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RE: More on the baby Triceratops

Whoa! The evidence for Maisaura is weak. It was based on a lot of
assumptions as I addressed in Eggs, Nests and Baby Dinosaurs. It is weak
in the majority of dinosaurs. There has even be a question raised about
Psittacosaurus - namely, where is the skeleton associated with the adult
skull? Why don't other hatchling groups show an adult present (another
undescribed Psittacosaurus group; Protoceratops hatchling clutches
(several now), etc.)  

Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/
Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
Phone: 303-370-6392
Fax: 303-331-6492

for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of T. Michael Keesey
Sent: Wednesday, March 08, 2006 9:53 AM
To: dinosaur@usc.edu
Subject: Re: More on the baby Triceratops

On 3/8/06, Ken.Carpenter@dmns.org <Ken.Carpenter@dmns.org> wrote:
> But phyletic bracketing also includes the bowler bird, which does not 
> have parental care after hatching.

Is that a megapodiid?

As I understand it, that just illustrates that parental care can be
lost, but isn't relative to the PB in this case. Off the top of my head,
outgroups to _Triceratops_ for which the state is known are
_Psittacosaurus_ (present; I completely forgot about this when writing
my earlier post), then _Maiasaura_ (present), then _Aves_/_Neornithes_
(present, lost in megapodiid galliforms), then _Crocodylia_ (present).

Of course, I don't know how you could ever prove that a fossil animal
*didn't* care for its young, so that could mess with the bracket, since
it can only show positives for fossil taxa. There is that possible
creche of young ankylosaurs (can't recall which species at the moment),
but, IIRC, they weren't all that young, and, anyway, there could have
been a guardian adult nearby who survived or otherwise was not
preserved--who knows?
Mike Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com