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Caipirasuchus (Late Cretaceous notosuchian), new species from Brazil



From: Ben Creisler
bcreisler@gmail.com

New in PLoS ONE:

Diego Pol, Paulo M. Nascimento, Alberto B. Carvalho, Claudio
Riccomini, Ricardo A. Pires-Domingues & Hussam Zaher (2014)
A New Notosuchian from the Late Cretaceous of Brazil and the Phylogeny
of Advanced Notosuchians.
PLoS ONE 9(4): e93105.
doi:10.1371/journal.pone.0093105
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0093105

A new notosuchian crocodyliform from the Late Cretaceous Bauru Group
found in the southeastern State of São Paulo (Brazil) is described
here. The new taxon, Caipirasuchus stenognathus, is referred as a new
species of the recently erected genus Caipirasuchus within the clade
Sphagesauridae based on a phylogenetic analysis of basal
mesoeucrocodylians. Caipirasuchus stenognathus is represented by an
almost complete skull and lower jaw that has autapomorphic characters
that distinguish it from other species of Sphagesauridae. These
autapomorphies include: maxilla forming part of the orbital margin
(absence of lacrimal-jugal contact), nasal with smooth depressions on
the posterior region close to the contact with the maxilla and
lacrimal, postorbital with posterior palpebral facet that extends
posteriorly underneath the ear-flap groove, and a distinct anterior
process of the medial flange of the retroarticular process.
Additionally, the new taxon lacks autapomorphic features described in
other sphagesaurids. The phylogenetic analysis results in a
monophyletic genus Caipirasuchus, that is the sister group of a clade
fomed by Sphagesaurus huenei, Caryonosuchus pricei, and
Armadillosuchus arrudai. Sphagesaurids also include a basal clade
formed by Adamantinasuchus navae and Yacarerani boliviensis. Other
notosuchian taxa, such as Mariliasuchus amarali, Labidiosuchus amicum,
Notosuchus terrestris, and Morrinhosuchus luziae are successive sister
taxa of Sphagesauridae, forming a clade of advanced notosuchians that
are restricted to the Late Cretaceous of South America. These results
contrast with most previous phylogenetic hypotheses of the group that
depicted some members of Sphagesauridae as more closely related to
baurusuchids, or found Asian (e.g., Chimaerasuchus) or African
(Malawisuchus, Pakasuchus) forms nested within advanced notosuchians
that are, according to our analysis, endemic of the Late Cretaceous of
South America.