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Re: Hongshanosaurus houi, new psittacosaur
In a message dated 7/2/03 1:04:12 PM EST, twilliams_alpha@hotmail.com writes:
<< If _Echinodon_ is a heterodontosaurid, then this taxon extends the range
of
this group into the Early Cretaceous. >>
Echinodon doesn't have the premaxillary tooth pattern shared by
heterodontosaurs and later marginocephalians (the premax teeth are lost in most
ceratopians
but one or two are still there in Protoceratops and some Psittacosaurus
species), so I'd place it in a sister group to the others.