bluesky22

Two More Soft-Tissue Fossils Pile on the Evidence Against Deep Time

https://crev.info/2018/12/two-soft-t...nce-deep-time/




Snip >>> Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.

https://www.nature.com/articles/s41586-018-0775-x






The second soft-tissue find this week concerns a special kind of bone found in egg-laying animals. It’s a highly porous bone found normally in birds and some dinosaurs, called medullary bone. It forms as a reserve of calcium when the female lays eggs. Phys.org reports from China’s Jehol strata that medullary bone has been found for the first time in enantiornithine birds, an extinct kind of Cretaceous bird.
In light of the currently available evidence, medullary bone might have been an entirely avian feature even in the Mesozoic. It evolved as a result of the thinned, hollow bones in birds, which lightened the skeleton for flight, as well as their increased egg size.
When medullary bone was reported in a T. rex dinosaur in 2005 by Mary Schweitzer (3 June 2005), scientists were shocked because it is a very fragile type of tissue that should not be preserved, and it only exists briefly during egg-laying. In that story, an NC State evolutionary spin doctor was well versed in how to spin this surprise for the public in order to preserve Darwin’s tyrannical reign: “We’re pleased to be able to provide a way for the public to see for themselves evidence that after millions of years, soft tissue can actually be preserved in dinosaur bone.”

Darwin’s Ministry of Truth at work. Shameful.