Final answer:
Pachychepalosaurs are not mentioned, but pterosaurs and dinosaurs had different characteristics, making the statement false.
Step-by-step explanation:
Pachychepalosaurs are not mentioned in the provided information, so it is difficult to determine their specific characteristics. However, pterosaurs are mentioned, and they were distinct from dinosaurs. While pterosaurs had adaptations for flight, such as hollow bones and wing membranes, the dinosaurs were a diverse group of terrestrial reptiles with many species and various traits, including quadrupeds and bipeds, carnivores and herbivores. Some dinosaurs were also likely endothermic and displayed parental care. Therefore, pterosaurs and dinosaurs had different characteristics, making option b. false.