Staurikoeoraptor

[Ron Dass <radass@orion.neca.com>]

While working with my son on a dinosaur report for his 6th grade class I came
across something that piked my curiosity. In Czerkas' book "Dinosaurs-A 
Global View" there is an illustration in the Triassic chapter with a caption
that described it as Staurikosaurus - the earliest known dinosaur. But I
seem to 
remember that Sereno in his Argentina expedition supposedly unearthed the 
earliest known dinosaur and called it Eoraptor. Are these two the same beast?
They both seem to be about the same size - 2m or so long (?) and both are
from Argentina and nowhere does Czerkas mention Eoraptor. What is the story
on these taxa?

And what about Lagosuchus? It seems to be a thecodont on the very brink of
dinosaurhood. How does it fall short?


                                TIA
                                   Ron Dass