Question

How are sub-phylum gnathostomata classified?

Answer 1

Sub-phylum Gnathostomata is further classified into two superclasses namely:

1. Pisces: These include animals having a streamlined body covered with scales and using gills to intake oxygen dissolved in water. Examples - Rohu, Tuna, Shark
2. Tetrapoda: They have four limbs for locomotion and are further divided into four classes.

Pisces is divided into two classes, namely,
1. Class Chondrichthyes: Their skeleton is completely cartilaginous and have placoid scales. Example - Sting ray, Saw fish
2. Class Osteichthyes : They have a bony skeleton and have cycloid scales. Example - Sea horse, Rohu

Tetrapoda is divided into four classes, namely

1. Class Amphibian: Amphibians are cold-blooded vertebrate creatures with gills that live in water as larvae but breathe air as adults. Example - Bull frog , salamander
2. Class Reptilian: Reptiles are cold-blooded, air-breathing animals with scaly bodies rather than hair or feathers. Example - Snakes, lizards
3. Class Aves: Birds are warm-blooded animals characterized by their feathered bodies and modified forelimbs that function as wings. Example - Peacock, pigeon
4. Class Mammalia: Animals are a category of vertebrate animals whose young are fed milk from the mother's particular mammary glands. Example- Humans, monkey