Reassessment of the enigmatic crocodyliform "Goniopholis" paulistanus Roxo, 1936: Historical approach, systematic, and description by new materials

Abstract

The Crocodyliformes are the most represented vertebrate clade in the Upper Cretaceous sequences of the Bauru Group, Paraná Basin. However, some of the species described have an uncertain taxonomic status and phylogenetic position. For instance, “Goniopholis” paulistanus has been assigned as a nomem dubium, due to its description being based on scarce material. The “G”. paulistanus specimens (i.e. teeth and a left tibia) were discovered in two different localities in São Paulo state: Mirandópolis and Valparaíso municipalities; where the upper interval of the Adamantina Formation (Early Maastrichtian of Bauru Group) crops out. Revisiting these specimens, we observed multicrenulated teeth in middle dentary toot- row, a remarkable feature only shared with teleosaurids Machimosaurus hugii (Upper Jurassic of Laurasia) and M. rex (Lower Cretaceous of Tunisia). This apomorphy was also recognized in new material from the Alfredo Marcondes municipality (Presidente Prudente Formation), which are here also referred to “G”. paulistanus. We recognized the teeth of “G.” paulistanus as the lectotype, however the tibia cannot be assigned to a species as it was not collected in association with the teeth. We performed a phylogenetic analysis with a data matrix composed of 388 characters and 86 taxa, analyzed in TNT. The strict consensus tree recovered Neosuchia and Ziphosuchia (Notosuchia + Sebecia) within Mesoeucrocodylia. The species “G” paulistanus is valid, as a distinct and new genus within Sebecia, in a polytomy with Barreirosuchus, Pepesuchus, Itasuchus and Peirosaurus, forming the clade Itasuchidae. Stolokrosuchus is the sister taxon to Itasuchidae, the sister group of all other Sebecia (Peirosauridae (Mahajangasuchidae + Sebecidae and taxa affinis)). The clades Ziphosuchia, Sebecia and Itasuchidae are here redefined, and we find the last two clades to be more closely related to terrestrial notosuchids than to semiaquatic neosuchians.

The firstCaipirasuchus(Mesoeucrocodylia, Notosuchia) from the Late Cretaceous of Minas Gerais, Brazil: new insights on sphagesaurid anatomy and taxonomy

“…Particularly, Baurusuchus occurs in the state of São Paulo with Caipirasuchus stenognathus and other sphagesaurid material (e.g., Armadillosuchus arrudai ), contrary to what is seen in Triângulo Mineiro. Recently, Pinheiro et al (2018) identified four Crocodyliformes Assemblages Zones (AZ) within levels of the Adamantina and correlated or partially correlated formations in Minas Gerais and São Paulo states within a sequence stratigraphic framework. The authors also mentioned the lack of appropriated biostratigraphic correlations and the difficult to perform it, in part due to taxonomic problem with some taxa and also biases in the fossil record.…”

“…The Vale do Rio do Peixe, Presidente Prudente, São Jose do Rio Preto, and Araçatuba formations were the units proposed in substitution to part of the Adamantina Formation ( Fernandes, 1998 ; Fernandes & Coimbra, 2000 ). Nevertheless, the use of the Adamantina Formation is still favoured over the alternative terminology (applied to the state of São Paulo state), especially in works regarding the outcrops in the Triângulo Mineiro region, in which Campina Verde is located ( Paula e Silva, Kiang & Caetano-Chang, 2009 ; Batezelli, 2010 ; Batezelli & Ladeira, 2016 ; Menegazzo, Catuneanu & Chang, 2016 ; Pinheiro et al, 2018 ). Thus, we opted to follow these more recent geological contributions and favor use of Adamantina Formation in the Triângulo Mineiro region.…”

First dinosaur record from the Marília Formation (Maastrichtian) in the Gurinhatã municipality, Minas Gerais state, Brazil

“…This unit was developed during the Late Cretaceous, deposited during the Gondwana breaking-up (Fernandes & Coimbra, 2000). The Bauru Group crops out in parts of various Brazilian states, and a detailed stratigraphic review can be seen in some more recent works (e.g., Pinheiro et al, 2018).…”

“…Among the eight formations that compose the Bauru Group (sensu Pinheiro et al, 2018), in the Gurinhatã municipality outcrops the Adamantina and Marília formations (Fig. 2).…”

“…2). The specimen described in this work comes from strata of the Marília Formation, which strata are mainly dated from Maastrichtian (Dias-Brito et al, 2001;Brusatte et al, 2017), This formation is dominated by sandstones and conglomerates, which are often cemented by carbonate (limestone) and some carbonate concretions (Brusatte et al, 2017;Pinheiro et al, 2018) and interpreted as alluvial fan-like (Riccomini, 1997), later reworked by an interlaced system in association with limestone and lacustrine calcareous sediments (Barcelos & Suguio, 1987). Lastly, the Marília Formation is traditionally divided into three subunits (Serra da Galga, Ponte Alta & Echaporã members, sensu Barcelos, 1984).…”