RE: Integument of Tyrannosaurus and other questions

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> Date: Thu, 21 Jun 2001 10:55:02 CDT
> From: Demetrios M Vital <vita0015@umn.edu>
>
> Dear all:
>
> I have three queries:
>
> One.  HP Holtz and others mentioned from the Armour Symposium a while back
> that tyrannosaurs may have been truly naked skinned.  How is this
> reconciled with the news of mosaic scales form a tyrannosaur tail?

I hope to answer that as part of my "what I did during summer break" work...
I'll be travelling to a couple of Canadian museums checking out reports of
tyrant skin impressions.  However, I'll check with Phil Currie and/or Darren
Tanke to see if they have papers on the subject in the work: if so, I'll let
them publish first.

> Assuming the animal is naked skinned, how would there be keratinous growth
> on cranial rugosities, like the nasals?  Would this look like a human's
> finger nails?

I do not see any reason why it would be any different in scale-less tyrants
than scaled ones.  The nasal region would be covered by a mass of
(presumably knobby) keratin.  Because I would imagine the material would be
thicker than finger- or toenails, I would expect it to be darker in
appearance.

> Two.  Who coined the phrase "abscence of evidence is not evidence os
> abscence"?  Was it HP Holtz?

Wished it was, but it predates me.  I think I first heard it in the 1980s.
It would be interesting to see if someone can track down the origin.

> I have used it often, and now friends in
> psychology and various other scholarly enterprises use the phrase often.
> Its spreading, and I don't think they realize it originated in
> paleontology
> (assuming it did).  Did it originate here?
>
> [ FWIW, I'm pretty sure I saw it in talk.origins years before the
>   dinosaur list was created, so no; it didn't originate here -- MPR ]

I have encountered it in several contexts: in UFO/paranormal/conspiracy
theory circles; in circles relating to the subject matter of talk.origins;
in classes on scientific methodology.  I can't recall at the moment the
context in which I first encountered it.  It might even come out of
criminology, for all I know...

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796