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Re: BANDS > PADS vs. PALS
David Peters <email@example.com> wrote:
> While others are scoffing at Ruben
> (and for good reason), there's another very large group of
> "believers" that claims Pterosaurs Are Dinosaur
> Sisters (PADS) when no series of taxa anywhere within the
> Archosauromorpha shows any indication of a gradual increase
> in pterosaurian characters.
Aside from pterosaurs themselves.
> In fact, as Bennett 1996 showed (and Hone and Benton 2008
> confirmed) when you remove hind limb characters
Yes, but why would you want to do this? Pterosaurs have legs, so why not
include them in the analysis? Most of the pterosaur bauplan has been
comprehensively modified for powered flight, so (rather than representing
convergence associated with digitigrade locomotion) the hindlimb skeleton may
be best at retaining the ancestral condition.
We see the same trend with birds: the tail, pectoral skeleton (including the
forelimb), and to a lesser extent the skull show profound transformations as
the skeleton became specialized for flight. But the evolution of the hindlimb
was far more conservative over the same period.
Besides, the presence of skeletal pneumaticization and air-sacs in pterosaurs
must count for something. That wasn't known back in 1996. Dinosauromorph
affinities for pterosaurs are looking pretty good right about now.
But what we really need are basal pterosauromorphs. _Scleromochlus_ might fit
the bill; but some of its features are open to interpretation. Nevertheless,
nesting pterosaurs inside Ornithodira is not dependent on the position of