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Re: Chanaresuchus braincase

Not quite dinosaurian, but thanks for the release!

2012/6/26 Ben Creisler <bcreisler@gmail.com>:
> From: Ben Creisler
> bcreisler@gmail.com
> In the new JVP:
> María J. Trotteyn & José A. Haro (2012)
> The braincase of Chanaresuchus ischigualastensis (Archosauriformes)
> from the Late Triassic of Argentina.
> Journal of Vertebrate Paleontology 32(4):867-882
> DOI:10.1080/02724634.2012.670178
> http://www.tandfonline.com/doi/abs/10.1080/02724634.2012.670178
> Here, we present information regarding the braincase anatomy of
> Chanaresuchus ischigualastensis, from the Ischigualasto Formation
> (Carnian) of Argentina. The braincase is very similar to that
> previously described for Chanaresuchus bonapartei, but bears some
> differences: rostral contour of the basal tubera nearly transversely
> oriented in ventral view; basal tubera with rounded distal tips in
> ventral view; paroccipital processes with a slight distal widening in
> caudal view; sulcus on the caudal surface of each paroccipital process
> restricted to the proximal two-thirds of the latter; and
> parabasisphenoidal ventral surface transversely concave. A
> phylogenetic analysis was performed using exclusively neurocranial
> characters, including a few new characters, to investigate
> phylogenetic hypotheses suggested by the neurocranial evidence. The
> neurocranial data support a sister-group relationship between
> Chanaresuchus ischigualastensis and C. bonapartei, on the basis of the
> presence of an intertuberal plate with a concave border. Our analysis
> also suggests the monophyly of a group formed by both species of
> Chanaresuchus and Proterochampsa. This group was supported by one
> apomorphy: the paroccipital processes are elongated relative to their
> height, which did not show homoplasy in our results. Our results show
> that Doswellia is the sister group of the clade formed by these
> proterochampsids, supporting inclusion of the former within the
> Proterochampsia, and this clade is recovered as more closely related
> to archosaurs than to Euparkeria.