The Vertebrates 1Vertebrates Subphylum Vertebrata Internal jointed skeleton of vertebrates is living tissue that grows with the animal  Main axis of skeleton consists of vertebral columns and a skull that encloses the brain ­Cephalization is accompanied by sense organs ­Evolution of jaws and predation ­Amnion allows reproduction on land

2 Phylogenetic Tree of the Chordates

The Vertebrates 3 Vertebrate Features Living endoskeleton with vertebral column Closed circulatory system Paired appendages Efficient respiration and excretion High degree of cephalization Adapted to active lifestyles

4 Phylogenetic Tree of Reptiles

The Vertebrates 5Birds Characteristics of Class Aves  Feathers  Hard-shelled amniotic egg  Four-chambered heart  Often winged  Air sacs  Endothermic

Alligator vs Bird “hands & feet”

Archeopteryx fossil from Bavaria How is it different from modern birds?

Common features between archeopteryx and modern birds (in black)

Birds Today Approximately 9,000 – 9,600 species – Amphibia 4,184 –Reptilia 6,300 –Mammalia 4, orders, 174 families and 2044 genera Why do you think birds are so successful?

14 Bird Beaks – Why the difference? Why are these beaks different?