The Sibley-Ahlquist taxonomy still allied the loons with the grebes in its massively paraphyletic "Ciconiiformes", and it is almost certain that the relationships of loons lie with "some" of the orders placed therein. Namely, other recent authors have considered loons to share a rather close relationship with seabirds such as penguins (Sphenisciformes), tubenoses (Procellariiformes), waders (Charadriiformes) – and perhaps the newly discovered clade Mirandornithes which unites grebes (Podicipediformes) and their closest living relatives, the flamingos (Phoenicopteriformes). It is perhaps notable that some early penguins had skulls and beaks that were in many aspects similar to those of the living and fossil Gaviiformes.