For the most part, modern birds bear little physical resemblance to the dinosaurs from which they evolved. An exception to this rule is the ancient heron family. Fossils attributable to the genus Ardea go back as far as the upper Miocene, about seven million years ago, and it's likely that the family arose in the Paleocene, 55-65 million years ago. The Cretaceous Gallornis, which is thought to be the closest known relative to the common ancestor of all living birds, probably looked a lot like a Great Blue Heron. When watching a heron stalk its prey, it's easy to visualize its relationship to the coelurosaurian theropod dinosaurs that are thought to have given rise to all modern birds.
After Archaeopteryx, the fossil record suggests that birds diversified rapidly, with their toothed beaks and clawed fingers. While most of the bird lineages that arose during the Cretaceous died out, some of them survived and gave rise to the wonderful diversity of birds we see today.
|
keywords (defined):
|
|
keywords (additional): |
herons, Gallornis |
|---|
|
