Which among the following is a living fossil?

Classification of $Reptilia$ is based on

$A$: The tortoise is classified under the class $Reptilia$.
$R$: The tortoise is a triploblastic,poikilothermic animal with epidermal scales.

The study of reptiles is known as:

In which of the following animals do sperm remain viable for a long period inside the female body?

Which among them has a moderately long and pointed snout and is very aggressive and dangerous for man?