sauropods and abelisaurids

[BPC.APA@email.apa.org (Considine, Blaise)]

I have 2 questions; 1 from me and 1 from my son that I could't answer.
1) can someone provide me with a sauropod lineage? Who came first sort of 
thing. This is a result of browsing through dinosaur books with my son 
and he noted that frequently different types of sauropods are shown 
together. While this is most likely for convenience, what is the timeline 
for sauropods? 
2) can someone explain more about the abelisaur(ids) mentioned by Stan 
and others while discussing S American dinos? They were related to the 
ceratosaurs, which were an early line of theropods...were abelisaurs the 
last in this line, more advanced, or what? 
Thank you, and someday (hopefully soon) I'll have enough free cash to buy 
some of these references you folks always mention.
Blaise Considine [bpc.apa@email.apa.org]