== Kilder ==
* Rudolf Schreiber, Anthony W. Diamond, Sven G. Nilsson, Staffan Ulfstrand (1987) ''Skydda fåglarna'', {{ISBN|91-7886-029-6}}
* Stafan Ulfstrand (2004). ''Jordens fågelfauna - ett Newtonskt försök till överblick'', "Vår Fågelvärld", nr. 2, udgivet af Sveriges ornitologiska förening.
* Per Ericson (i interview, 2006-09-19), ''Fåglarnas evolutionära historia kartlagd'', [[Tidningarnas Telegrambyrå]]
* [http://www.ucmp.berkeley.edu/diapsids/avians.html University of California, Berkeley: Are Birds Really Dinosaurs?] {{Webarchive|url=https://web.archive.org/web/20030806195929/http://www.ucmp.berkeley.edu/diapsids/avians.html |date= 6. august 2003 }} Citat: "...In fact, the evidence is overwhelmingly in favor of birds being the descendants of a maniraptoran dinosaur...Some researchers today do not agree that dinosaurs gave rise to birds, and are working to falsify this theory, but so far the evidence for the theory has swamped their efforts...."
* [http://www.birding.com/birdsdino.asp birding.com: Are Birds Dinosaurs?] {{Webarchive|url=https://web.archive.org/web/20041009213655/http://www.birding.com/birdsdino.asp |date= 9. oktober 2004 }} Citat: "...YES they are...NO they are not..."
* [http://tolweb.org/tree?group=Neornithes&contgroup=Aves Tree of Live web project: Neornithes, Modern Birds] {{Webarchive|url=https://web.archive.org/web/20030803184551/http://tolweb.org/tree?group=Neornithes&contgroup=Aves |date= 3. august 2003 }} Quote: "...Introduction...Whether modern birds are most closely related to dinosaurs or crocodylian ancestors is a point of current debate...."
* [http://news.bbc.co.uk/hi/english/sci/tech/newsid_1858000/1858574.stm BBCNews, 6 March, 2002, 'Modern' feathers found on Chinese dino] {{Webarchive|url=https://web.archive.org/web/20020603055357/http://news.bbc.co.uk/hi/english/sci/tech/newsid_1858000/1858574.stm |date= 3. juni 2002 }}
* [http://news.bbc.co.uk/1/hi/world/asia-pacific/4337888.stm 13 October 2005 BBC News: Bird-like dinosaur forces rethink] {{Webarchive|url=https://web.archive.org/web/20071018150013/http://news.bbc.co.uk/1/hi/world/asia-pacific/4337888.stm |date=18. oktober 2007 }} Citat: "...A rooster-sized [[dinosaur]] with a long, slender snout and wing-like limbs is forcing a rethink on bird evolution...The authors say the discovery of Rahonavis and Buitreraptor have long and wing-like forelimbs could imply that flight evolved twice, once in birds and once among this group of [[Gondwana]]n dromaeosaurs..."
* [http://taxonomicon.taxonomy.nl/TaxonTree.aspx?id=80129 Systema naturae 2000 (classification) – Taxon: Class Aves] {{Webarchive|url=https://web.archive.org/web/20120519041217/http://taxonomicon.taxonomy.nl/TaxonTree.aspx?id=80129 |date=19. maj 2012 }}
Geologi