Re: Hanson 2006, Mortimer, Baeker response

[David Peters <davidrpeters@earthlink.net>]

"Jaime A. Headden" wrote:

>
>
>   *Lotosaurus* is allied to the crocodylomorphans.

End of argument? I've tested it against crocs and sure it's close, but no cigar.

> Dzik suggested that
> *Silesaurus* could be an ornithischian if the dentary morphology and teeth 
> were
> to be held higher than the remainder of tis postcrania, but did not follow 
> this
> up with an out-and-out referral, while other analyses of both of these taxa
> have failed to find this, though most were done outside of print and some
> presented here onlist. The extremely primitive nature of the postcrania of 
> both
> of these animals would keep them outside of Ornithischia, since it's a group
> comprised of its components, not of a single particular character or two 
> (which
> is itself highly convergent across all of Diapsida).

I agree  that a holistic approach is required and that Silesaurus falls outside 
of
traditional Ornithischia (the ones with retro pubes, etc.). But it is more
attracted to dinos than any other clade.

>
>
> <Examples of new pteros include Austriadactylus, Bakonydraco and 
> Pterorhynchus,
> all of which have nothing else exactly like them, but can be slotted into an
> existing cladogram.>
>
>   YOUR existing cladogram? *Austriadactylus* is likely either *Preondactylus*
> or another similar eudimorphodont.

What is a eudimorphodont? A wastebasket at present. And what does "likely" mean?
Let's see a tree!


> Hardly "nothing else," there, but I guess
> that qualifier "exactly" can be used to escape this, just as it can be used to
> escape ANYTHING definitive. Czerckas's pterosaur, I am not so sure. It doesn't
> appear to be an amalgam, but I've not seen xrays to determine relative
> densities of the slabs, and it appears singular and cohesive to my admittedly
> untrained eye. However, what it appears to be is a long-tailed pterodactyloid,

Wow. And extremely long-tailed at that. No gradual evolution?

>
> so I think the transition from long to short tails is simply poorly documented

Does "I think" translate here into "I believe"? I'd rather you say: "I can
demonstrate..."

> and this taxon, whatever it is, represents part of that transition.

Which part? Wouldn't it be better if _all_ the parts were in transition?


>
> *Bakonydraco* is an azhdarchid, as Osi, Weishampel and Jianu wrote in 2005,
> given both the cervical and mandibular morphologies. The absence of a lot of
> cranial material for most azhdarchids leaves its position to be founded 
> largely
> on the basis of the cervicals, while the jaw does appear to be highly similar
> to *Azhdarcho* itself.

Bakonydraco is an azhdarchid, related to Azhdarcho. The question is: what is an
azhdarchid? And are there two widely separated lineages of so-called
'azhdarchids'? Quetzalcoatlus and Co. don't seem to fit as neatly. A more
parsimonious nesting can be found elsewhere.

> <If you have a cladogram that includes all known pterosaurs and you have one
> MPT, plus the cladogram is chronologically correct and there are no untennable
> reversals, then you've achieved your goal. Note that reversals are still
> permitted, but untennable ones are not.>
>
>   The fossil record is incomplete, so why should we expect the cladogram to be
> temporally congruent?

The more taxa, the more congruent. We're getting closer to completion every day.


> Indeed, this is one of the problems with the classic
> series of horse and human evolution, which was hardly linear and "perfect" in
> it's transitions, at the same time producing both dwarfism in the lineages,
> robust taxa, and gracile taxa. That one can draw a line from beginning to end
> is a product of evolution and hindsight, but the work to produce these 
> lineages
> was acheived of over a century of investigative phylogenetic research.
> Pterosaurs have received much less in comparison, being farther from the mind
> of us humans than ourselves. But dwarfism, and other forms of reversals, occur
> periodically, and in some great abundance, for some reasons we don't know, as
> the current debate on the Flores "hominid" is currently showing. So, too,
> should pterosaurs be a wild and crazy bunch, and the deceit of a "perfect"
> result makes me VERY suspicious.

The deceit? Jaime. Where is your logic? Speaking for myself, I am made 
suspicious
by 34,000 MPTs. Or 34 MPTs. Why aren't you?

>
>
> <So, knowledge of the fossil record is incomplete in one sense, but complete 
> in
> another. Sorry. Some of the mystery is gone now.>
>
>   In one's own mind perhaps. The fossil record will never be complete. New 
> taxa
> cannot be expect to simply "line up" or "slot in", as *Silesaurus* _clearly_
> shows.

Add taxa to your cladogram and Silesaurus will slot in. In fact, it has to. PAUP
includes everything. God bless, PAUP.

>
>
> <You sound like a referee. Afraid of the 'danger' of finding a really good
> cladogram.>
>
>   I myself am afraid of the danger of someone saying they have a really good
> cladogram. This is a personal deceit, that one mught think their result is so
> clean or perfect as to not require introspection,

On the contrary. I invited attacks.

> or to simply start from
> group-up and over again, in order to duplicate the results. One to dismiss
> ephemeral "adults" and traced "characters" in order to advance one's own
> knowledge, not just to satisfy a doubting few. If someone starts saying their
> cladogram is "really good" because of their perfect MPT results and so-called
> chronological linearity, then I would wash my hands of this. There are several
> other cladograms out there, published, that contest this phylogeny, and we can
> be self-assured this means no one has NEAR the perfect knowledge claimed by
> Dave.

If there are problems with my cladogram, please point out which taxa are 
misplaced
and why. The only stipulation I would put upon you is this: you must not exclude
any taxa. With exclusion come manipulation.

>
>
> <Just as I have tested this cladogram in every way possible, this is a
> challenge to others to let it get published and/or test it yourself.>
>
>   The tracing method should be publically aired and scrutinized before your
> results using it in a phylogeny published. This allows us to test the means by
> which it seems a large number of the results have been produced from.

You say: it seems. That means: you guess. Regardless if I use voodoo or dreams,
the results, if wrong, should have glaring errors of logic in relationships. As 
I
have done with Hanson's cladogram, find the glaring errors in mine and report 
them
to me. Otherwise you, by your logic, will be forced to admit that I have
constructed a 34,000 box cladogram of intricate errors that somehow resulted in 
a
single MPT that is chronologically ordered, and a spectral blend of morphologies
from the phalangeal proportions to the tooth counts. I think a roomful of 
monkeys
could type Shakespeare before that could happen.

>
>
> <A cladogram, I remind you, is a hypothesis. I promote this particular
> hypothesis because it works in every way. A hypothesis doesn't prove anything,
> but it is the best evidence (and usually they are widely accepted) that we
> have.>
>
>   An hypothesis is not evidence. The fossils are the evidence, and it's the
> personal projection that the features have meaning that lend themselves to a
> system of relationship. We have tested THAT particular interpretation to the
> virtual satisfaction of the entire scientific community, but cladograms are a
> way of doing this relationship-ratcheting algorithmically. That requires the
> hypothesis that the algorithm represents an accurate means of deriving
> information from the evidence, and that the results are a way to interpret it.
> Thus a cladogram itself is also not evidence, but a projection of an
> hypothesis, the hypothesis being the matrix (which is not available to us to
> test).

Yes it is. In their rage against tiny pteros, no one has bothered to request it.


> Since the very methods of deriving that matrix are at question, it would
> be highly circumspect not to publish on the means prior to the ends.

So, if suspect, you are saying, you're not interested in seeing it? It doesn't
matter. You don't need it. I didn't see Hanson's matrix and was able to find 
logic
flaws simply in its order. You can do the same with mine.

>
>
> <Let's say that No. 9 is a juvenile. What is it a juvenile form of? Be 
> specific
> and show evidence that it is indeed the candidate you propose and that it
> doesn't have more evidence (remember parsimony) that it is closer to my
> candidate.>
>
>   It could be a juvenile of its own species.This doesn't stop it from being a
> juvenile.

I can live with that. But then in a lineup of sister taxa an adult large enough 
to
pass such an embryo/juvenile would be several magnitudes larger than its 
sisters.
That would be a red flag. Not insurmountable, but a concern.


> It could be a juvenile of *Pterodactylus kochi*, not that I really
> care, or of *P. antiquus*.

Have you compared pelvic openings? No. 9 is really not that small compared to 
P.k
and P.a.

> But this doesn't stop it from being a juvenile. We
> can also argue that the juvenile *P. micronyx* is a ctenochasmatid, but of 
> what
> more-nested is not certain, possibly either *Ctenochasma* or *Gnathosaurus* or
> one of its relatives (parsimony would have us place it into an existing taxon
> than coin a new one of equivalent standing, and it simply seems "cleaner" that
> way to be LESS assumptive than MORE asusmptive about our taxonomy).

Just to shed light on this whole morass, No. 13 could be a baby cycnorhamphid, 
but
it could also be a tiny cyc. And we all remember baby Pterodaustro. It 
definitely
is a baby. The others in the wastebasket of P. micronyx need to be referred to 
by
number as many are morphologically distinct.

>    The homeothermy (or absence of it) in pterosaurs and its prescence 
> throughout
>
> ontogeny would be expected in an argument of flight-capable juveniles that 
> were
> precocial or super-precocial, and would require they were born highly active,
> possibly without parental care, etc. This would also explain away virtually 
> all
> of Dave's hypotheses regarding juveniles appearing like adults, since the
> body-size and mass relative to wingshape and loading will differ as the
> pterosaurs scale up, and thus may not be phylogenetically informative without 
> a
> growth series. However, Dave's phylogeny does not look for a growth series, as
> others have done outside of phylogeny, and this is a failing of the cladistic
> system Dave is operating in, and was why Dr. BÃ?ker spent half of his post
> suggesting other paradigms to consider.

Actually, as in Pterodaustro and No. 13, some tiny pteros do nest with their 
adult
counterparts. So, my phylogeny does find and confirm certain growth series.

David



>
>
>   Cheers,
>
> Jaime A. Headden
> http://bitestuff.blogspot.com/
>
> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
>
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