Historical placement as gamebirds is based mainly on phenetic considerations of external morphology , which are considered unreliable and generally dismissed today ; the gamebirds together with the waterfowl are classified as Galloanserae .
The hoatzin are not .
Historical placement as gamebirds is based mainly on phenetic considerations of external morphology , which are considered unreliable and generally dismissed today ; the gamebirds together with the waterfowl are classified as Galloanserae whereas the hoatzin are not .