Question

In which animal, there is a post- anal tail as well as heterodont teeth?

Answer 1

Hint: The post- anal tail is the posterior elongation of the body, extending beyond the anus. The tail has the skeletal elements and muscles, which give a source of locomotion in aquatic species. Heterodont teeth are a group of teeth of varied shapes which will serve different functions (e.g., incisors, canines, and molars).

Complete step by step answer:
Postanal tails are present in almost all vertebrates. Heterodont teeth (teeth differentiated into 4 types of teeth incisors, canines, molars, premolars) are only present in mammals.
Scorpion being a non- chordate lacks both.
Cobra and Krait are also chordates but they are reptiles hence lack heterodont teeth.
Elephants classify both the conditions of being mammals also as chordates.
- Nonmammalian vertebrates are typically homodont, meaning that each one of the teeth is of a similar shape, as in sharks and crocodiles. Mammals are typically heterodont. This means that they have different forms of tooth shapes. Most mammals have incisors, canines, premolars, and molars.
- The post- anal tail is the posterior elongation of the body, extending beyond the anus. The tail contains skeletal elements and muscles, which give rise to the locomotion in aquatic species. In some terrestrial vertebrates, the tail present helps in balance, courting, and signalling when danger is found nearby.
So the animal with both Heterodont teeth and the post- anal tail is 'Elephant'.

Note: Animals belonging to phylum Chordata have the presence of the notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. They have a post- anal tail and closed circulatory system. Whereas earthworms, cockroaches, scorpions and other lower invertebrates like this do not belong to vertebrates and thus, do not possess a post- anal tail and so they are called invertebrates.