Re: Avaceratops

[Dinogeorge@aol.com]

In a message dated 96-01-29 16:05:19 EST, Thomas_R_HOLTZ@umail.umd.edu (th81)
writes:

>If some paleontologists are correct, 'Avaceratops' and 'Monoclonius' are not
>taxa: they are growth stages in the life cycle of centrosaurines before they
>reach maturity (juvenile and subadult, respectively).  This will be
>discussed in a forthcoming article by Sampson, Ryan, and Tanke in the
>Zoological Journal of the Linnean Society.  The article title, by the way,
>is "Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia:
>Ceratopsidae): taxonomic and behavioural implications".
>
>

There's still a decent chance that _Avaceratops lammersi_ is a real species,
whose type specimen is a juvenile or subadult of a ceratopian as yet unknown
in adult form. But everything I've seen referred to _Monoclonius_ seems to be
indeterminate material referable to several species known from good adult
type specimens.