Classification of Class Aves

Class Aves is divide into two sub classes : I Sub class : Archaeornithes

II Sub class : Neornithes

Classification adapted from Sturer & Usinger (1957)

• Extinct Jurassic birds of Mesozoic era• Tail long with more than 13 caudal

vertebrae bearing retrices (tail feathers) arranged in two lateral rows

• Pygostyle absent• Vertebrae amphicoelous• Three digits ,metacarpals free each with a

claw• Teeth embedded in sockets in both jaws

I Sub class : Archaeornithes

Archaeopteryx

• Living as well as exinct birds• Tail is usually short ,ends in a pygostyle• The retrices are arranged in a semi-circle

around the pygostyle• Teeth are absent except in few forms• The meta carpals are fused with distal

carpals to form carpo-metacarpals• Claws absent in the fore limbs• The sternum is well developed and usually

provided with a keel or carina• Vertebrae are heterocoelous in living forms• Caudal vertebrae are 13 or less

II Sub class : Neornithes

Sub class Neornithes is divided into :

4 Super orders

I Odontognathae

II Impennae

III Palaeognathae

IV Neognathae

I Super order : Odontognathae

*Extinct cretaceous birds *Teeth present in furrows on jaws Example : Ichthyornis ,Hesperornis

Ichthyornis Hesperornis

II Super order : Impennae• Modern aquatic , flight less birds with

paddle-like wings or flippers• Feet are webbed • Example :Penguin

Modern, big-sized, flightless, running birds, without teeth. Wings vestigial or rudimentary, feathers devoid of interlocking

mechanism. The rectrices are absent or irregularly arranged but without hooked

barbules. Sternum without keel but raft-like. Uncinate processes are vestigial or absent. Tail vertebrae free. Pygostyle small or absent. Pectoral muscles poorly developed. Syrinx is absent. Male has a large and erectile penis; female has a clitoris. Young ones are precocious,born with feathers can move and feed on

their own just after hatching . Oil gland is absent, except in Titanus and kiwi Includes six orders. Ex: Apertyx (kiwis) & Rhea, Casuaris etc.

Super order : Palaeognathae (Ratitae)

Most modern, usually small-sized, flying birds. Wings well-developed; feathers with interlocking mechanism. Rectrices present and arranged regularly. Oil gland is present. Sternum with a well-developed keel. Uncinate processes are present. Pygostyle is present. Pectoral muscles large. Male has no copulatory organ. Young are altricial ,born without feathers ,need parental care Distributed all over the world. This super order is distinguished into 22 orders. Example: Sparrow, pigeon, parrot, fowl, cuckoo, duck,

kingfisher, pelicans, heron, crane, kite, owl, hawks, vulture etc.

Super order: Neornithes( Carinatae)

Class AVES Sub class

ARCHAEORNITHES NEORNITHES (Jurassic birds) (Modern and a few Ex: Archaeopteryx extinct post Jurassic birds) Super order

Odontognathae Ratitae Impennae CarinataeExtinct Modern Modern Mostly Cretaceous birds flightless aquatic modernJaws with teeth large birds flightless small birds Ex: Emu Ex;Penguin Ex: Parrot

Outline classification of Class Aves

Credits :Chordate Zoology by E.L.Jordan &

P.S.Verma2004 editionWikipedia