Feathers

["Antoni Lacasa" <fossils@redestb.es>]

Hi all, 
At first, please to excuse my bad english language.

Paul Davis wrote:

> The Solnhofen Compsognathus has eggs preserved [...] about 17 if
> memory serves me right

I have a good replica of Compsognathus longipes, and I am unable to find any 
trace 
of the eggs or eggshell...Please, can you indicate me where you have see this 
17 eggs? In its stomach is Bavarisaurus...but eggs?

> The Berlin specimen shows some traces in the neck region which my
> well be body contour feathers but I have yet to convince myself

Also, I have a good replica of Archy from Berlin specimen, and I can see 
contour 
impressions featherlike surrounding the body: Impressions along its 
tibiotarsus, 
on dorsal blackbone...indeed, the structure of this impressions is not the 
typical 
feather of the wings, right, but are impressions of the soft feathers 
(=contour).

To all friends,
And now a silliness...
In the early bird evolution: If a fossil skeleton have not evidence of the 
feathers but its bone structures have a primitive condition near to old 
*birds*...Can we indentify it as bird or dino..?(for instance Compsognathus)

My idea (attention, only idea, not evidence!) about the beginning of feathers 
is:
If the hypothesis of a beginning to thermal retention based on feather 
insulation 
is accepted in(parcial or not) endogenotermic, fast and agile protoavians, we 
must 
consider this adaptation as relating to those causes which would favour body 
heat 
dissipation.
This presumed heat loss must have been linked to an important biological 
function, 
as if not, the appearance of feathers would not have prospered. It is possible 
that this function might have, among other possibilities, concerned obtaining 
food, its source and the feeding methods used.
Among the divers biotopes which presented a varied fauna there were lakes, 
pools 
and marshes, where there could have been no lack of larvae, aquatic insects, 
molluscs, crustaceans (remember Eoalulavis hoyasi), fish and amphibians.
We can imagine a small group of protoavian theropods beginning predatory 
incoursions into the water.Continuous invasions of the water in search of food, 
would tend to reduce corporal temperature, encouraging insulatin, waterproof 
feather covering, devired from special type of scale, to preserve the animal's 
thermal balance...
With regard to this it is also interesting to observe a significant porportion 
of 
Early Cretaceous fossil birds are related to aquatic environments...

Some references:*The evolution of Feathers*  Jan Dyck. Zoologica Scripta.1985
*Hypothetical begginnings of feathers in continental aquatic 
palaeoenvironments"*
A.Lacasa. Terra Nova 1993.

Kinds regards.

Toni fossils.