The Archosauria reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Archosauria

For thoughtful child sponsors
Archosauria
Scientific classification
Domain:Eukaryota
Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebrata
Infraphylum:Tetrapoda
Microphylum:Amniote
Nanophylum:Sauropsid
Superclass:Diapsida
Class:Archosauria
Subclasses
Pseudosuchia
Ornithosuchia

Archosauromorpha, to attain a higher level of activity, developed a four chambered heart - this is their shared characteristic. The class Archosauria contains two chief subclasses: pseudosuchia and ornithosuchia.

On a lighter note, the creature after which ornithosuchia is named, the Ornithosuchus has since been determined a pseudosuchia.

Animals that are alive today that are in this class include alligators and crocodiles.