CLASS AVESSubclass Archaeornithes

Subclass Archaeopteryx• “ancient wing”• Extinct• Complete covering of body feathers• Long, straight bony tail

• Abdominal ribs present• Sternum was without any keel• Cerebellum small

• No beak• Teeth are present • Toes and fingers are clawed

NEORNITHES

This subclass is divided into 2 superorders,

Odontognathae,

and Neognathae.

• Toothed Cretaceous marine birds• The only odontognath ever recovered is a

marine bird, Hesperornis.

Odontognathae

Hesperornis• The wings were

vestigal, so it DID NOT FLY.

• But it SWAM AND DOVE for fish, catching the fish with sharp and CONICAL TEETH

carinatesratites

Neognathae

carinates (keeled)Can fly

(from ratis, "raft", referring to the flatness of the

sternum)Cannot fly

• Order Columbiformes. Doves• Order Pelecaniformes. Pelicans, cormorants,

etc.• Order Anseriformes. Ducks, geese, other

waterfowl.• Order Falconiformes. Hawks, eagles, vultures.• Order Galliformes. Grouse, quail, domestic

foul.• Order Psittaciformes. Parrots, paroquetes.• Order Passeriformes. Perching birds– up to 64

families, including song birds.• And about 15 other living orders.

ratites• They have small incompetent wings• But have powerful leg muscles that

enable them to run well• It is likely that their ancestors could fly

• Many are known only as fossils• The survivors are in danger of extinction

by humans.

Examples• ostriches• emus • cassowaries • rheas • kiwis • penguins

• Were nearly 4 m (13 ft)

• Laid eggs more than 30 cm (1 ft) in diameter

moas

Carinates

Carinatae were defi ned as all birds whose sternum (breast bone) has a keel (carina)

Carinates• The keel is a

strong median ridge running down the length of the sternum. – This is an

important area for the att achment of fl ight muscles.

• Largest living carinates is the Andean condor,

with a wingspread of 3m (10 ft) and weighing 15 kg(35 lbs)

• The Giant Teratorn (Teratornis), which lives in Argentina 5 million years ago

• Is thought to have been a flier

Had a wingspread of 7.5 m (25ft), weighed 360 kg (160 lbs) and measured 3.5m (11ft) from beak to tip of tail.

• Many are annual migrants.

• During migration birds move in mass flights, often at night and at an elevation of approximately 600 meters (2000 ft)

• Those destined for the same geographical location pass over approximately the same flyways year after year.

• Migration is associated with the reproductive cycle