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Feduccia and dino-hand questions
Been cogitating on the Feduccia and Burke paper before I'm able to really
sit down and tackle it.
One question that comes to mind is whether the known pentadactyl theropod
manuses, such as _Herrarasaurus_, been found fully articulated? I'm still
interested in tracking down why the dinosaur manus couldn't be II-III-IV.
Another question has to do with a paragraph in the paper that I've read a
dozen times and am not sure I understand:
"As the primary axis invariably gives rise distally to digit IV in
amniotes, it serves as a consistent marker of digital identity and assigns
the homologies of the reduced bird hand as digits II-III-IV. A variation of
this pattern wherein the primary axis runs through digit III, would
eliminate any phylogenetic significance from the morphological and molecular
similarities in amniote limb development. If such a condition could be
demonstrated, patters of limb development would have to be decoupled from
phylogeny, and this stereotypic pattern of development accepted as convergence."
Uh, what? Does he really mean that if bird digits are I-II-III,
developing with III as the primary axis, then there is no phylogenetic
significance in the development of any amniote limb? Is he really saying
that if this is the case, the development of every other amniote limb from a
primary axis through IV is simply convergence? Despite the fact that the
"aberrant" development occurs in only a single lineage?
Does that make no sense to anybody else?
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