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Re: definition






Mike,
The classic case of "sedis mutabilis" (position changeable) is the trichotomy (or any polytomy for that matter). One is unable to tell which of three (or more) groups split off first.
In the Kinman System, _sedis mutabilis_ is coded by repeating a letter (rather than a cladistic sequence of letters). Here is an example using a dinosaur clade (remember that I tend to recognize very broad "lumped" families). The first shows the three families cladistically coded, but the second shows a trichotomy (each coded with an A) if one is rather uncertain about the branching order:
4A Therizinosauridae (segnosaurs)
B Caudipteridae (incl. Nomingia)
C Oviraptoridae (oviraptorosaurs)
And the same three families coded _sedis mutabilis_:
4A Therizinosauridae
A Caudipteridae
A Oviraptoridae
I am still debating whether to include _Microvenator_ in Oviraptoridae or listing it as a separate plesion.
And by the way, the coding for incertae sedis is simply a question mark.
------Ken
********************************************************
From: "T. Mike Keesey" <tmk@dinosauricon.com>
Reply-To: tmk@dinosauricon.com
To: -Dinosaur Mailing List- <dinosaur@usc.edu>
Subject: Re: definition
Date: Wed, 7 Feb 2001 17:38:14 -0500 (EST)

On Wed, 7 Feb 2001 Dinogeorge@aol.com wrote:

> In a message dated 2/7/01 3:40:50 PM EST, crnoto@midway.uchicago.edu writes:
>
> << In the mean time, I was wondering if some one knew what "incertae sedis"
> means. >>
>
> "Of doubtful position." "Incertitude" means insecurity or doubtfulness, and
> it's from the same Latin root. "Sedis" is literally a "seat," "place," or
> "home."


I always interpreted it as "of uncertain position", i.e., if something is
Dinosauria _incertae sedis_, you know it's a dinosaur, but you're not sure
where inside Dinosauria it belongs.

There's also _sedis mutabilis_, which would mean something like "changing
position".
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