A New Baurusuchid (Crocodyliformes, Mesoeucrocodylia) from the Late Cretaceous of Brazil and the Phylogeny of Baurusuchidae

Abstract

BackgroundBaurusuchidae 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.Methodology/Principal FindingsBased 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.ConclusionThe 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).

Reptiles Extintos - Volumen en Homenaje a Zulma Gasparini

“…America (and other regions of Gondwana) has remarkably increased since the original studies of Gasparini in the 1970's and 1980's (Carvalho and Bertini, 1999;Ortega et al, 2000;Campos et al, 2001;Carvalho et al, 2004Carvalho et al, , 2005Carvalho et al, , 2011Pol and Apesteguía, 2005;Nobre and Carvalho, 2006;Andrade and Bertini, 2008;Carvalho, 2009, 2011;Kellner et al, 2009Kellner et al, , 2011aMarinho and Carvalho, 2009;Nascimento and Zaher, 2010;Montefeltro et al, 2011;Martinelli et al, 2012;Marinho et al, 2013). The new discoveries, coupled with the inclusion of both Baurusuchidae and Peirosauridae within Notosuchia in recent phylogenetic studies (e.g., Turner and Sertich, 2010;Pol et al, 2012Pol et al, , 2014, revealed a previously unsuspected diversity of Notosuchian crocodyliforms.…”

“…A strong component of recent research on notosuchians has been the use of cladistics analysis for testing the relationships of Notosuchia Pol, 2003;Carvalho et al, 2004;Turner and Sertich, 2010;Andrade et al, 2011;Montefeltro et al, 2011;Pol et al, 2012Pol et al, , 2014. Many of these studies are now corroborating the monophyly of the four Cretaceous clades early recognized by Gasparini for South American forms in pioneer contributions during her early career (i.e., Uruguaysuchidae, Peirosauridae, Baurusuchidae, and a clade allying Notosuchus and closely related forms; Gasparini, 1971Gasparini, , 1972Gasparini, , 1982.…”

“…3). The fifth clade, Baurusuchidae, is mainly recorded in two formations from the middle Late Cretaceous of Argentina (Cynodonthosuchus, Wargosuchus; Woodward, 1896;Martinelli and Pais, 2008) and Brazil (Baurusuchus, Campinasuchus, Pissarrachampsa, Aplestosuchus, Gondwanasuchus;Price, 1945;Carvalho et al, 2011;Montefeltro et al, 2011;Marinho et al, 2013;Godoy et al, 2014;) Antunes, 1975;Company et al, 2005;Rabi and Sebök, 2015) in a separate group.…”

“…As noted by several authors (e.g., Montefeltro et al, 2011;Pol et al, 2014;Martinelli and Teixeira, 2015), there is some uncertainty related to the age of the Adamantina Formation, which provides over 80% of the known taxic diversity of advanced notosuchians and baurusuchids. Such uncertainty may imply this radiation event occurred in South America during the SantonianCampanian rather than during the Turonian-Santonian.…”

Revisão sistemática e ontogenética dos materiais cranianos atribuídos ao gênero Mariliasuchus (Crocodyliformes, Notosuchia) e suas implicações taxonômicas e paleobiológicas

“…Formas hipercarnívoras, como Baurusuchidae e Sebecidae, apresentam como característica marcante a presença de uma dentição claramente zifodonte (sensu Prasad & Broin, 2002), com uma coroa dentária comprimida lateralmente e carenas com serrilha formada por baterias longitudinais de dentículos, num padrão semelhante à dentição encontrada em Theropoda (Pinheiro et al, 2008;Montefeltro et al, 2011;. Algumas filogenias unem estes táxons hipercarnívoros, como Baurusuchus e Sebecus, dentro de um clado mais abrangente, como Sebecosuchia (Pol, 2003) ou Baurusuchoidea (Carvalho et al, 2004), enquanto outras não apontam para uma relação próxima entre os dois grupos, deixando os Sebecidae fora de Notosuchia (Sereno & Larsson, 2009;Holliday & Gardner, 2012).…”