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Re: Syntarsus feathers



Rob Gay wrote-

> Well, despite some of the drawings I have done in the past for fun, I
think
> the reality is that _Coelophysis_ and its relatives didn't have feathers.
By
> use of inference and phylogenetic bracketing, we can look at
_Herrerasaurus_
> (which has t-shaped neural arches, often associated with the support of
> dermal ossicles), _Ceratosaurus_, and _Carnotaurus_, which both have
scutes,
> and say that other ceratosaurs probably had scutes, and lacked feathers
> (though, admitadly, the two are not mutually exclusive). There are also
> apparently little, paper-thin round "scutes" that occasionally appear in
Ghost Ranch blocks...

I would agree that coelophysoids probably didn't have feathers.  The new
Psittacosaurus specimens bring up interesting issues involving the presence
of filaments though.  I assume the "t-shaped neural arches" you're referring
to are the expanded spine tables of the dorsal neural spines?  If so,
remember these are present in troodontids and dromaeosaurids as well, but
not Ceratosaurus.  There's no proof that Carnotaurus had dermal ossicles-
the large scales are preserved as impressions so we don't know if they had a
bony core or not.  I would think with the many articulated Coelophysis
specimens known we would have some articulated osteoderms if they were
originally present, not just isolated elements occasionally preserved in
some blocks.

Mickey Mortimer