Parent: Laridae (Gulls)

└─ Thalasseus

└─── Thalasseus acuflavidus (Cabot's tern)

└─── Thalasseus bengalensis (Lesser crested tern)

└─── Thalasseus bergii (Swift tern)

└─── Thalasseus bernsteini (Chinese crested tern)

└─── Thalasseus elegans (Elegant tern)

└─── Thalasseus maximus (Royal tern)

└─── Thalasseus sandvicensis (Sandwich tern)