Would a pigeon or a penguin make a better index fossil for the present day?

A pigeon would make a better index fossil for the present day due to its widespread distribution and adaptability to various environments, which allows for a more extensive range of fossil evidence. In contrast, penguins are primarily found in the Southern Hemisphere, limiting their geographical representation. Additionally, pigeons have a relatively short generation time and numerous species, making it easier to correlate their fossils with specific time periods. Overall, pigeons provide a broader and more relevant context for understanding current ecological conditions.