Sauriurae (meaning "lizard tails" in

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

) is a now-deprecated subclass of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s created by

Ernst Haeckel Ernst Heinrich Philipp August Haeckel (; ; 16 February 1834 – 9 August 1919) was a German zoologist, natural history, naturalist, eugenics, eugenicist, Philosophy, philosopher, physician, professor, marine biology, marine biologist and artist ...

in 1866. It was intended to include ''

Archaeopteryx ''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird'') is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaîos''), meaning "ancient", and (''ptéryx''), meaning "feather" ...

'' and distinguish it from all other birds then known, which he grouped in the sister-group

Ornithurae Ornithurae (meaning "bird tails" in Greek) is a natural group that includes modern birds and their very close relatives such as the ichthyornithines and the hesperornithines. This clade is defined in the ''PhyloCode'' by Juan Benito and collea ...

("bird tails"). The distinction Haeckel referred to in this name is that ''Archaeopteryx'' possesses a long, reptile-like tail, while all other birds known to him had short tails with few vertebrae, fused at the end into a

pygostyle Pygostyle is a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main component o ...

.Haeckel, Ernst. (1866) "Generelle Morphologie der Organismen" Berlin: Georg Reimer. 462 pp. The unit was not much referred to, and when

Hans Friedrich Gadow Hans Friedrich Gadow (8 March 1855 – 16 May 1928) was a Germany, German-born ornithologist who worked in United Kingdom of Great Britain and Ireland, Britain. His work on the classification of birds based on anatomical and morphological characte ...

in 1893 erected

Archaeornithes The Archaeornithes, classically Archæornithes, is an extinct group of the first primitive, reptile-like birds. It is an evolutionary grade of transitional fossils, the primitive birds halfway between non-avian dinosaur ancestors and the derived m ...

for basically the same fossils, this became the common name for the early

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

-like

grade Grade most commonly refers to: * Grading in education, a measurement of a student's performance by educational assessment (e.g. A, pass, etc.) * A designation for students, classes and curricula indicating the number of the year a student has reach ...

of birds. Ji Qiang and Larry Martin have continued to refer to the Sauriurae as a valid natural group.Ji, Q., and Ji, S. (1996). "On discovery of the earliest bird fossil in China and the origin of birds." ''Chinese Geology'' 10 (233): 30-33. However, researchers like Jacques Gauthier (2001)Gauthier, Jacques, de Queiroz, Kevin. (2001) "Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name 'Aves'". in "New Perspective on the Origin and Evolution of Birds: Proceedings of the International Symposium in Honor of John H. Ostrom" Yale Peabody Museum. Yale University. New Haven, Conn. USA and

Julia Clarke Julia Allison Clarke is an American paleontologist and evolutionary biologist who studies the evolution of birds and the dinosaurs most closely related to living birds. She is the John A. Wilson Professor in Vertebrate Paleontology in the Jackso ...

(2002)Clarke, Julia A., Norell, Mark. A. (2002) "The Morphology and Phylogenetic Position of Apsaravis ukhaana from the Late Cretaceous of Mongolia" American Museum Novitates, No. 3387, American Museum of Natural History, New York, NY 10024. have found that fossils found after Haeckel's time have bridged the gap between long and short-tailed

Avialae Avialae ("bird wings") is a clade containing the only living dinosaurs, the birds, and their closest relatives. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to Deinonychosauria, deinonychosaurs, though ...

. In their view, any grouping of avialans with long tails must exclude some of their descendants—making Sauriurae a

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

and, thus, an invalid group under current systems of

phylogenetic nomenclature Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional method, by which taxon names are defined by a '' type'', which c ...

References

{{reflist

References

See also