Re: Revising Hou et al, 96 (woo-o-o-o-o-o-o doggy!)

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Jaime Headden wrote-

> <No, I said Rahonavis has the "pes construction (an apparent troodontid +
> dromaeosaurid synapomorphy, along with pedal digit II features)" that you
> said was evidence for placing Microraptor in the Deinonychosauria.>
>
>   I was refering to the caudal flanges on the metatarsus, which was my
> very previous paragraph. What were _you_ thinking of (not to be taken
> insultingly -- change the accent on the next word and this could be
> fightin' words...)?

You keep changing what you say you're writing about.  Following this from
the beginning, we see that-
1. I listed the elongate prezygopophyses and chevrons of Sinornithosaurus as
one of the characters Xu et al. (1999) used to assign it to the
Deinonychosauria, but said this was also found in Microraptor, "which is
even more bird-like (but still thought to be a deinonychosaur by many)."
2.  You replied by saying yes Microraptor is thought by many to be a
deinonychosaur, and "for many other reasons, including the pes construction
(an apparent troodontid + dromaeosaurid synapomorphy, along with pedal digit
II features)."
3. I replied that these "deinonychosaurian" pedal features are "also found
in Rahonavis, a probable avialan."
4.  Now, you become confused.  You cite my quote above as being in regards
to "elongated rostral chevron processes", which it wasn't.  After this you
reply that they are present in Rahonavis "Too a much smaller degree."
Obviously, Rahonavis does not have the deinonychosaur-type tail with
elongate chevrons and prezygopophyses, so you're right that they are
developed "to a much smaller degree", but I never claimed ANYTHING regarding
Rahonavis' tail.  I pointed out that I wasn't talking about the tail, and
that Rahonavis has a more specialized sickle claw than Microraptor, so the
pedal characters are not dveloped in Rahonavis "to a much smaller degree".
5. Finally, you say you were talking about the caudal metatarsal flanges,
directing me to you "very previous paragraph", when in actuality you did not
bring those up until the very end of your post, long after this whole
confusing set of replies.  So, let's get everything settled-
A. Elongate caudal prezygopophyses and chevrons are a possible
deinonychosaur character of Sinornithosaurus, assuming Microraptor is also a
deinonychosaur.  However, if (as in my phylogeny) microraptor is an avialan,
they tell us little about Sinornithosaurus.  Rahonavis and Archaeopteryx are
agreed to lack this character.
B. Rahonavis has a more strongly developed sickle claw than Microraptor, so
sickle claw characters are very poor evidence for deinonychosaurian
affinities in the latter taxon or Sinornithosaurus.
C. Caudal metatarsal flanges are found in Sinornithosaurus and Microraptor,
but also in Archaeopteryx (Paul, 2002) and possibly Rahonavis.  These are
thus also poor indicators of deinonychosaurian affinity.
Whew!  Glad we got that cleared up....

> As for ornithomimids (and the other taxa), I was measuring
> the subnarial hieght versus length, not the total premax height, which may
> be functionally deformed due to external narial shape and size, and I do
> not think this is a valid reason to use the whole premaxillary height.
> True elongation of the premax may only be valid as a ratio to skull length
> or maxilla length. I have not measured ratios on this score.

I'm also using a length/height ratio (ventral edge vs. subnarial
respectively), not a premax length / skull length ratio.

>   When *Archaeopteryx* has a shorter premaxilla (only three times longer)
> and *Confuciusornis* and other birds tend to have modified beaks to begin
> with, and that on this basis higher birds must have had to lengthen the
> premaxilla, this is convergent.

Oh come on, you don't seriously expect a nice smooth curve of values for a
character like this, with Sinornithosaurus' being taller than
Archaeopteryx's, which are taller than Sinornis', etc.?  And while
confusiusornithids have very modified beaks, Protopteryx, Sinornis, the
Spanish nestling, Eoenantiornis, etc. do not.  Therefore, there is no reason
to suspect convergence.

>   Show me an instance of a tooth developing serrations in a lineage with
> several ancestors with teeth lacking the conditions (besides fish).

Thanks David.  :-)

> It is easier then to say that loss of
> serrations is the convergent condition, but this is no more parsimonious
> and the character should be removed from cladistic matrices.

Even if a character is definitely very homoplasious, it should not be
removed from a matrix.  There still may be subsets of the apomorphic taxa
that truly share the character, like ornithomimosaurs + alvarezsaurids for
instance.

>   I lack that paper, but that's okay. I reconstruct the skull as I see the
> material in photos, not from Xu et al's figures. Sorry. My ID of the
> squamosal is based on general shape and the multi-ramal nature of the
> element.

You said you were mistaken about lacking this paper offlist, so I'll wait to
see what you think of the possibility the dorsal quadratojugal process is
actually very short, and what you think of the squamosals.

>   And how many does *Archaeopteryx*, *Unenlagia* and *Rahonavis* have? And
> actually, you did say that the length of the sterna were evident of rib
> count.

Unknown for all three, but it doesn't matter.  We don't have to show the
presence of a character in intermediates to use it as a synapomorphy between
two taxa.  I said "with each sternal plate being longer than the sacrum and
supporting about five attachments for sternal ribs", not that they were
neccessarily correlated.  I was just correcting your statement that
Sinornithosaurus "doesn't have much in the way of sterna".  Point is
Sinornithosaurus and basal birds have more than three sternal ribs, while
Velociraptor and Citipati do not.  Also, Microraptor has four pairs.

>   I think my point was that the furcula was transistory between the two,
> which would, under my end-point last post, have a variable effect on
> phylogeny... *Sinornithosaurus* is still intermediate between the "avian"
> and the "dromaeosaurid" conditions.

True, though furculae need much more study.  These morphologies have to be
better specified.

>   I thought I covered this at the end of the post. Robusticity indexes and
> neoterrestrial structures are expected. Trying to use them to explain
> avialian conditions is going to fall flat if these appear to be related to
> cursoriality and scansoriality. Tree-huggers have delicate limbs, walkers
> don't. Once the deinonychosaurs hit the ground, they required and increase
> in the robusticity to effect their larger size. *Comspognathus* was not so
> fortunate as no theory currently puts it into a guild where its direct
> ancestors were arboreal, as in Xu et al.s theory.

So your theory is that terrestrial taxa will have more robust fibulae than
arboreal/scansorial ones?  Perhaps you're right.  In addition to possible
measuring problems (this was from my old character list), there may be a
behavioral link.  Some highly cursorial taxa have robust fibulae though
(Gallimimus, Avimimus, etc.).  Also, it's odd that such probably secondarily
flightless taxa as Sinornithoides and Microvenator retained gracile fibulae,
while Velociraptor and Caudipteryx redeveloped robust ones.

>   I think I specifically refered to a mandible, not a quadrate, and that
> was of *Microraptor* (damn names...). Please be civil (I've asked before,
> but this didn't help).

So you were referring to the mandible (I was thinking of the lateral
quadrate process, oops).  I would counter with the fact that while some
basal birds (eg. Gobipteryx) have a strong lateral mandibular process, they
still only have two distal quadrate condyles.  Thus, the two characters are
not conditional.  Indeed, Clark et al. (1994) state Erlikosaurus' third
quadrate condyle does not articulate with the mandible.

> <it's easier to see in cf. Sinornithosaurus.  Archaeopteryx probably does
> lack it.  That's why it's in the "characters also found in more derived
> birds, but not Archaeopteryx" section of my list.  Again with the unknown
> Microvenator elements.>
>
>   ... which I never mentioned ...

Yes you did.  You said-
"The condyle, or the shaft? I see the element is rather flattened in aspect,
but this does not appear to be the same in pygostylians, which expand the
shaft proximal to the distal terminus (condyle). Archaeopteryx lacks it,
however, as does Microvenator."

> <Perhaps you mean Microraptor, but phalanx II-I isn't known in that genus
> either.  Could you be referring to the new skeletons (have an early copy
> of the new AMN paper perhaps)?>
>
>   Ah wonderful ...  see above about the Micro-dino names. It's not pdII-1
> that's nessesary for evaluation of the heel, however, it's pdII-2.
> Conversely, this may also indicate the presence of the greater arc on the
> distal pdII-1, but that's not really the point.

But we're talking about MANUAL phalanx II-1, not pedal phalanx II-1.
Remember, you were just talking about the manual phalanx being flattened in
pygostylians.  Regardless of whether you meant Microvenator or -raptor,
neither has a described manual phalanx II-1.

> <Please... accuracy.>
>
>   You shouldn't have jumped to conclusions when I said that. Ask
> questions.

Okay.  Why did you suddenly switch from manual phalanx II-1 flattening to
pedal phalanx II-2 proximoventral heels?  Why did you state Microraptor
lacks a flattened manual phalanx II-1.  Do you have an early copy of the new
AMN description of Microraptor?

> <Sinornithosaurus has no abrupt expansion to indicate the presence of a
> pubic foot.>
>
>   So it has to be abrupt to be a pubic foot? I was under the impression,
> as in cros pubes, that the expansion towards the distal end is a
> _degenerate_ condition from a projecting boot, but that it qualifies,
> nonetheless.

Semantics, but I DID specify "no distinct posterior pubic foot" in my
original post.  By distinct I was referring to the abrupt flaring present in
most pubic feet.

> *Microraptor* presently lacks a pubis,

Both are known from the holotype (though in anterior view, not allowing
pubic foot morphology to be described).

> <What are your mysterious "other taxa"?>
>
>   Actually, given the morphology of the heel in some troodontid pes and
> one dromaeosaur pes in my view, including *Microraptor*, *Borogovia* is
> marginalized and the pes of *Avimimus* and mononykines have this. There
> was another taxon but for some reason I can't find it. I keep thinking
> enantiornithine, but I may be wrong. It's absent in perching birds, so no
> go.

I agree Borogovia has a reduced heel, if any.  Avimimus clearly lacks the
heel, the proximodorsal lip being more extensive (Kurzanov, 1987).
Parvicursor has a similar condition and Mononykus and Shuvuuia are not
described sufficiently.

> <Which is why I don't understand why you would be trying to prove its
> existance in other taxa now.  _My_ side in this debate is that these
> "deinonychosaurian" characters are plesiomorphic for eumaniraptorans or
> eumaniraptorans + troodontids.>
>
>   Both may be equally parsimonious. Lack of your inclusion of
> *Sinovenator* may be clouding your matrix. However, it would appear that
> the polarization it offers that the robust consideration is as I have laid
> out. How long have I been saying that these last few days?

I agree that neither side is obviously correct at this point.
Sinornithosaurus could be a basal deinonychosaur, but I feel the evidence
for it being a basal avialan is at least equally strong.  Sinovenator does
influence a few of my characters, but not all.

> <Paul (DA) explicitly describes its presence in Archaeopteryx.>
>
>   Looking at several posterior and lateral/medial views of several
> *Archaeopteryx* specimens, I most certainly disagree with this.

The Eichstatt looks like it might show this condition.  Paul cites both the
left pes of the Eichstatt specimen and the right pes of the Solnhofen
specimen.

>   Once again, I reiterate the plausibility to determine either a
> archie-first or birds-higher-than-thou theory in the development or loss
> of many so-called flight-related features. Your refutation appears to be
> based on features that I myself can simply reverse in reference to Xu's
> phylogeny and find the opposite development. This makes me think that an
> evolution towards flight is a common preferrence or theme in some
> perspectives, and it may be yours, but I take a much more mechanical view
> and can easily see the loss of such structures as a mere flick of the
> avian wrist, to make magically the polarity at the base of
> Paraves/Eumaniraptora turn from flight to flightless, or vice versa.

I'm not saying dromaeosaurids aren't secondarily flightless, and indeed they
may have had more avian-looking ancestors (Bambiraptor may be an example of
this).  But Sinornithosaurus need not be one of these basal deinonychosaurs,
just like Archaeopteryx doesn't have to be basal to dromaeosaurs or
maniraptprans for a secondarily flightless scenario to be true.  You may be
able to reverse my characters' placement utilizing Xu et al.'s topology, but
they will for the most part require more steps if used that way.  Let's wait
until we get through the remaning portions of our debate before we sum up
our conclusions regarding Xu et al.'s and my characters though.

Mickey Mortimer