RE: A few very short questions

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> UNION4884@aol.com
>
>
> Hi,
> Some of you may remember that I asked a few questions a while back, for a
> dinosaur book I was writing for children. The book is in the last
> stages of
> pre-production, and the fact-checker has questioned 3 "facts".  I
> was hoping
> some of you might be able to assist me by confirming or negating these 3
> points.
>
>
> 1. I said dinosaurs are reptiles.
>  Is it true that dinosaurs are considered to be close relatives
> of reptiles,
> but in a class of their own?

While some (such as Bob Bakker) have advocated that position, it is not that
held by most people working on the relationships of dinosaurs to each other
and to other vertebrates.

To divide the question into two parts:
I) Dinosauria is part of Reptilia, so dinosaurs are reptiles.
II) The concept of a "Class" (and "Order" and "Family" and so on) has been
abandoned by most working systemicists.

You can check out (among MANY potential sources) the chapter by myself &
Mike Brett-Surman on dinosaur taxonomy & systematics in Farlow &
Brett-Surman's _The Complete Dinosaur_.

> 2. I  said the smallest pachycephalosaur was 20 inches long (which I had
> read, but I can't remember where.)   Is this correct?  If so, does anyone
> have a reference for this?

Is this _Micropachycephalosaurus_ (which has been published) or the dwarf
North American form (which has not been formally described)?

> 3. I said that  scientists think the frills  of some dinosaurs may have
> changed color.   Is this correct?   Does anyone know who the
> proponents of
> this theory are?

Although this idea has been suggested (Bakker 1986 (The Dinosaur Heresies),
for example), it is *pure speculation*.  We cannot test this hypothesis at
present.

> Thanks for any assistance you can provide.
>
> Barbara Saffer, Ph.D.  (science writer)

Hope this helps.

                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): 301-314-7843