 The greater crested tern 's closest relatives within its genus appear to be the lesser crested tern ( T. bengalensis ) , and the royal tern ( T. maximus ) . The DNA study did not include the critically endangered Chinese crested tern ( T. bernsteini ) but , as that bird was formerly considered to be conspecific with the greater crested tern as a synonym of the subspecies T. b. cristatus , it is presumably also very closely related . 
