Re: Spinosaurus - the authors respond

[Dr Ronald Orenstein <ron.orenstein@rogers.com>]

This may be an ignorant question but: is it not true that semiaquatic animals 
are more likely, in the scheme of things, to fossilize than purely terrestrial 
ones - and if so, why is Spinosaurus so little known?  Might it have been 
genuinely rare in life?

Ronald Orenstein 
1825 Shady Creek Court
Mississauga, ON
Canada L5L 3W2
ronorenstein.blogspot.com

> On Sep 21, 2014, at 4:55 AM, "Thomas R. Holtz, Jr." <tholtz@umd.edu> wrote:
> 
>> On Sat, September 20, 2014 4:09 pm, dale mcinnes wrote:
>> How much spinosaur material is actually known from L. Cret. sediments in
> Africa
>> 
>> during/ after Campanian ? Is there enough time towards termination of
> the Mesozoic
>> 
>> to give rise to more highly derived spinosaurs ?
> 
> Very, very little is known of continental African faunas above the
> Cenomanian. Some new stuff is coming out soon, but not yet published.
> 
> But no spinosaurine material yet. And in fact none of the rare
> post-Cenomanian spinosaurid material anywhere is complete enough to say
> anything about how derived the critters were relative to Spinosaurus.
> 
> Face it: if we knew about such things, they would already be news!!
> 
> And of course there was enough time. Keep in mind, whales go from fully
> terrestrial animals to Basilosaurus in 15 million years or so.
> 
> 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