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Re: First fossils of Tyrannosaurus (as Dynamosaurus) to be displayed at British Natural History Museum



How on earth, assuming two populations were in contact and interbreeding, would 
you be able to tell an occasional or unusual hybrid from either a specimen from 
some point on a clinal intergrade or a simple variation of one stock that 
resembled the other in more ways than did the type of that stock, based on a 
single fossil?  I suspect it would be impossible.
 
Ronald Orenstein
1825 Shady Creek Court
Mississauga, ON L5L 3W2
Canada
ronorenstein.blogspot.com


----- Original Message -----
From: "Thomas R. Holtz, Jr." <tholtz@umd.edu>
To: wdm1949@hotmail.com
Cc: "bcreisler@gmail.com" <bcreisler@gmail.com>; DML <dinosaur@usc.edu>
Sent: Monday, September 2, 2013 7:50:17 AM
Subject: RE: First fossils of Tyrannosaurus (as Dynamosaurus) to be displayed 
at British Natural History Museum

Tyrannosaurus rex and Tarbosaurus bataar lived millions of years apart:
very latest Maastrichtian vs. early Maastrichtian. It is as likely as a
hybrid between modern humans and Sahelanthropus.

That said, had they encountered, quite likely that if you had a time
machine they COULD hybridize. Hybrids are not uncommon in nature. Hell,
despite what everyone is taught in BIOL101, *fertile* hybrids are actually
not uncommon in nature.

As to matching up specimens: the typological folks out there have to learn
to accept that you are obliged to eliminate the following prior to
asserting a new taxon (or in this case, a hybrid):
* Individual variation: no two individuals are identical
* Ontogenetic variation: no two growth stages are identical
* Sexual variation
* Geographic variation
* Stratigraphic variation
and the biggie after individual variation,
* Taphonomic variation

On Sun, September 1, 2013 2:50 pm, dale mcinnes wrote:
> On another note ..
>
> Does anyone still think about possible hybridization between T. rex
> and T.[Tarbosaurus] bataar ?!? I can't seem to remember but .. I seem
> to recall that at least one good specimen [? skull] did not match up
> within the variations ascibed to all other T. rex specimens.
>
> Perhaps Thomas could 

>
> I'll check out that other publication Thomas. Thanks.
>
>
> ----------------------------------------
>> Date: Sun, 1 Sep 2013 11:28:23 -0700
>> From: bcreisler@gmail.com
>> To: tholtz@umd.edu; dinosaur@usc.edu
>> Subject: Re: First fossils of Tyrannosaurus (as Dynamosaurus) to be
>> displayed at British Natural History Museum
>>
>> From: Ben Creisler
>> bcreisler@gmail.com
>>
>> Another slight inaccuracy to note: "it remains the only T. rex fossil
>> to exist outside of the United States." Of course, T. rex has been
>> found in Canada as well as the United States:
>>
>> http://okanagansisss.wordpress.com/2007/10/13/tyrannosaurus-rex-the-canadian-specimens/
>>
>>
>> To be fair, the specimens of Manospondylus (a single vertebra) and
>> "Ornithomimus" grandis (some foot bones) would likely not be
>> considered diagnostic by modern standards. The type specimen for
>> Dynamosaurus (minus the ankylosaur armor) would by itself be an
>> acceptable type specimen by modern standards.
>>
>> On Sun, Sep 1, 2013 at 11:11 AM, Thomas R. Holtz, Jr. <tholtz@umd.edu>
>> wrote:
>>> Dale beat me to it. Yes, both Cope's Manospondylus type and Marsh's
>>> Lancian specimens of Ornithomimus grandis are T. rex specimens that
>>> predate the Dynamosaurus type.
>>>
>>> As for the Mano quarry, check out:
>>> Breithaupt, B.H., E.H. Southwell & N.A. Matthews. 2008. Wyoming's
>>> <i>Dynamosaurus imperiosus</i> and other early discoveries of
>>> <i>Tyrannosaurus rex</i> in the Rocky Mountain West. in the Indiana
>>> Univ.
>>> Press Tyrannosaurus rex: the Tyrant King volume.
>>>
>>> On Sun, September 1, 2013 1:55 pm, dale mcinnes wrote:
>>>> So .. whatever happened to Manospondylus gigas ?!?
>>>>
>>>> I heard that the original quarry was relocated and that the large
>>>> centrum
>>>> taken by Brown was indeed part of that [old/ new] specimen. Any
>>>> updates
>>>> ?!?
>>>>
>>>>
>>>>> Date: Sun, 1 Sep 2013 09:18:29 -0700
>>>>> From: bcreisler@gmail.com
>>>>> To: dinosaur@usc.edu
>>>>> Subject: First fossils of Tyrannosaurus (as Dynamosaurus)
layed at British Natural History Museum
>>>>>
>>>>> From: Ben Creisler
>>>>> bcreisler@gmail.com
>>>>>
>>>>>
>>>>> A news story with video about the historically first specimen of
>>>>> Tyrannosaurus found and later sold to the British Natural History
>>>>> Museum. This was the specimen originally named Dynamosaurus
>>>>> imperiosus
>>>>> by Osborn.
>>>>>
>>>>>
>>>>> http://www.telegraph.co.uk/science/dinosaurs/10278054/How-Tyrannosaurus-rex-was-nearly-more-of-a-mouthful.html
>>>>
>>>
>>>
>>> Thomas R. Holtz, Jr.
>>> Email: tholtz@umd.edu Phone: 301-405-4084
>>> Office: Centreville 1216
>>> Senior Lecturer, Vertebrate Paleontology
>>> Dept. of Geology, University of Maryland
>>> http://www.geol.umd.edu/~tholtz/
>>> Fax: 301-314-9661
>>>
>>> Faculty Director, Science & Global Change Program, College Park
>>> Scholars
>>> http://www.geol.umd.edu/sgc
>>> Fax: 301-314-9843
>>>
>>> Mailing Address: Thomas R. Holtz, Jr.
>>> Department of Geology
>>> Building 237, Room 1117
>>> University of Maryland
>>> College Park, MD 20742 USA
>


Thomas R. Holtz, Jr.
Email: tholtz@umd.edu    Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:    Thomas R. Holtz, Jr.
            Department of Geology
            Building 237, Room 1117
            University of Maryland
            College Park, MD 20742 USA