Cretaceous Echinodon (was Re: semilunate carpal)

["Tim Williams" <twilliams_alpha@hotmail.com>]

Mickey Mortimer wrote:

> > I have a Late Jurassic (late Tithonian) age for the Middle Purbeck beds
> > which yielded _Nuthetes_ (and _Echinodon_ as well).  Has this horizon 
> been
> > re-dated?
>
> I believe it has.  [snip] There are many members
> of the formation, the lowest of which (Caps Beds, Dirt Beds) may be
> Tithonian.  The others are Berriasian.  Nuthetes destructor was found in 
> the
> Cherty Freshwater Member, which is the sixth of fourteen members.  Thus, it
> was Berriasian.


Which means that _Echinodon_, also from the Cherty Freshwater Member, is 
also Berriasian.  If _Echinodon_ is included in the Heterodontosauridae 
(e.g. Sereno, 1997), this would extend the temporal range of this group 
forward by about 60-70 million years.  (Not including the undescribed Fruita 
"_Echinodon_" jaw from the Morrison.)


Tim



---------------------------------------------------------------------

Timothy J. Williams

USDA-ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163



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