Classification of vertebrate zoology ( Class Aves/Birds)

Origin Of Birds/Aves;

The birds are derived from Greek word. Ornis as well from Latin word Aves.

General Character of Class Birds/Aves;

Birds are warm-blooded vertebrates and adopted for aerial mode of life. They are having epidermal exoskeleton in the form of feathers all over the body and having few scales on the limbs. They are having flexible neck and their jaws produced into toothless beak. Their forelimbs are modified into the wings and hind limbs use to bear the body weight and adopted for walking, perching or swimming and bear claws. They are having pneumatic endoskeleton and monocondylic skull without distinct sutures between the bones. Their sternums is keeled and respiratory system much extended and supplemented with air sacs. They are having well develop larynx and capable to sing and produce melodious voices. Birds are having heart with four chambered, only right systematic arch persist in the adult and renal portal system are not well developed. They are having brain with large cerebellum, cerebral hemispheres and twelve pairs of cranial nerves. Birds are said to be egg laying animals. Their eggs are large, yolky and shelled. Embryo develops foetal membranes and yolk sac placenta. Birds are considered to be nestling habit and taking care of eggs and young ones.

Classification of birDS

The birds are classified into two subclasses;

Subclass 1. Archaeornithes;

In this subclass includes all fossils birds from Jurassic period.such as; Archeopteryx & Archaeornis.

Subclass 2. Neorinthes;

Its include living as well as few extinct birds. The subclass Neorinthes are further divided into four superorder.

Superoder 1. Odontognathae;

As the named indicates its include toothed birds.it is differentiated into two orders such as;

·        Order 1. Hesperornithiforms
·        Order 2. Ichthyornithiforms

Superoder 2. Palaeognathae or Ratitae;

The birds in this order are said to be large size which can’t fly but can run. It is further divided into the six orders;

·        Order 1. Struthiorniformes
·        Order 2. Casuariiformes
·        Order 3. Apterygiformes
·        Order 4. Rheiformes
·        Order 5. Dinornithiformes
·        Order 6. Aeppornithiformes (Extinct)

Superoder 3. Impernnae;

Its include flightless birds that are adopted to aquatic mode of life. Their forelimbs are modified into flippers for swimming.

Superoder 4. Neognathae or Carinatae;

In this order includes modern and widely distributed birds. This suborder are futher divided into the 22 orders.