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Re: Hump-backed dinosaur from Spain



Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:

> The issue here (well, one of the issues), is that the simplistic
> typological binary thinking that some seem to use (either an animal is
> fully feathered or it is totally scaly) is at odds with the living 
> world. The origin of the capability of producing feathers does not
> mean that the whole critter is totally feathered.

Exactly.  Unfortunately, these kind of all-or-nothing dichotomies often 
dominate scientific discussions.  

Another false dichotomy: The "ground-up" versus "trees-down" origin of avian 
flight.  The living world tells us that many birds spend time on the ground and 
in trees - so why not their ancestors?


> I suspect that we are going to find that individual non-avialian
> theropod taxa (and even ontogenetic stages of the same taxon) are
> going to show a mosaic of scales and feathers, and that these may even
> come and go in different sectors of the body.

I'd go even further and say that the coverage of feathers might even have been 
seasonal in some non-avialan theropod lineages.  If associated with insulation, 
parts of the plumage could have been shed in the spring.  If associated with 
display, it could be shed after the mating season.


Michael Mortimer <mickey_mortimer111@msn.com> wrote:

> Both us and Cau have also made the connection between
> Concavenator and Becklespinax.  I'm really amazed that
> taxon wasn't mentioned by Ortega et al., since it's quite
> well known and has the same distinctive dorsal morphology. 


I still maintain the correct name of _Becklespinax_ is actually _Altispinax_.  
Although Huene was totally befuddled with respect to the type species, it is 
clear that in 1932 he explicitly attached the name _Altispinax_ to the 
distinctive tall-spined vertebrae.  So the name should be _Altispinax 
altispinax_.


Cheers

Tim