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Re: four winged Archaeopteryx



Kris (mariusromanus@aol.com) wrote:

Really???... Then what about said subject according to Frey, et al.!

[refs snipped]

Whooahhh!! Ease up there, pardner. First of all, I actually mentioned one of these papers (Frey and Martill, 1998), in a follow-up post...

http://dml.cmnh.org/2006Oct/msg00006.html

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?

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.

And actually... by this logic... birds in the Amazon should be naked... along with jungle mammals.

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.


Many modern mammals are indeed effectively hairless. I'm not sure what point you were trying to make by citing mammals as an example.

Cheers

Tim