Birds: the elements of ornithology . form a complete bony cup, thebottom of it being composed of membrane only. The three elements which thus make up each lateral half ofthe pelvis
Ichthyovenator, Jurassic Park Institute Wiki
Bird anatomy - Wikipedia
Dinosaur and bird pelvis - TalkRational Archive
Pelvis - Wikipedia
Response to “The Debate over Classification of Archaeopteryx as a Bird”
File:Jaculinykus holotype pelvic girdle.png - Wikimedia Commons
Bird anatomy - Wikipedia
LH-02-01, Prehistoric Wiki
Bird anatomy - Wikipedia