Re: R: Late J Heterodontosaurs (was Re: Sereno's Prosauropoda)

[Dinogeorge@aol.com]

In a message dated 7/8/99 4:55:04 PM EST, amaris@tin.it writes:

<< For me the Heterodontosauridae is closer to Marginocephalia than to
 Euornithopoda, infact the three caniniform teeth are present only in the
 Marginocephalia (Protoceratopsidae and Pachycephalosauria) and not in
 Euornithopoda. >>

This is best apomorphy uniting H and M. But there are a few problems, such as 
premax extanding back to lacrimal in Heterodontosaurus and many (though not 
all) advanced ornithopods (probably appeared independently in 
Heterodontosaurus). Also a nice suite of primitive features common to H and 
M, but these aren't phylogenetically interesting.