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RE: Gondwanan theropods: new papers by Novas and colleagues



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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