Re: really big question

[Dino Guy Ralph <ralph.miller@alumni.usc.edu>]

A naked throat does not a naked body make.  It is typical for feathered 
animals (i.e. pelicans) to have naked distensible gulae.

If you ever get the opportunity, see the documentary, "The Odyssey of Life." 
This film includes a sequence with scavenging beetles devouring a bird 
carcass, sped up for your viewing pleasure.  The very first items to be 
removed and scattered to the winds are the contour feathers that cloak the 
body.  At this stage, the carcass is but a (slightly chewed up) naked body 
with flight feathers.  The remiges and rectrices (flight feathers), being 
more firmly attached and not being of particular interest to the beetles, 
remain even while the body is skeletonized.  So you see, durability and 
biotic activity are factors in the selective utilization of bird tissues.

The Liaoning specimens (from a different Lagerstatten, of course) apparently 
preserve dark traces of feathers where the durable dark pigment, melanin, 
was present, and this seems to be the case not only on the feathered 
dinosaurs, but also on the arthropods.  This explains why "Dave," the 
juvenile sinornithosaur, features ambiguous feathers which present only the 
very tips of the barbs in many cases.  But these barb tips weren't just 
floating in the midair -- they had to be attached to the rest of the barbs 
and, in some cases, to the rachides.  In this case, the differential 
integrity of proteins plays a part in determining how an animal's body will 
ultimately be preserved.  Had Dave sported white feathers, there might not 
have been any traces of the feathers.  Among extant birds, the melanin-rich 
portions of feathers may persist while lighter portions wear away.

Thus far, the best evidence for tubercular integument in theropods occurs on 
_Carnotaurus_ and (according to an abstract in last year's SVP meeting 
volume) _Allosaurus_.  No coelurosaur is known to have sported such a pelt. 
If you accept that ornithomimids were coelurosaurs no more basal than 
compsognathids, then you must conclude that it is probable that they, too, 
were feathered.

> From a metabolic standpoint, the ornithomimids are excellent candidates for 
endothermy.  Their skeletons are better adapted for speed than those of any 
contemporary terrestrial animals.  And insulation is a very useful 
adaptation for promoting energy efficiency in endotherms.

Fess up, Cliff -- you just don't want to have to sculpt feathers.  They're a 
pain the butt!  You are, of course, free to choose not to give your 
ornithomimids feathers, but this puts you at risk of producing a sculpture 
that is outdated (just like the scaly "Jurassic Park" and "Walking With 
Dinosaurs" dromaeosaurs) as soon as a good, feathered specimen turns up in 
the Gobi or Liaoning.  It's a gamble either way, but the last time I 
checked, my bookie was giving the fuzzy look much better odds!

--------
"Dino Guy" Ralph W. Miller III
Docent at the California Academy of Sciences
proud member of the Society of Vertebrate Paleontology

"Get down!"