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Dinosaurs and Beaks
When it comes to the issue of dinosaurs and beaks, apparently, it seems what
people are looking for is something that will correlate with a rhamphotheca
that can be found on skeletal remains. To my knowledge this has never been
found. (Maybe on mummified hadrosaurs, but I'm not sure.) Rugose areas and
smooth areas are both found for boney surfaces of the regions that we know have
a keratinous covering. When it comes to the pits that are seen in the
associated regions, we again see a variation that leaves us with little to no
answer. On both crocs that do not have a beak, and birds that do, such pits and
grooves can be found. Most of these pits and grooves hold branches of the
cranial nerves, along with associated blood vessels, and are sensory in nature.
Because they are sensory they are usually found in either animals that search
for food under water and use touch to help them do so, or in birds that have
extraordinarily thick beaks that seem to need extra sensors to feel a!
all. There are variations on this, but it means little to the issue. If the
keratinous region is made up of one fused mass or of smaller seperate scales,
we do not know. Looking for such elements does not really give us a clue. All
elements that are found in association with beaks show variations that remove
the possibility of using such elements as correlative factors.
Decay is uneven and usually favors the head first. To people that have not
dealt with finding dead birds and such and thus haven't taken note of the
variations seen, I recommend looking to the very popular forensic shows that,
to the shock and horror of many, often show pictures of dead people that were
discovered outside only after laying out for a few days. Many times the body
will still look basically normal to us but the head will be well on its way to
being skeletonized. I myself have found birds with no beaks left, yet they
still had much of the podotheca left and their unguals in place.
It does not matter if there are variations on this theme of which parts end up
decaying first. What is important is that there are variations. Also it is best
to remember that the animals in question, even if they did have a beak on the
premaxilla as Paul suggest, would have had a much smaller and thinner
rhamphotheca because the maxilla, not the premaxilla, was the dominant element
in that region with those species. When it comes to the rostrum in general in
those animals, they are built most delicately and would suffer more from decay
than the average neornithine.
The only answer we can hope to get to this question is to find a keratinous
covering in place on one of these animals. And even if we do find such a
covering, it should not imply, no matter what type is found, that we can then
use the evidence of one to suggest evidence for all.