"Inopinaves is a clade of neoavian birds recovered in a compressive genomic systematic study using nearly 200 species in 2015, that contains the clades Opisthocomiformes (Hoatzin) and Telluraves (core landbirds); the study shows that the Hoatzin diverged from other birds 64 million years ago. Previous studies have placed the Hoatzin in different parts of the bird family tree; however, despite its unusual and primitive morphology, genetic studies have shown the hoatzin is not as primitive or as ancient as once thought, and that it could be a very derived bird that reverted to or retains some plesiomorphic traits." - (Wikipedia (en) 18.09.2020)
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