Re: four winged Archaeopteryx

[mariusromanus@aol.com]

Tim, don't get your feathers ruffled... No need to get defensive. I  
mean no harm. Apparently I missed your post about Frey and Martill, 
1998. Blame it on my spam filter (it likes to filter the  DML).

This is from the 2003 paper... page 234, first paragraph... Body hair. 
Hints of the presence of fur in the form of fine pits and fibers in
the body area date from 1908 and were discovered on a specimen of 
_Rhamphorhynchus_ (Wanderer, 1908 [I don't have this paper so I didn't 
site it]), but it was Broili (1927a) who suggested these structures as 
being hair papillae or hairs matted together. These pits and fibres are 
exceptionally well preserved in a _Rhamphorhynchus_ specimen in the 
Leich collection, a former private collection which is now
accessible to the public in the Fossilium Tierpark Bochum (Germany). A 
fur-like body coverage in _Pterodactylus_ was first noted by Broili
(1938), while Frey & Martill (1998) described a mat of bristles along 
the neck of a specimen of _Pterodactylus kochi_. The same specimen
also preserves a uropatagium extending from the fifth metatarsal to the 
tip of the tail. Bristles along the neck are also seen in a specimen of 
_Grmanodactylus_ (Tischlinger 1998).

> > Thirdly, as I said previously, the Solnhofen theropod _Juravenator_  
preserves evidence of its integument, but does not show any feathers. 
However, _Juravenator_ does show tubercular epidermal impressions where 
related feathered coelurosaurs show feathers. Thus, it exhibits 
positive evidence for the absence of feathers.<<

I think you are making 2 very bad assumptions. One is that if any 
integument is preserved, then all aspects of the integument for the
animal are thereby represented. And second, if a region is feathered on 
one, and naked or scaled on another, this region is reflective of
the whole of the animal... I can't remember, are the tubercular 
epidermal impressions located everywhere on the _Juravenator_? Wait...
I remember... No, they aren't. So, how can anyone know for sure whether 
or not it had feathers? _Sinosauropteryx_ and _Microraptor_,
etc have been preserved with tubercular impressions and feathers. 
Having one obviously doesn't rule out the presence of the other. And
then there are the birds... Birds may have naked feet, or naked feet 
and ankles, or even naked knees and above, but how often does this
indicate a bird without any feathers at all? Anyway, hopefully you 
aren't saying that there is no possible way _Juravenator_ could have 
had feathers. This is probably a taphonomy-thing... more on that in a 
second.

Regardless, I was simply asking about the content of those papes and 
how they could relate to the animals of Solnhofen... The tropics, is
the tropics, regardless if it is tropical Germany or tropical South 
America. That's my point here. So about the hair/mammals and 
feathers/birds... Let me clarify... Your comment about "tropical 
climate" somehow meaning no insulatory integument on pterosaurs and
theropods in Solnhofen is where I see a logic disconnect. And your 
comment about birds not being found in Solnhofen has absolutely NOTHING 
to do with what I was saying... That was waaaaay off the mark. Maybe 
it's a problem of over-generalizing the animal kingdom... If logic 
follows, what you are saying about compsagnathids and pterosaurs living 
in tropical Germany (that being, they didn't have feathers or hair 
because of the weather) should mean that similarily-sized mammals and 
birds living in the tropics today should be predominately naked since 
they wouldn't need hair and fur for insulation in the tropics either... 
I purposely mentioned mammals so that someone wouldn't say a silly 
thing about birds having feathers since they fly or once flew. For 
those stuck on that wave-length, I answer with "tropical bats". And 
yes, there are mammals without coats of hair... but outside of 
primates, they are usually either very large, aquatic, or very small 
under-ground dwelllers. Also, most desert mammals and all desert birds, 
have the need for hair and feathers (besides flying)... and the HOT 
climate is one of the major reasons. I'm certain Greg Paul has talked 
about this... And one more thing, it looks like this discussion of the 
presence of integument on a fossil has to do a lot with taphonomy... 
I've talked about that quite a bit on the DML before... specifically 
what is and what is not preserved depending on circumstances of burial 
and decomp as observed with my own two eyes with many a dead bird found 
on the beach, in rivers, in lakes, in woods, and in fields... It's in 
the archives somewhere. And by the way, how many pterosaurs and 
theropods from Solnhofen do we have? I ask because it helps to have 
many specimens of one species just in case the one that you do have 
doesn't preserve everything.... Know what I mean?


Kris
Saurierlagen@gmail.com



-----Original Message-----
From: twilliams_alpha@hotmail.com
To: dinosaur@usc.edu
Sent: Sat, 7 Oct 2006 1:16 PM
Subject: Re: four winged Archaeopteryx

Kris (mariusromanus@aol.com) wrote:Â
Â
> Really???... Then what about said subject according to Frey, et al.!Â
Â
[refs snipped]Â
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Whooahhh!! Ease up there, pardner. First of all, I actually mentioned 
one of these papers (Frey and Martill, 1998), in a follow-up post...Â
Â
http://dml.cmnh.org/2006Oct/msg00006.htmlÂ;
Â
Secondly - and perhaps you can help me out here because I haven't 
actually read these papers and I assume you have - do any of these 
papers specifically mention that any Solnhofen pterosaurs have a full 
body covering of 'hair'. And are some of the specimens you're referring 
to actually from the Santana and Crato Formations in South America?Â
Â
Thirdly, as I said previously, the Solnhofen theropod _Juravenator_ 
preserves evidence of its integument, but does not show any feathers. 
However, _Juravenator_ does show tubercular epidermal impressions where 
related feathered coelurosaurs show feathers. Thus, it exhibits 
positive evidence for the absence of feathers.Â
Â
> And actually... by this logic... birds in the Amazon should be 
naked... >along with jungle mammals.Â
Â
Your 'logic' is flawed. No modern bird species (member of crown-group 
Aves) is found in the Solnhofen. It is true that no modern bird is 
secondarily featherless over its entire body (at least as adults), but 
this is irrelevant. However, based on phylogenetic bracketing, certain 
non-avian theropods appear to be secondarily featherless (at least as 
adults). Integumentary impressions are known for both basal and derived 
tyrannosaurs; the former have feathers, the latter do not. Then there's 
_Juravenator_ - if this Solnhofen taxon is a compsognathid then it is a 
member of a clade for which a feathery body covering is primitive.Â
Â
Many modern mammals are indeed effectively hairless. I'm not sure what 
point you were trying to make by citing mammals as an example.Â
Â
CheersÂ
Â
TimÂ
Â


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