Synapsids weren't reptiles?

[Dora Smith <villandra@austin.rr.com>]

I am looking at an article in the March 2008 issue of New Scientist.   It's 
a discussion about missing links or something; I seem to be missing the 
first page.

It says that synapsids "were once" called mammal-like reptiles, bot no more, 
"because synapsids are not reptiles -- the two groups evolved in parallel 
from a common ancestor".

What was the common ancestor - an amphibian?

Yours,
Dora Smith
Austin, TX
tiggernut24@yahoo.com