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Fw: digits was: Sneak Peak at Yale Torosaurus Sculpture



Dear List,

    Mickey asked me to forward this. His server is acting up.

Cliff
----- Original Message ----- 
From: "Michael Mortimer" <mickey_mortimer111@msn.com>
To: <dinonaut@emerytelcom.net>
Sent: Tuesday, September 27, 2005 6:32 PM
Subject: RE: digits was: Sneak Peak at Yale Torosaurus Sculpture


>
> Cliff Green wrote-
>
> >     Thank you for the great information. I suppose I stand corrected on
> >the
> >duckbills, but don't most of that clade have a missing first digit, with
> >numbers two through four fused into a hoof like structure? Is the fifth
> >digit clawed, or no? I guess with that argument you could say
tyrannosaurs
> >also had unguals on digits four and five, but you can no longer see them
> >because they evolved away.  Is there evidence of unguals in the forth and
> >fifth digits of Large ceratopsians, stegosaurs, and armored dinosaurs?
>
> Your're right about hadrosaurid manus configuration (no digit I, digits
> II-IV joined, digit V divergent).  Horner et al. claim digits IV and V end
> in unguals, describing the one on IV as elongate with an arcuate cranial
> margin and V as being ovoid.  I can't confirm this though, as my
hadrosaurid
> postcranial literature is lacking.  It's not at all analogous to
> tyrannosaurs.
> As for stegosaurs, Stegosaurus is said to have cartilaginous terminal
> phalanges on digits III-V (Galton and Upchurch, 2004).  Most other
> stegosaurs don't preserve much manual material.
> The ankylosaur Liaoningosaurus seems to have an ungual on its fourth
digit,
> but the brief description and small figure make this uncertain (Xu et al.,
> 2001).  Other ankylosaurs are said to have from 3-4 phalanges on digit IV,
> so I wouldn't put it past them to have unguals there too.  But I lack
> Maryanska (1977), so can't tell at the moment.
> Ceratopsids are said to lack unguals on digits IV and V by Penkalski and
> Dodson, which is why they were insure about Avaceratops.
>
> Mickey Mortimer
>
>