RE: Gondwanan theropods: new papers by Novas and colleagues

[Tim Williams <twilliams_alpha@hotmail.com>]

Quoting Novas and Agnolin (2004):

> Unquillosaurus ceibali Powell, a giant maniraptoran (Dinosauria, Theropoda)
> from the Late Cretaceous of Argentina. [snip]
>
> However, the pubic anatomy of Unquillosaurus is
> more congruent with that present in metornithine coelurosaurians, a group
> including Alvarezsauridae, Therizinosauroidea, Oviraptorosauria,
> Deinonychosauria, and Aves.

I wonder if this will revive the notion that _Unquillosaurus_ and 
_Unenlagia_ are closely related, and perhaps even belong in the same genus 
(as raised on the DML)?  _Unenlagia_ does come from the Rio Neuquen 
Formation, however.

BTW, the pubis of _Unenlagia_ measures about 30 cm long, compared to 51 cm 
for the _Unquillosaurus_ pubis.  Novas and Puerta (1997) estimate a length 
of 2.3m for _Unenlagia_.  If _Unquillosaurus_ was of comparable morphology 
to _Unenlagia_, this gives a body length of around 4m for _Unquillosaurus_.  
Not a huge theropod by any means.

> Derived features present in Unquillosaurus include: opisthopubic pelvis,

I'll have to read the paper to ascertain how Novas and Agnolin infer an 
opisthopubic pelvis for _Unquillosaurus_ based only on an isolated pubis.  
> From the shape/angle of the articulations with the ilium and/or ischium, 
perhaps?

> pubic pedicle of ilium craniocaudally wide, ventral margin of pubic pedicle 
> strongly concave, cranial process of pubic foot short, and length of pubic 
> foot less than 30 percent of pubic total
> length. Moreover, some traits shared with early avians (e.g., pubic foot 
> proximodistally tall and craniocaudally short),

All these features are also seen in _Unenlagia_.



Tim

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