Re: Dinosaur Beaks

[MariusRomanus@aol.com]

Sorry about that truncation... It's the ailment I suffer from... It's called 
stupidity.

Jaime: > Fire away, < 

Nah..... Just a few facts and questions.... 

The basal bird *Confuciusornis* not only had a beak, but it also seemed to have 
had a truly deep beak because of the bony struts on the face. Even the back of 
the head in the postorbital region of this bird was thicker than most birds of 
the time. It is not too surprising that a bird that shows signs of such massive 
reinforcements of its skull would also have had a great thickness to its 
rhamphotheca. 

Burial matters...... The way in which an animal decays... How quick the burial. 
If there is a lot of sun. Moister contents... There are variables.   It is 
never a set pattern in animals that one item decays before another. Sun can dry 
an animal and kill off bacteria in some places only ten feet away from a place 
where the moisture would have caused a totally different affect. 

Point in fact.... What you are doing here is very similar to the argument that 
was given saying that since *Archaeopteryx* had feathers and *Compsognathus* 
did not, it was shown to be evidence that the ceolurosaur had naked skin. (Sad 
thing is, some still believe this.) The different environment of China vs 
Europe had noticeably differing results when it came to feather preservations, 
and there is little doubt that the feathered Chinese *Sinosauropteryx* is 
extremely closely related to the *Compsognathus* that was found next to the 
European *Archaeopteryx*. 

The facts are simple. We have been down this road before and many peoples faces 
were very, very red in the past. Think about it... How many hadrosaurs do you 
think had beaks? How many were actually found with them? Your main premise is 
if the ungual sheaths are found on the fossil this can be correlated to mean 
whether or not the animal had a beak... "Had claws but we cannot see a beak. 
Must mean there was no beak"... The facts are that the scales on reptiles are 
not much different in toughness than a beak. It is just that scales are really 
a broken up pattern of keratinous plates that are surrounded more by other 
tissues like skin. It is really this skin that speeds up decay. The greater the 
amount of skin and other soft tissues in a region, the greater the decay in a 
moist environment. 

In animals like *Archaeopteryx*, the premaxilla is still small as in other 
theropods of its time. The dentary is also rather delicate. This region would 
have had little in the chance of preservation with all of the soft tissue 
around it to start the bacteria going. The fact is, there is nothing about the 
dentary and premaxilla in these animals that denies a rhamphotheca. Yes... 
Maybe it did not have a beak, but the facts are that scales, like found on the 
feet of some of the animals mentioned in this discussion, have not been found 
on the face, showing that either it had no keratinous covering at all out side 
of bare skin, or decay is uneven in the decay process when it comes to facial 
tissue. We all know skulls in general seem to suffer from disappearing more 
than any other region of the skeleton outside of the loss of distal caudal 
vertebrae and phalanges. The head, like the gut, explodes with bacteria as soon 
as an animal dies. The skull is usually the one that shows the !
mo!
st signs of this in the fossil record. This may be the reason why skulls are so 
rare in the first place (or at least a major part of it). 

Remember what the word empirical means??? What is it telling you when you find 
a bird skeleton that still has a podotheca but no rhamphotheca??? Name one 
element in the premaxilla and dentary of the animals that Aspidel mentioned 
that are not variations of what we see in animals with beaks. 

Answers to those questions should clear all of this up. 

Kris