Scientists discovered a fossil in China that belongs to a previously unknown species of an obscure group of small dinosaurs,related to primitive birds such as the famous Archaeopteryx.It had feathers,but they seemed too insubstantial to be useful in flight.Then the scientists said they recognized the unusually long,rodlike bone extending from each of the two wrists: curving structures possibly supporting an aerodynamic membrane.These scientists are grouping the found fossil with birds based on ________ structures.
A)analogous
B)homologous
C)molecular
D)derived

Question

Quizplus · Accepted Answer

The scientists are using homologous structures to group the found fossil with birds. The presence of an unusually long, rod-like bone extending from each of the two wrists, which is a feature of birds, is a homologous structure. Homologous structures are similar in structure and developmental origin, indicating that they evolved from a common ancestor.

Scientists Discovered a Fossil in China That Belongs to a Previously