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Re: Effigia [was Defending Photoshop]



David Peters (davidrpeters@earthlink.net) wrote:

<I'm just posting a red flag. Something doesn't look as stated.>

  And I am saying you should not try to point such a thing out without looking
atg the whole, such as identifying a discrete element from a mess of irregular
cracks across the hole frontal with a pattern of largely being longitudinal. At
this point, any other identified bones become incredibly speculative.

<Nobody has done a reconstruction of Ticinosuchus since Krebs, And someone
needs to. It's not your typical rauisuchian.>

  It looks like a typical prestosuchid with gracile qualities, but then, I've
not seen a lot of bones of this animal myself. The figures from Kreb's
reconstruction are not evidence of anything.

<Just another red flag. Often WYSIWYG in fossils, 'repairs' (like making sure
heavy sauropod tails contact the groud) to the contrary.>

  One could easily keep the tails in "articulation" and slope the tails just as
one could keep sauropod necks in articulation and give them a fair bit of
vertical curvature.

<As Al Franken used to say, "And that's... ok">

  Yes, indeed, and expected. My dear wonderful commentator "Reb." Franken (who
has a charming way of talking) is very funny, but I don't think he has much of
a grasp on principles of biology. Small animals typically have large orbits, an
effect of paedomorphosis and little peramorphic alteration, giving us adults
that mature into juvenile features. But they are clearly adult given their
mature bone structure, they have ossified bones, and even ossified epiphyses,
yet have heads larger for their bodies, huge orbits, small snouts (extant crocs
such as the dwarf caiman show the same features).

<Ticinosuchus was not a biped. Or can you show me that it was?>

  Given that the prestosuchid line such as *Saurosuchus* and the more derived
near-poposaur *Postosuchus* were all erect-limbed with preacetabular alae in
their ilia and advanced metatarsal  structure adhering to one another with
reduced calcanial tubers, I have no difficulty imagining that the femoral
anatomy is of the non-basal, non-sprawling type developed in only a few
lineages of crocodylian: "Rauisuchia" and "Sphenosuchia". Once, long ago, Dave
Peters argued a preacetabular ala indicated a biped, so why is this taxon any
different? However, I did make a mistaken corellation before, by indicating
that the inturned femoral caput was typical of bipeds. It is, but it's more
indicative of erect femoral posture, which leads to cursorial specialization of
the hindlimb, and thus bipeds will always have the hindlimb structure, at least
obligate and most faculative one. I am not counting basilisk lizards which only
run this way when prompted, they don't do this for the purpose of just "getting
around." I hope this helps clarify.

<The key thought here is that Ticinosuchus led to at least two branches now,
the bipeds and the armored ones, much as early dinosaurs led to theropods and
scuttellosaurs. So, it can happen. Try not to apply too many aeotosaur
characters to something that is not an aetosaur. Some characters, yes, but pick
the correct characters, before and after the split.>

  What primary data do you have on *Ticinosuchus* to begin with? Krebs'
reconstruction?

<Same comments as above with the addition of: can you find ANY other taxa with
a dentary a brief or nearly so? And with a mandibular fenestra a extensive or
nearly so. We're just looking for a best match among candidates known to date.>

  I would rather examine the real jaws and not a curious reconstruction. I
would never use the figures given as primary data, and nor should Dave. As for
extensive external mandibular fenestra, there are some animals with an EMF that
extends nearly to the symphysis of the mandible, and others with an EMF more
than 50% the jaw length. This was one set of features that Maryanska et al.
used back in 2001 to support an avian-origin of oviraptorosaurs, given the jaw
anatomy of *Caudipteryx* beign similar to *Confuciusornis*. Both are quite
different from one another. Short dentaries are also a functional dietary
feature, and while they may be phylogenetically informative, I would again be
speculative about their use in comparing two different animals. The host of
other data and contradictions I posted shows that shortening of the dentary _IF
PRESENT_ (since you don't know how much of the jaw is really THERE in
*Effigia*), that it would be convergent.

<And that's okay. After all, many dinosaur bipeds lost their ancestral scutes
too.>

  Like, what, ALL of them? It was the ancestral dinosaurian condition to LACK
the scutes! Even *Marasuchus*, a nondinosaur, lacks them.

<No, PAUP nested it there based on discrete data points. And it's not a typical
dinosaur, Jaime. It's one of the cuzzins no one talks about.>

  One seems to have misinterpreted what I said. When I referred to interpreting
*Lotosaurus* as a dinosaur, I was in fact referring to these troubling issues
of under or overinterpreting the photoshopping methods of trying to "find"
features. Indeed, the presence of a LARGE postfrontal, a massive prefrontal and
thin, low lachrymal with more of the anterior margin of the orbit formed from
the prefrontal than the lachrymal are only CRANIAL features of the *Lotosaurus*
holotype not found in dinosaurs but found in crurotarsans. Later on, Dave
writes:

<You need to do the phylogenetic analysis before saying such things, Jaime.
Fight facts with facts, not words. It doesn't matter if a few to many
characters are different than typical, it's the aggregate that counts.
Parsimony, in other words. Otherwise you're a follower of brother Larry Martin
who says, "Show me one character that is unmistakeably avian among theropods."
And of course, one character can always be found elsewhere, due to convergence,
somewhere else. re: Clark and Wu, It's out of my hands. But good suggestion.>

  There HAVE been phylogenetic analyses including *Lotosaurus*. But instead of
analyzing the data, Dave has simply criticized the supra"generic" taxa
included, and has, as with Benton's analysis, simply ignored it. Indeed, so
far, Dave has ignored the arguments I have made about the non-dinosaurian
features of *Lotosaurus* without showing what explicit ornithischian or even
dinosaurian features are known in *Lotosaurus* to the exclusion of crurotarsan
features.

<Interesting statement considering you have not seen the data. Next are you
going to accuse me of having the devil's mark on a part of my body typically
hidden from view. Don't go there, Jaime. It's not good for you. Fight PAUP with
PAUP.>

  I don't need to shove my interpretations and codings at yours. I want YOU to
find a way to explicitly PROVE your codings. And be able to substantially
include ACCURATE data for competing hypotheses. That is, IF you're actually
_testing_ anything.

<And you forgot to say: It's still a Newtonian universe.>

  Newton did get things right, but I'd argue its an Einstein universe now,
i.e., relativistic.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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