[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Fingers and Thumbs



On Tue, Jun 23, 2009 at 12:09 PM, john hunt <john.bass@ntlworld.com> wrote:
>
> It seems to me that the most likely mechanism for digit loss would be a
> phalange

I see and hear a lot of people make this error -- the singular is
"phalanx". (Same as the military term -- the word originally mean
"stick", IIRC. Hmm, maybe we should just call them "sticks".... :])

> at a time rather than simultaneous reduction of all phalanges to
> nothing. ÂWhat does the evidence say about this?

I'm no developmental expert, but both seem equally likely to me,
depending on where in the developmental pathway the mutation occurs.

> If the evidence supports the model of phalanges being lost it does not make
> the loss a phalange from II to make it look like I so unusual.

The authors of _Limusaurus_ observe some possible morphological
similarities between digit II of that taxon and digit I of non-avepod
saurischians (i.e., the "twist" in phalanx I). Seems like that
interpretation is open to debate, though.
--
T. Michael Keesey
Technical Consultant and Developer, Internet Technologies
Glendale, California