http://en.wikipedia.org/wiki/Ornithischia

Ornithischia (/ɔrnɨˈθɪskiə/ or-ni-THISS-kee-ə) or Predentata is an extinct order of beaked, herbivorous dinosaurs. The name ornithischia is derived from the Greek ornitheos (ορνιθειος) meaning ‘of a bird’ and ischion (ισχιον) meaning ‘hip joint’. They are known as the ‘bird-hipped’ dinosaurs because of their bird-like hip structure, even though birds actually belong to the ‘lizard-hipped’ dinosaurs (the saurischians).

—-

WTH …

So there are two groups of dinosaurs, the bird-hipped dinosaurs and the lizard-hipped dinosaurs … and the birds are in the lizard-hipped group?

Get your act together, zoologists!

Yes, it’s one of those anomolies due to early terminology.

anomalies, sorry

> So there are two groups of dinosaurs, the bird-hipped dinosaurs and the lizard-hipped dinosaurs … and the birds are in the lizard-hipped group?

Yes. Annoying, isn’t it. Took me a while to figure that out.

Also starting to get annoying is the large number of dinosaurs given bird-like latin names, not all of which are at all closely related to birds. Such as the “ornithopoda” bird-feet, which are extremely distant from the birds.