Re: The timing of stegosaur extinction

[Tim Donovan <uwrk2@yahoo.com>]

> > Lucas and Estep (1998) say "key taxa of
> biochronological value" for
> > Tsagantsabian age are Prodeinodon, Asiatosaurus,
> Psittacosaurus and
> > Dsungaripterus.  But both Prodeinodon and
> Asiatosaurus are currently
> > indeterminate, so no remains besides the Huhteeg
> Svita holotypes can be
> > referred to them.  Psittacosaurus is said to also
> be in the younger
> > Khukhtekian sediments, 
> 

 Dsungaripterus is also known from the Wuerhosaurus
bearing upper Tugulu group. Those beds are considered
the equivalent of Tsagantsabian beds in Mongolia based
on fossils. K-Ar dating etc indicates a
Berriasian-Valanginian age for the Mongolian beds. 
Some of the Tsagantsabian taxa may have survived into
the late early Cretaceous but not stegosaurs,
apparently.
 IIRC K. Carpenter mentioned a new, Aptian age for the
Yellow Cat onlist.


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