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Nature Notes

Written by Tolly Beck
Tolly Beck is the horticulturist at Lasdon Park and Arboretum in Westchester County. She was formerly a horticulture educator for New York Botanical Gardens in the Bronx and Cornell Cooperative Extension of Rockland, NY.

Early Dinosaurs to Modern Birds

Today it is commonly accepted in the scientific community that birds are descendants of the Theropod group of dinosaurs. The conclusive proof of this was the discovery in 1860 in Germany of the then oldest known bird fossil (150 million years old). It is a fossil of Archaeopteryx, a member of the Theropod group.

Through that initial discovery, and more recent fossil discoveries, it has been found that some of the small meat-eating dinosaurs and modern birds share many features:

  • Hollow, thin- walled bones    • Exhibit brooding behavior
  • Capable of nest building   • Possess feathers   • Erect stance    • Capable of flight

Over time, the small Therapods grew smaller in size, lost their teeth and developed beaks. Their short arms eventually evolved into wings. Through these and other evolutionary changes, these small dinosaurs became modern birds. The birds that we see every day in trees, in yards, on birdfeeders and on windowsills are today classified as avian dinosaurs. They take us in flight back millions of years in time to the original… Age of the Dinosaurs.