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Re: Thoughts on the new Czerkas book (long)



> Right, he puts Maniraptorians right smake dab into aves and therefore, if
you follow the logic, not in theropods anymore. But if you keep theropods
into birds ala BCF (or actually the other way around) then this doesn't mean
 anything, they're all birds.<
I don't see how this precludes Aves from being a clade within the
Dinosauria...if so much argument/discussion on this list revolves around the
dinosaurian origin of birds, then how does it matter if one particularly
birdy clade of  non-avian theropods falls within Aves...maybe because I
don't study this area much (at all, really), I'm missing something, but I
just don't see how this jeopardizes the dinosaurian origin of birds...GSP
argues something similar, right, in regards to flightlessness, and yet still
considers "birds" to be dinosaurs...what's different here?
Peace,
Rob

Student of Geology
400 E. McConnell Drive #11
Northern Arizona University
Flagstaff, Az. 86001
http://dinodomain.com
http://www.cafepress.com/robsdinos
AIM: TarryAGoat


>
> >>This does not agree with Chatterjee, and requires evolutionary changes
> Czerkas does not adopt. Chatterjee, for instance, sees and presents
> dromaeosaurs as being well-nested maniraptoran theropods, not basal
> dinosaurs.<<
>
> Semantics with Czerkas's point of view.
>
>
> <Well, considering Norell only had a few hours to look at the specimen and
> Czerkas et al had weeks, I'd go with Czerkas et al. (not to mention I've
> seen the specimen myself :) ). They had long, typical flight feathers on
> the 'wings'.>
>
>   Actually, according to Mark, he had this particular specimen for quite a
> while in his office alone. For some weeks, I was to imagine. Nothing
> dismisses his time with it to validate Czerkas'. The latter does have a
> cast in his own museum, though, and likely one of each specimen he has
> described as well as the "Archaeoraptor" composite before it was broken
> up.<<
>
> Hmmm, something is odd here. Czerkas told me he had the specimen and it
> wasn't at the AMNH (as I said, I know he had the specimen because I saw
it,
> not a cast). Could it have been at the AMNH first?
>
> <But, you can trace the feathers from the wing to the tibia, if you follow
> them. But figure 1 shows that you can see which 'wing' the feathers are
> coming from.>
>
>   I haven't seen this,<<
>
> I have, the actual specimen, and saw how the feathers.
>
> >>so this is cautionarily drawn: how does one support
> the continuation, rather than double-layering of integument, on both tibia
> and arm? As I was to understand, the arm was examined for integument and
> was found, but the rear structures to diverge from the hips instead. From
> what I have seen, unlike the *Psittacosaurus* of Xu & Wang and Mayr et
> al., integument does not progress _over_ the bone preserved in this
> specimen. (For those that do not know, the "spiny" psittacosaur that Mayr
> recently described has pebbly skin that progresses over the metatarsals as
> well, giving them a continuous "speckly" or "spotty" appearance.>>
>
> The feathers are from the opposite wing from the way the specimen is
laying
> or, it's laying on its wing, the leg is sitting over the feathers so the
> feathers are on the other side of the leg, so you wont' see it
continually.
>
> <Ok, so who as done cladistically what they are saying hasn't been done?>
>
> >>The logic holds that a sequence cannot be "known", only postulated.
> Knowing who lost flight rather than seeing a flight-related condition or
> just long feathery arms makes nothing towards a sequence, just are. One
> then takes this in context to something else and proposes a sequence.
> That's all. This is what Tom was talking about.<<
>
> So, it can't be done? So, why bring up the point?
>
> <Show me the cladigram that does do that, shows how Dromaeosaurs are
> secondarily flightless.>
>
> >>Nothing can, just theory. Same as no cladogram can show dromies could
> fly. They either could, or did not....<<
>
> Then don't argue about it.
>
> <Since so many are fighting against it I'd like to see them show that they
> were secondarily flightless.>
>
> >>Please. Different opinions on origins does not mean fighting. Not even a
> staunch position. It's those that curse and scream that the "other guys"
> are idiots that fight, they refuse to listen or understand the
> "opposition." Science is about ideas, not people.<<
>
> Right, how long have you been at this and how long have I? How much
> 'fighting' against things have you seen and how much have I? Do you know
how
> many people have fought against BCF? Do you know how many paleontologist
> have blown me off??? I don't have a degree, therefore I don't know what
I'm
> talking about. BUT some of what I say has been proven by others. Please, I
> know of where I speak on this.
>
> <Per se? In that statement you just said that you don't believe it. Your
> fighting against it, just like the majority of people. Get over it, they
> flew..>
>
> >They? There are more than just *Cryptovolans*? Because all the others I
> know of (meaning, described) do not have the shoulders or arms (or
> integument) to _fly_. This fellow's the only one _now_.<<
>
> Some Dromaeosaurs, that's the they.
>
> <We only  know how MODERN birds fly. Which muscles, etc., we don't know
> how these kind of animals could fly. We HAVE to stop thinking of modern
> animals and look at how things could have been. This is a dogma of modern
> science...>
>
> >>  A la Dickson, rather? Helium inflation? Sauropods floated a la
balloons?
> Sorry, humor here.<<
>
> Bad at that.
>
> * Because I have been analyzing flight mechanics and
> evolution for a few years and the adaptations of arboreality, and those
> that fly without special means (us), or beyond special limbs (insects) fly
> by some very specialized and specific muscles. Those that had broad
> sternae and flexed coracoids with raised glenoids have osteological
> correllates that show _which_ muscles were used. There there is a degree
> of unknowingness involved still shows that there can be differences, but
> the bones show us that these would be very, very limited.<<
> *
> * Yet, some of the bone structure, furcula, sternum, are like some early
> 'birds' and they flew.
> *
> * >> Besides, what does Czerkas think of troodontids? *Sinovenator*?
> Oviraptorosaurs and
> segnosaurs?<<
> *
> * Ask him.
> *
> * >> You keep getting birdy closer to these animals, until dromies
> differ by just one or two features from their neighbors. *Ornitholestes*,
> even? Czerkas has a bit to go to his theory, I think.
>
>   Cheers,
>
> =====
> Jaime A. Headden
>
>   Little steps are often the hardest to take.  We are too used to making
> leaps in the face of adversity, that a simple skip is so hard to do.  We
> should all learn to walk soft, walk small, see the world around us rather
> than zoom by it.
>
> Tracy L. Ford
> P. O. Box 1171
> Poway Ca  92074
>
>
>
>