Re: dino skin

[Adam Yates <zooamy@zoo.latrobe.edu.au>]

> 
> >> There are SEM photos of a smallish ?maniraptoran specimen found in a
> >> calcareous concretion from the Santana Formation (which produces all those
> >> nice pterosaurs). Sorry, no feathers, scales, or ossicles--and they would
> >> have been preserved had they been present. The material includes a pelvis,
> >> hind limbs, and some caudal vertebrae in addition to the soft tissue.
> Blood
> >> vessels, muscle fibers, other good stuff.
> >> 
> >This particular species may have had feathers only on the torso, if they
> were
> >present. 

Even if the legs, hips and tail bore feathers, they would not have 
necessarily been preserved in this specimen. Internal soft tissues are 
sometimes preserved in the Santana Formation by phosphate replacement. A 
seir of experiments by Dr. Briggs of Bristol University has shown that 
phosphatisation of soft tissue requires an highly acidic environment (as 
well as a supply of phosphate ions), such as occurs inside a decaying 
carcass. It is unlikely that the conditions were suitable outside the 
carcass, where the feathers would have been (if they were present at 
all). I note also that the pterosaur soft tissue from the Santana shows 
none of the hair-like structures that are present in other well 
preserved pterosaurs.

Adam Yates