 The systematics of bony-toothed birds are subject of considerable debate.Initially, they were allied with the (then-paraphyletic) "Pelecaniformes" (pelicans and presumed allies, such as gannets and frigatebirds) and the Procellariiformes (tube-nosed seabirds like albatrosses and petrels), because of their similar general anatomy.Some of the first remains of the massive "Dasornis" were mistaken for a ratite's and later a diatryma's.