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Re: Tyrannosaurs with leathery skin, etc.
With respect to Sinosauropteryx-
The manus is tridactyl from everything I've heard/seen, but
Sinraptor's fourth metacarpal wasn't associated with the manus.
On the one hand, it seems strange an allosaur should have MC IV,
on the other, I don't really know what else that bone would be. It could be
that there is some homoplasy there- on yet the other hand, perhaps three
digits is an Allosaurus-Sinosauropteryx synapomorphy.
Regarding tooth serrations, the new AMNH troodont has needlelike
teeth completely devoid of serrations. Tooth characters just don't sit well
with me, teeth seem to be rapidly evolving structures. My guess is that
they might be useful for species-level systematics of theropods but not for
family-level problems like this one. I really don't know that
Sinosauropteryx' arms can be compared to Compsognathus. First of all, the
radius in the type is missing and its imprint may not even give an accurate
picture of its size; second the digits are long and slender, not at all
like the stumpy and powerful thing you see on the thumb of Sinosauropteryx.
With respect to the tail, maybe I'm wrong on this one- it looks to me like
there are ridgelike transverse processes out on the distal caudals;
certainly there are still large neural spines and this isn't a point about
it's affinity or lack thereof to Compsognathus, merely that I doubt it is
particularly close to birds.
Also, if the comments on the ilium and ischium refer to GMV 2124,
which is the larger of the two theropods on display in the National
Geographic exhibit and splashed over two pages of their feathered dinosaur
issue, there are questions about whether this is, in fact, a
Sinosauropteryx, so it can't really be brought into the debate. The second
animal published by Chen et al. in Nature does appear to be
Sinosauropteryx, judging by its first digit.
>They may not have been illustrated, but they are specifically referred to.
>If we could only trust what was illustrated, those of us unable to examine
>specimens would have a lot more ?'s in our matrices.
I think we'd all be better off with more ?'s in our matrices. Too
often people take for granted the opinions of others, poor illustrations,
and their own misinterpretations of fossils. Before anyone thinks that's me
being insulting, I'd like to volunteer myself as one of those guilty of All
Of The Above. Which is why I try to avoid coding fossils where the state is
ambiguous, or using vague characters. From time to time I like to go on a
rampage and axe whole characters out of the matrix because I just don't
think they can be coded objectively enough, or I don't know enough about
them to evaluate them objectively, or I haven't seen enough of the stuff.
When a lot of these relationships are hinging on just one or two ones and
zeroes- which I think they are for things like Compsognathus and
Sinosauropteryx where so much vital data is missing- then it's extremely
important not to introduce misleading data. I'd rather come up with nothing
at all than a bad answer. I don't know. Maybe I'm wrong. I guess I just
feel it's really important to be honest with one's self about when you're
ignorant. One can't learn the answer to something if you think you've
already got the answer. I'm just not sure we do know anything for sure
about these things.
With regard to Nick P's obturator character ("just attached" vs.
"confluent" or however you'd put it), I think that is a cool character.
>From what I've seen of the Compsognathus cast, compsognathus is definitely
more coelurosaurian in this respect. With respect to the variability of the
backwards inclination of the ischia- I really wonder if maybe there
couldn't be some sexual dimorphism in some of these creatures, in the hips.
I saw something pretty cool the other day- a mosasaur called
"Globicidens" or something like that. It had these absolutely massive jaws-
no, I mean really heavy- and teeth like one-inch ball-bearings, sometimes
with a tiny nipple in the middle. Yes, like ball bearings. No, I'm not
exaggerating. No, it wasn't a placodont. I mean, what in the ***heck***?
It's like a bad psychotic hallucinatory episode for an abalone or
something, the thing does not look like a molluscivore, it looks like a
satire of a molluscivore.
Of course, isn't the mesozoic when you get those super-heavy-duty