ $erectus$ (often referred to as $Pithecanthropus$) is associated with which of the following?

$A$: The brain reaches between $75$ and $80$ percent of its adult size within the first two years,and its full size at the age of $6$ years.
$R$: From an evolutionary point of view,the human gestation period is believed to be shortening.

The first mammals were like $A$. Their fossils are small-sized. Mammals were $B$ and protected their unborn young inside the mother's body. Choose the correct option for $A$ and $B$ to complete the given $NCERT$ statement.

What was the cranial capacity of $Australopithecus$ (in $, c.c.$)?

Which one of the following pairs is mismatched regarding their appearance in human evolution?

Among the following,which is the most recent?