Re: NEW CERATOP{S}IANS & ANKYLOSAURIANS

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>ASINIOSAURUS
>
>or whatever it's called. This new ceratopian was named together with another
>one which has the specific name 'horneri'. Asiniosaurus might be the new name
>given to what was previously named as a species of Styracosaurus. The animal
>had an odd, decurved nose horn and only ?four marginals round its frill. Then
>again, it could be something completely different ... in that case what's the
>new name given to the 'Styracosaurus'? (It was just fine as a Styracosaurus
>species, dinosaur genera are always being oversplit!)

Actually, you are confusing two new ceratopsians (sorry, etymologically
correct or not, I will *never* use ceratopian!).  Einiosaurus
procurvicornis is the one with the downcurved horn, Achelousaurus horneri
is the one named after Horner.  These seem to form a phylogenetic series
Einiosaurus + (Achelousaurus + Pachyrhinosaurus) within the Centrosaurinae.
Einiosaurus was once *unofficially* called Styracosaurus makeli, but as
far as I know, that name was never formally proposed.  Styracosaurus
albertensis remains Styracosaurus.

If we wish to keep monophyletic genera, the appropriate options would be to
rename Einiosaurus & Achelousaurus Pachyrhinosaurus procurvicornis and
Pachyrhinosaurus makeli - naming any of them Styracosaurus would
necessitate a paraphyletic Styracosaurus or turn "Styracosaurus" into
something that already has a perfectly good name - Centrosaurinae.

>NEW ANKYLOSAURS AND THEIR SHORT LEGS
>
>OK, OK.... yes, ankylosaurs (particularly some nodosaurids) have short arms -
> but not legs! Mymoorapelta maysi is the name given to Kirkland's new Morrison
>ankylosaur. It has short arms. An exciting new possibilty (currently being
>written up by ?Carpenter and others) is that 'nodosaurids' with big, lateral
>tail spikes belong to a different family - the Polacanthidae. This was
>previously diagnosed in the 19th century but since been sunk into Nodosauridae.
>It would include Mymoorapelta, Polacanthus and ?Sauropelta...

Can anyone actually find the original proposal for "Polacanthidae"?  When I
last talked to Jim, and to George Olshevsky, both agreed that the name was
floating around out there, but neither could find the original citation.

And actually, where does Acanthopholis (and the Acanthopholidae) belong in
the newer ankylosaurian phylogenies?  Comments from anky workers most
appreciated.

I think Sauropelta seems to be more similar to more typical Late K
Nodosauridae, and so probably will remain a nodosaurid.

>I understand that Kirkland has just discovered another new Morrison ankylosaur,
>which has now been named. Can anyone help?

I don't know about another Morrison one, but Kirkland has a "polacanthid"
from the Cedar Mountain (Aptian-Albian) which is going to be named
Gastonia.  Additionally, we now recognize that the ankylosaurian
"Hoplitosaurus" marshi from North American formations equivalent in age to
the upper Wealden is a second species of Polacanthus, P. marshi.

                                
Thomas R. Holtz, Jr.                                   
tholtz@geochange.er.usgs.gov
Vertebrate Paleontologist in Exile                  Phone:      703-648-5280
U.S. Geological Survey                                FAX:      703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092
U.S.A.