Archaeopterygiformes

Taxobox
name = Archaeopterygiformes
fossil_range = Late Jurassic

---

image_width = 200px
image_caption = A model of "Archaeopteryx"
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Archaeopterygiformes
ordo_authority = Lambrecht, 1933
familia = Archaeopterygidae
familia_authority = Huxley, 1871
subdivision_ranks = Genera
subdivision ="Archaeopteryx" (type) "Wellnhoferia"

The Archaeopterygiformes were an order of early birds that lived during the Jurassic and possibly Cretaceous periods. They include one of the most well known and earliest birds known, "Archaeopteryx". Archaeopterygiformes are distinguished from other early birds by long bony tails, and in some species, by the presence of a hyperextendible second toe.

Taxonomy

The order Archaeopterygiformes contins the single family Archaeopterygidae. While the order has never been given a phylogenetic definition, a definition for Archaeopterygidae was proposed by Paul Sereno in 2005: the clade comprising all birds closer to "Archaeopteryx" than to Neornithes.Sereno, P. C. 2005. [http://www.taxonsearch.org/Archive/stem-archosauria-1.0.php Stem Archosauria—TaxonSearch] [version 1.0, 2005 November 7] ]

The family Dromaeosauridae, traditionally considered to be non-avian dinosaurs, have been included in this group by at least one author. Discoveries of a number of primitive forms have muddied the relationships of early birds, making it possible that "Velociraptor" and similar dinosaurs are actually members of Aves. Gregory S. Paul placed dromaeosaurids in Archaeopterygiformes for these reasons, though most cladistic analyses since have found them to be slightly more primitive, and therefore outside clade Aves.Paul, G.S. 1988. "Predatory Dinosaurs of the World." New York: Simon and Schuster. 464 pp.]

As its name suggests, "Protarchaeopteryx" was also originally referred to this order, but most paleontologists now consider it an oviraptorosaur. Other referred genera, like "Jurapteryx", "Wellnhoferia", and "Proornis", are probably synonymous with "Archaeopteryx" (the former two) or do not belong into this group (the last). "Jinfengopteryx" was originally described as an archaeopterygid, though it was later shown to be a troodontid.Ji, Q., Ji, S., Lu, J., You, H., Chen, W., Liu, Y., and Liu, Y. (2005). "First avialan bird from China ("Jinfengopteryx elegans" gen. et sp. nov.)." "Geological Bulletin of China", 24(3): 197-205.] Chiappe, L.M. "Glorified Dinosaurs: The Origin and Early Evolution of Birds." Sydney: UNSW Press.] cite journal |last=Turner |first=Alan H. |coauthors=Pol, Diego; Clarke, Julia A.; Erickson, Gregory M.; and Norell, Mark |year=2007 |title=A basal dromaeosaurid and size evolution preceding avian flight |url=http://www.sciencemag.org/cgi/reprint/317/5843/1378.pdf |format=pdf |journal=Science |volume=317 |pages=1378–1381 |doi=10.1126/science.1144066 ]

References