Simplify the following text for a Grade 11 native English-speaking person.
Original: They are known as the ` bird-hipped ' dinosaurs because of their bird-like hip structure , even though birds actually descended from the ` lizard-hipped ' dinosaurs ( the saurischians ) .
Simplified: They are known as the ` bird-hipped ' dinosaurs because of their bird-like hip structure , even though bird actually descended from the lizard-hipped ' dinosaurs the saurischians .