[Taxacom] Sinosauropteryx tail colors

Kenneth Kinman kennethkinman at webtv.net
Wed Feb 3 22:36:02 CST 2010

Dear All,
     While I am on the subject of protobird origins and phylogeny, I
might as well also delve into the recent discovery of a bicolored tail
in Sinosauropteryx.  It provides even more evidence for my hypothesis
that protofeathers initially evolved as a distraction display on the
tail which could attract predators to a more expendable tail (rather
than the far less expendable body and head).  It might not have been
quite as "detachable" as some living lizard tails which use this
strategy, but it might have been successful enough to have saved enough
Sinosauropteryx and related forms to have also adopted the same strategy
back in the Mesozoic.
      Actually this strategy was perhaps not restricted to theropod
dinosaurs, since the bristle-tailed psittacosaur dinosaur discovered
several years ago might have indicated a similar strategy in another
dinosaur group.  My hypothesis has been that an early dinosaur group
evolved protofeathers on the tail which served just such a purpose, and
only later did the protofeathers expand to the hind legs and body and
become exapted for other purposes (such as thermoregulation perhaps to
better incubating their eggs). They then spread over the entire body for
increased thermoregulation and only later for gliding and then flight.
Archaeopteryx might represent the strongly gliding stage, but still
short of what future birds would develop into "true" powered flight
(although so gradual that defining "true" powered flight along such an
evoutionary continuum would probably largely be an exercise in futility
as more intermediate forms are discovered).  Powered flight was a
gradual process, not eastily defined, and far less so among fossil
forms.  What preceded aerodynamic feathers (for gliding and powered
flight) is obviously even more difficult to document.  Those early
stages happened mostly in the early Jurassic where fossils are scarce
and very poorly preserved.  Anyway, here is more about the
Sinosauropteryx with a bicolored tail:


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