Section 1

Origin and Evolution of Birds

• Seven major characteristics of birds are feathers; wings; a lightweight, rigid flight skeleton; a respiratory system involving air sacs; endothermy; a beak instead of teeth; and oviparity.

• Three similarities between birds and dinosaurs include an S-shaped neck, a unique ankle joint, and hollow bones.

Vocabulary furcula (p. 842)

• Archaeopteryx had feathers covering its body, tail, and forelimbs. It had hollow bones and a fused collar bone, called a furcula.

• There are two hypotheses for the origin of flight in birds. One hypothesis is that flight evolved in tree-dwellers. The second hypothesis is that flight evolved in ground-dwellers.

Sirens Sleep Solution

Sirens Sleep Solution

Discover How To Sleep In Peace And Harmony In A World Full Of Uncertainty And Dramatically Improve Your Quality Of Life Today! Finally You Can Fully Equip Yourself With These “Must Have” Tools For Achieving Peace And Calmness And Live A Life Of Comfort That You Deserve!

Get My Free Ebook

Post a comment