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Re: four winged Archaeopteryx



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
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[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
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http://dml.cmnh.org/2006Oct/msg00006.htmlÂ;
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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
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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
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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
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CheersÂ
Â
TimÂ
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