Rhynchocephalians disappeared from North America and Europe after the Early Cretaceous, and were absent from North Africa and northern South America by the early Late Cretaceous. The cause of the decline of Rhynchocephalia remains unclear, but has often been suggested to be due to competition with advanced lizards and mammals. They appear to have remained diverse in high-latitude southern South America during the Late Cretaceous, where lizards remained rare, with their remains outnumbering terrestrial lizards by a factor of 200. An indeterminate rhynchocephalian is known from the latest Cretaceous of Insular India. The youngest known remains of rhynchocephalians outside of New Zealand are those of Kawasphenodon peligrensis from the early Paleocene (Danian) of Patagonia, shortly after the Cretaceous–Paleogene extinction event. Indeterminate sphenodontine jaw fragments bearing teeth are known from the early Miocene (19-16 million years ago) St Bathans fauna, New Zealand, that are indistinguishable from those of the living tuatara. It is unlikely that the ancestors of the tuatara arrived in New Zealand via oceanic dispersal, and it is thought that they were already present in New Zealand when it separated from Antarctica between 80 and 66 million years ago. Gallery Phylogeny The following is a cladogram of Rhynchocephalia after Rauhut et al., 2012. References Further reading External links . Taxa named by Albert Günther Tetrapod orders Extant Middle Triassic first appearances Ladinian first appearances Middle Triassic taxonomic orders Late Triassic taxonomic orders Early Jurassic taxonomic orders Middle Jurassic taxonomic orders Late Jurassic taxonomic orders Early Cretaceous taxonomic orders Late Cretaceous taxonomic orders Paleocene taxonomic orders Eocene taxonomic orders Oligocene taxonomic orders Miocene taxonomic orders Pliocene taxonomic orders Pleistocene taxonomic orders Holocene taxonomic orders