[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Coelophysis *feathers*???



> >No, no. Some people think that all dinosaurs are decended from birds, and
I
> >feel this is wrong. I feel that some "theropods" were probably descended
> >>from "birds" (e.g. oviraptosaurs), but most were probably not. I just
feel
> >that "feathers" might be basal, and birds adapted these "feathers" into
> >true feathers.
>
> Don't ask me why, but I also feel that the Oviraptorosauria are
> avian....just a gnawing suspicion. The palate in 'em looks pretty birdy to
> me, and then you have the pygostyle of Nomingia (thanks Mickey for the
> details on N.!!!!)....which ?might be homologous to a primitive avian
> pygostyle? But I figure it's more likely that they are simply off-shoots
> near the base of avialae.

Well, I have thought so in my paper, and HP Mickey Mortimer has kindly sent
me a figure of the tail of *Caudipteryx* that looks a lot like not having a
pygostyle. No tail ends of alvarezsaurids and *Avimimus* are known... but
those of a few oviraptorids are and have none, too. The palate, however...
and the short, mobile tail...

> >Not to put too much feeling into this, but I think this person is
entirely
> >wrong. How can time not count? You can't be older than your ancestors?
> >People say that birds descended from dromeosaurs...but there are 0
> >dromeosaurs known from before the late Jurassic! Time is very important.

Time is theoretically very important, but practically we have a fossil
record with yawning gapes. |-O

> I'm not too sure about the relationship of dromaeosaurs to troodontids
after
> the description of Microraptor zhaoianus, but they seem to be fairly close
> to eachother.

Don't think so. Troodontids look a lot like *Pelicanimimus*.
(Bullatosauria!)

> So, if we have Borogovia

*Koparion* from the Late Jurassic of Utah. *Borogovia* is from the Late
Cretaceous of Mongolia.

> and Palaeopteryx

Whatever that is.

> in the LJ, the split
> with dromaeosaurs must have been earlier.

True.

> I've also heard that dromaeosaur
> teeth have been found from the EJ of Antarctica (just a rumor I guess, but
> it could be more).

There seem to be plenty of LJ dromaeosaur teeth from Guimarota/Portugal,
there are a few bones from the Morrison described in 1989, there are MJ
dromaeosaur teeth from England and Russia and the mentioned EJ ones from
Antarctica. HP Mickey Mortimer was so kind as to send me the refs, but
probably offlist, in which case I probably can't dig them up (harddisk crash
in the meantime). There are also MJ troodontid teeth from England and LJ
ornithomimosaurian teeth from the USA as well as an English Kimmeridgian
(mid-LJ) ornithomimosaur finger!

> >I am waiting for this paper to come through on interlibrary loan. Then I
> >will be able to make a more informed descision.
>
> Got a ref? I'd like to take a look too.

Cool!

> >And I fully belive that there were no feathers in ornithopods, sauropods
> >and >fully grown< _C. sasteri_ and _C. nasicornis_ specimens.
>
> I'm a believer in parsimony. If there is no good reason to believe in it,
> and no evidence for it, then it probably didn't exist. Not that i'm "stuck
> in my ways" or anything, but all it is (for now) is a fanciful idea with
no
> scientific backing. But so were Greg Paul's feathered dino portraits. At
> least now we have some clue to feather distribution within dinosaurs. BTW,
> is there ANY evidence for non-coelurosaur tetanuran scutes?

No AFAIK.

> >I am hoping that soon we
> >will find an early Jurassic/late Triassic deposit much like the ones now
> >being explored in China. This will answer many questions (hopefully!)
about
> >bird evolution.

:-9 :-9 :-9

> Hmmmm, how complex is a strand of hair? As far as I know, it's just an
> elongated scale/scute with a follicle. A structure that simple could
evolve
> convergently among many taxa, so is of doubtful use in figuring out if we
> have fluffed-up basal dinos.

We should find out what pterosaur hairs are, because mammalian hairs are not
scales, but derived from strange cogs between the scales, AFAIK. (No ref,
damned alzheimer.)