Final answer:
The Archaeopteryx is an ancient species that is considered both a dinosaur and a bird due to its mix of characteristics, such as teeth and feathers. It provides evidence for the theory that modern species share a common ancestor, supporting the idea of an evolutionary transition from dinosaurs to birds.
Step-by-step explanation:
The Archaeopteryx is an important fossil from the Jurassic period that exhibits characteristics of both dinosaurs and birds, making it a key specimen in understanding evolutionary relationships. As such, Archaeopteryx can reasonably be called a "feather dinosaur" due to its feathered appendages, thus the correct answer to the question is A. True. Additionally, Archaeopteryx supports the evolutionary theory that modern species share a common ancestor, which is reflected in the traits it shares with both the reptiles and the birds.
The Archaeopteryx is frequently discussed in the context of evolution because it is one of the oldest known examples that provides clear evidence for the transition from non-avian dinosaurs to birds. By studying Archaeopteryx fossils, scientists have been able to observe features typical of dinosaurs, such as jaws with teeth and a long bony tail, as well as features unique to birds like modified flight feathers.