TL;DR: This discovery confirms that baurusuchids were top predators of their time, with sphagesaurid crocodyliforms occupying a lower trophic position, possibly with a more generalist diet.
Abstract: A new Baurusuchidae (Crocodyliformes, Mesoeucrocodylia), Aplestosuchus sordidus, is described based on a nearly complete skeleton collected in deposits of the Adamantina Formation (Bauru Group, Late Cretaceous) of Brazil. The nesting of the new taxon within Baurusuchidae can be ensured based on several exclusive skull features of this clade, such as the quadrate depression, medial approximation of the prefrontals, rostral extension of palatines (not reaching the level of the rostral margin of suborbital fenestrae), cylindrical dorsal portion of palatine bar, ridge on the ectopterygoid-jugal articulation, and supraoccipital with restricted thin transversal exposure in the caudalmost part of the skull roof. A newly proposed phylogeny of Baurusuchidae encompasses A. sordidus and recently described forms, suggesting its sixter-taxon relationship to Baurusuchus albertoi, within Baurusuchinae. Additionally, the remains of a sphagesaurid crocodyliform were preserved in the abdominal cavity of the new baurusuchid. Direct fossil evidence of behavioral interaction among fossil crocodyliforms is rare and mostly restricted to bite marks resulting from predation, as well as possible conspecific male-to-male aggression. This is the first time that a direct and unmistaken evidence of predation between different taxa of this group is recorded as fossils. This discovery confirms that baurusuchids were top predators of their time, with sphagesaurids occupying a lower trophic position, possibly with a more generalist diet.
TL;DR: A new Pissarrachampsinae specimen is presented, which challenges the proposed chronostratigraphic separation between the Sao Paulo and Minas Gerais baurusuchids, suggesting that both groups lived at about the same time.
TL;DR: In this article, the first tridimensional digital reconstruction of individualized skull bones for Baurusuchia was presented, and the new species differs from all the other known baurusuchids by a depression on the posterior portion of the nasal bearing a crest, an infraorbital crest of the jugal that extends until the anterior margin of the lacrimal, the dorsal surface of the frontal lacking a longitudinal crest or depression and the lateral convexity of the squamosal prongs participating in the occipital wall.
Abstract: Baurusuchidae is one of the most diverse groups of South American notosuchians, unambiguously recorded in Late Cretaceous deposits of Brazil and Argentina. The group is characterized by a reduced tooth formula, a lateromedially compressed rostrum, and a verticalized quadrate, representing one of the top predators of their faunas. Historically, skull morphology is the most employed tool to investigate the relationships of baurusuchids, as most of the species have been primarily based on cranial remains. The present study describes a new baurusuchid species from the Bauru Basin of Brazil, based on the first tridimensional digital reconstruction of individualized skull bones for Notosuchia, and discusses its phylogenetic position within the group. The new species differs from all the other known baurusuchids by a depression on the posterior portion of the nasal bearing a crest, an infraorbital crest of the jugal that extends until the anterior margin of the lacrimal, the dorsal surface of the frontal lacking a longitudinal crest or depression, and the lateral convexity of the squamosal prongs participating in the occipital wall. The new taxon is consistently positioned as sister to the remaining baurusuchines, with Aplestosuchus sordidus and Stratiotosuchus maxhechti, as successive sister-taxa to a monophyletic Baurusuchus (Ba. albertoi, Ba. Salgadoensis, and Ba. pachecoi). Our updated phylogenetic analysis helps to differentiate the two major Baurusuchidae lineages, Baurusuchinae and Pissarrachampsinae. Yet, the new species shares morphological features with both groups, suggesting the occurrence of "Zones of Variability" in the radiation of Baurusuchidae.