Final answer:
The claim that no dinosaur had feathers or hair is false, as evidenced by the fossil of Archaeopteryx and others, which display feathers, supporting the theory that modern species share a common ancestor.
Step-by-step explanation:
The statement that there is no conclusive evidence that any dinosaur was covered with hair or feathers is false. Paleontological evidence, such as the fossil of Archaeopteryx, shows that some dinosaurs did have feathers. Archaeopteryx is an important fossil because it displays characteristics of both reptiles and birds, most notably the presence of feathers, which are modified for flight. This supports the evolutionary theory that modern species share a common ancestor, providing a connection between dinosaurs and birds. Other older feathered dinosaur fossils have been discovered, although their feathers may not have had the same structure as modern flight feathers.
There is evidence that some dinosaurs were covered with feathers. One example is Archaeopteryx, a fossil of an organism that has features of both reptiles and birds, including evidence of feathers. This suggests support for the aspect of evolutionary theory that modern species share a common ancestor.