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RE: Eodromaeus, new basal theropod from Triassic in Argentina
At the point to which "extent" becomes a variable, pure speculation leaves
the question unanswerable as to "Which dinosaurs had what type of integumental
covering?" We cannot answer this question without direct evidence, and this is
lacking in depositions which fail to preserve anything but the bones.
I would also remind readers that the general artistic trend, as promoted by
Greg Paul, is to render theropods half-and-half squamous and "fuzzy," or
squamous and plumed when it comes to taxa he's argued to be derived from
*Archaeopteryx*-type "protobirds." This artistic device is based on little
_hard_ evidence, although some exists:
*Juravenator* is known from material with both "fuzzy" and squamous specimens;
Dave NGMC 91 has regions of the snout and limbs that do not appear to possess
*Scansoriopteryx*' holotype has impressions of squamous skin as well as
traces of preserved "fuzz."
Theagarten Lingham-Soliar argues that the "quills" in *Psittacosaurus* sp.
are coincident with traces of squamous skin, although he objects to the
identification of the nature of the "quills" being related to "fuzz."
So there is evidence in some specimens of both integument types, while in
others it may be argued at least that ontogeny may play a role.
Jaime A. Headden
The Bite Stuff (site v2)
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion
> Date: Sat, 15 Jan 2011 14:59:16 -0300
> Subject: Re: Eodromaeus, new basal theropod from Triassic in Argentina
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> To: firstname.lastname@example.org
> CC: email@example.com; firstname.lastname@example.org
> As long as both squamous integument and "fuzz" may be reconstructed for
> dinosaurs on the basis of bracketing (the first because of the state in
> crocs, bird feet, ornithischians, sauropods, theropod Carnotaurus; the
> second because of the state in pterosaurs, small ornithischians, and
> coelurosaurs), it may be inferred that both were present, because they
> can be both present as long as the organism is not covered by only one
> integumental type. The question would be to which extent each
> integumental type was present, which seems difficult to ascertain as we
> often do not have complete integumental coverings. Of course, size may
> explain the extent of each coverage.