Pissarrachampsa, new baurusuchid from Brazil in PLoS One

[bh480@scn.org]

From: Ben Creisler
bh480@scn.org

In PLoS ONE (with free pdf, of course!):

Montefeltro, F.C., Larsson, H.C.E., & Langer, M.C. (2011) 
A New Baurusuchid (Crocodyliformes, Mesoeucrocodylia) 
from the Late Cretaceous of Brazil and the Phylogeny of 
Baurusuchidae. 
PLoS ONE 6(7): e21916. 
doi:10.1371/journal.pone.0021916
http://www.plosone.org/article/info%3Adoi%2F10.1371%
2Fjournal.pone.0021916

Baurusuchidae is a group of extinct Crocodyliformes with 
peculiar, dog-faced skulls, hypertrophied canines, and 
terrestrial, cursorial limb morphologies. Their 
importance for crocodyliform evolution and biogeography 
is widely recognized, and many new taxa have been 
recently described. In most phylogenetic analyses of 
Mesoeucrocodylia, the entire clade is represented only by 
Baurusuchus pachecoi, and no work has attempted to study 
the internal relationships of the group or diagnose the 
clade and its members.

Based on a nearly complete skull and a referred partial 
skull and lower jaw, we describe a new baurusuchid from 
the Vale do Rio do Peixe Formation (Bauru Group), Late 
Cretaceous of Brazil. The taxon is diagnosed by a suite 
of characters that include: four maxillary teeth, 
supratemporal fenestra with equally developed medial and 
anterior rims, four laterally visible quadrate fenestrae, 
lateral Eustachian foramina larger than medial Eustachian 
foramen, deep depression on the dorsal surface of 
pterygoid wing. The new taxon was compared to all other 
baurusuchids and their internal relationships were 
examined based on the maximum parsimony analysis of a 
discrete morphological data matrix.

The monophyly of Baurusuchidae is supported by a large 
number of unique characters implying an equally large 
morphological gap between the clade and its immediate 
outgroups. A complex phylogeny of baurusuchids was 
recovered. The internal branch pattern suggests two main 
lineages, one with a relatively broad geographical range 
between Argentina and Brazil (Pissarrachampsinae), which 
includes the new taxon, and an endemic clade of the Bauru 
Group in Brazil (Baurusuchinae).