Page 35 - Demo

mya = millions of years agoDESIGNED FOR FLIGHTOver millions of years, pterosaurs, bats, and birds adapted the same five arm bones (color-coded here) into three different wing designs.The pteroid bone is only found in pterosaur fossils; it helped strengthen the front part of its wing.helped the pterosaur take off and move its wings.Lower arm boneAir sacs inside the wing bones made them very light.Three small, clawed fingers A very long fourth finger supported the wing.Wing skin (membrane)PTEROSAURQuetzalcoatlus Wingspan: 10 mBIRDWandering albatrossWingspan: 3.5 mBATGiant golden-crowned flying foxWingspan: 1.5 mBATSNOWQuetzalcoatlus northropiWingspan: 10 mFirst humans (homo sapiens) 200,000 years agoUnit 5A