Precursor species are organisms that exhibit characteristics or traits that are similar to those of a more advanced or evolved species. They often represent an earlier stage in the evolutionary process, providing insight into how certain traits developed over time. Studying these species helps scientists understand the evolutionary history and relationships among different groups of organisms. For example, the Archaeopteryx is considered a precursor species between dinosaurs and modern birds. Its features, such as feathers and a wishbone, illustrate the transition from reptilian traits to those found in avian species, highlighting the gradual changes that occur through evolution.