Who are hoatzin close relations?

The hoatzin, a unique bird found in the Amazon rainforest, is closely related to the cuckoos, despite its distinct appearance and lifestyle. Molecular studies have shown that it shares a common ancestor with cuculiform birds, which also include the roadrunners and anis. The hoatzin is notable for its herbivorous diet and its young, which possess claws on their wings for climbing. Its unusual characteristics have led to ongoing interest in its evolutionary history and classification.