My seminar At Periyar University Salem I'm Thomas chinnappan Keeranur Pudukkottai tamilnadu India @tcoftheworld @tcorganization

1. EVOLUTIO
N OF AVES
BY:
THOMAS CHINNAPPAN .A ,
M.SC.APPLIED GEOLOGY,
PERIYAR UNIVERSITY,
SALEM.

2. INTRODUCTION:
 Kingdom: Animalia
 Phylum : Chordata
 Class : Aves
 Birds evolved from
a group of theropod
dinosaurs in the
jurassic period.

3. 195 million of years ago
Birds evolve from reptiles

4.  The oldest known bird
fossil is Archaeopteryx
lithographica which has a
mix of “reptilian and
avian” features.
 Reptilian: long tail, teeth,
long clawed fingers
 Avian: feathers, ribs with
uncinate processes,
avian shoulder girdle

7. Evidence to link birds and
dinosaurs:
 Hundreds of similar skeletal features
 Hollow bones
 Feathers in some dinosaurs
 Lungs
 Heart
 Reproductive and sleeping posture

14.  A 75 million years old meat eating dinosaur
has a number of features that look more bird
like than dinosaur like providing evidence that
birds may have evolved from dinosaurs.

23. Most of the bird orders that we recognize
today had appeared
In early Oligocene, 35 million years ago,
Recent fossils discoveries of feathered
dinosaurs in china support this hypothesis

24. Fossil record:
 The fossil record of birds is not extensive: the
light, hollow bones of birds are not likely to
survive as fossils.
 However, a growing number of unusually well-
preserved fossil birds are contributing much to
our understanding of bird evolution.
 The oldest known fossil unambiguously
identified as a bird is still the dinosaur-like
Archaeopteryx, from the Solnhofen Limestone
of the Upper Jurassic of Germany.

25. Fossil record:
 However, it was not the only bird of the time.
 Very recently, another bird of almost the same
age was discovered in northeastern China, and
named Confuciusornis
 Confuciusornis resembles Archaeopteryx in
having wing claws, but unlike Archaeopteryx and
like modern birds, Confuciusornis lacked teeth.
 Modern birds continued to diversify through the
Cenozoic
 The Cenozoic bird fossil record consists largely of
isolated bones (although some nearly complete
skeletons have been recovered from certain
localities).

26. Fossil record:
 Suffice it to say that by the early Oligocene,
35 million years ago, most of the bird orders
that we recognize today had appeared.
 Recent fossils discoveries of feathered
dinosaurs in china support this hypothesis

27. Cretaceous birds

28. Tertiary birds
 Early to mid Tertiary (Paleocene into Miocene,
65-15 mya) was time of major adaptive
radiation of birds.
 By the mid-Paleocene get first appearance of
large, heavy-bodied, flightless predators to fill
bipedal carnivore niche vacated by the
disappearance of dinosaurs.

29. Pleistocene birds

30. Thank you