[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

BEAKS, CHEEKS AND CRESTED ARCHAEOPT..



Just can't get enough of those therizinosaurs! I am presently trying (*trying*)
to clear up a few details for a forthcoming restoration of a therizinosaur, and
I'd appreciate some help with bits and pieces.
 
BEAKS 

Vascular foramina are visible on the rostral-most edges of _Erlikosaurus_'s
skull. Are these definite evidence that horny beaks were present here? Are such
foramina good evidence for beaks, if so are they present in any bird skulls? I
note that tyrannosaurs, and other dinosaurs, possess foramina which are
generally considered evidence for lips. Does this invalidate consideration of
evidence for beaks from foramina? 
 
Having examined available therizinosaur restorations, beaks are evident only
at the ends of the jaws. Supposing (that was just for you George) that
therizinosaurs _are_ theropods, and furthermore derived coelurosaurs, is it not
likely that they possessed a good beak that went all the way up to the end of
the antorbital fenestra, as it is often shown doing in oviraptorosaurs, and as
it does in birds...? Or what?
 
CHEEKS
 
The _Erlikosaurus_ tooth rows are somewhat inset from the jaw margins. Cheeks
were therefore present. I recall reading something that disputed this
interpretation, but I can't remember where it was. And if therizinosaurs _did_
have cheeks, is this weird for a theropod or what? 
 
I would appreciate whatever feedback can be mustered on these subjects. Please
help...
 
ARCHAEOPTERYX CREST
 
In PDOTW, Greg makes mention of a head-crest that was apparently present in an
early drawing of an _Archaeopteryx_ specimen (possibly the Berlin specimen?),
but has since been destroyed by preparation (the head crest, not the drawing).
I recently saw an old drawing of the Berlin specimen that seemed to show this,
and am presently trying to find exactly where it was. Check out the drawing of
the Berlin specimen in Psihoyos. Does that have a crest? (Can't remember right
now).
 
Whether or not _A_ was a dweller of the Solenhofen islands, and if it therefore
lived a 'crude shorebird' existence, is a hypothesis that can be tested by the
taphonomy of extant birds. This is a project I will shortly be engaged in.

"Come with me if you want to live"  - *NOT* Arnold
 
DARREN NAISH
> 
> --MAA05501.807794427/alder.soton.ac.uk--
> 
>