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synapomorphies not created equal
Dear All,
I've been thinking very hard about this, and I am still not convinced
that all synapomorphies are created equal. Some are "stronger" than others
no matter how long or big the evolutionary gap happens to be in which it
falls.
In my opinion, the one synapomorphy of Mammalia, the movement of the
three ossicles from the mandible into the ear of the first mammals, was
strongly selected for and occurred relatively rapidly. It is thus a very
strong synapomorphy.
In fact, that one mammalian synapomorphy may be stronger than all the
dinosaur synapomorphies (proposed by Sereno and /or Gauthier) put together.
One mammalian synapomorphy has stood the test of time, for a very long
period of time. The fact that Gauthier and Sereno felt compelled to compile
a long list of dinosaur synapomorphies indicates to me that they have no
strong confidence in any of them.
This almost cries out for the need for these purported synapomorphies
to be evaluated, and that the strongest be identified and carefully
scrutinized. The therapsid-to-mammal transition is just as well documented
(if not more so) as that of the transition to "non-dinosaurs" to dinosaurs.
Therefore the lack of a strong synapomorphy in the latter should be taken as
a strong signal that a comprehensive reevaluation is required. The question
is who will be the "Dave Peters" of dinosaur origins.
I can think of three people (at least) who could fill that role (and I
am not one of them). I can certainly try to prepare myself in case none of
them take up the challenge, but I am still relatively new at the basal
dinosaur game, and have a lot of catching up to do. I'm confident that one
of those will achieve a proper reevaluation well before I can, but given my
disappoint with what has been happening in bacteriology, I am certainly not
going to take it for granted. I believe than Crurotarsi will probably not
survive, and it is still a toss-up whether Dinosauria will survive as a
clade. Therefore those who have challenged me to come up with an
alternative set of synapomorphies will have to wait for me to catch up or
hope that those that those who need less "catching-up" will rise to the
challenge. I would prefer the latter, since I have other projects that need
attention, and strongly suspect that at least one of them will will rise to
this challenge. All I can say is the sooner the better.
------Ken Kinman
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