Classification Of Class Aves 574d1b

Classification of Class Aves

Classification adapted from Sturer & Usinger (1957)

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

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II Sub class : Neornithes

I Sub class : Archaeornithes • •

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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

Archaeopteryx

II Sub class : Neornithes • • •

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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

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

Super order : Palaeognathae (Ratitae) 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: Neornithes( Carinatae)  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.

Outline classification of Class Aves  

Class AVES Sub class

ARCHAEORNITHES  (Jurassic birds)  Ex: Archaeopteryx

NEORNITHES (Modern and a few extinct post Jurassic birds) Super order

Odontognathae Ratitae Extinct Modern Cretaceous birds flightless Jaws with teeth large birds Ex: Emu

Impennae Carinatae Modern Mostly aquatic modern flightless small birds Ex;Penguin Ex: Parrot

Credits : Chordate Zoology by E.L.Jordan & P.S.Verma 2004 edition Wikipedia