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

Chanaresuchus braincase



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


ABSTRACT
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.