From the “containing group” link on the Diapsida page.    From Wordnik.com.  [Drawing a Line in the Academic Sand - The Panda's Thumb] Reference

In cladistics, Aves is nested in Reptilia through Diapsida.    From Wordnik.com.  [A Disclaimer for Behe?] Reference

We further hypothesize that the descendents of the common ancestor of the Sauropsids form two groups: Testudina and Diapsida.    From Wordnik.com.  [A Disclaimer for Behe?] Reference

(Btw, Lenny (I think?) let me know that turtles and their relatives should also be put in the Diapsida branch rather than the Anapsida.).    From Wordnik.com.  [Drawing a Line in the Academic Sand - The Panda's Thumb] Reference

The Tree of Life page plays with Diapsida a bit too, juggling two minor clades to place them outside Diapsida where Major Features of Vertebrate Evolution places them within Diapsida.    From Wordnik.com.  [Down with phyla! (episode II) - The Panda's Thumb] Reference

And I read a good deal of the latest issue of the Journal of Vertebrate Paleontology, including "Redescription and Phylogenetic Relationships of Doswellia kaltenbachi (Diapsida: Archosauriformes) from the Upper Triassic of Virginia," "Utility and Validity of Middle and Late Triassic 'Land Vertebrate Faunachrons,'" and "The Skull of Teleosaurus cadomensis (Crocodylomorpha; Thalattosuchia), and Phylogenetic Analysis of Thalattosuchia.".    From Wordnik.com.  ["A forest's son, a river's daughter..."] Reference

OLSON (1903) The reptilian subclasses Diapsida and Synapsida and the early history of the Diaptosauria.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The taxonomy and paleobiology of the Late Triassic (Carnian-Norian: Adamanian-Apachean) drepanosaurs (Diapsida: Archosauromorpha: Drepanosauromorpha).    From Wordnik.com.  [Hairy Museum of Natural History] Reference

However, both those groups are extinct, so you’re pretty safe if you just think of Diapsida as “lizards + crocodilians + birds + all their extinct relatives.”.    From Wordnik.com.  [Down with phyla! (episode II) - The Panda's Thumb] Reference

Lower branch: Amniota - Reptilia - Diapsida.    From Wordnik.com.  [Drawing a Line in the Academic Sand - The Panda's Thumb] Reference