> Could it be the archosauromorph ancestor of the
turtles!<
I somehow doubt it, but who knows. I thought turtles were thought to have a
strong ancestory to some Permian beasts, closer to mammals, who had migrated
the scapula into the ribcage.
No, no. The only animals other than turtles known to have done this are
some of the shelled placodonts like Henodus. You are thinking of
parareptiles (anapsids, more or less) like pareiasaurs and procolophonids,
which belong to a sister group to Eureptiles like lizards and archosaurs
but are no closer to the mammalian/synapsid line than dinosaurs are. The
big controversy in turtle origins is whether turtles arose from within the
parareptile clade (as a lot of anatomical evidence suggests) or the
eureptile clade (s DNA analysis suggests, though of course we have no
parareptile DNA). According to one of the experts on this, Dr Robert
Reisz, we simply do not have enough evidence to resolve this right now (or
so he told me).
--
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:ornstn@rogers.com