HOW FEATHERS HELP BIRDS FLY

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Across
  1. 2. A small movable ________ was found in Anchiornis fossils.
  2. 3. This bone helped Anchiornis fold its arms to its ________.
  3. 5. Birds lift themselves by turning their ________ at a particular angle.
  4. 6. These feathers were similar to ________ bird feathers but had the same shape on both sides.
  5. 8. Paleontologists study theropod dinosaurs to find ________ about the origin of flight.
  6. 10. Feathers helped animals stay warm and attract mates. Over time, they began to help animals ________.
  7. 11. Scientists believe feathers evolved because they provided certain ________.
  8. 13. One side of the feather is thin and hard, while the other side is long and ________.
Down
  1. 1. Anchiornis had feathers on both its arms and ________.
  2. 2. Modern birds use the same bone to pull their wings toward their ________ as they fly.
  3. 4. Anchiornis is a 150-million-year-old ________.
  4. 7. The difference in air ________ allows birds to fly.
  5. 9. A bird’s feathers are not the same ________ on each side.
  6. 12. Feathered dinosaurs may have evolved flight by jumping from tree to ________.
  7. 13. Because of this, Anchiornis probably couldn’t ________.