Redescription of the Cranial Morphology of Mariliasuchus Amarali, and Its Phylogenetic Affinities (crocodyliformes, Notosuchia)

Abstract

The cranial morphology of Mariliasuchus amarali, a poorly known notosuchian from the Late Cretaceous of Southeastern Brazil, is redescribed based on new material. Its phylogenetic affinities within Crocodylomorpha are evaluated through a parsimony analysis involving 46 taxa and 198 characters. Mariliasuchus is nested well inside the clade Notosuchia, as the sister group of Comahuesuchus, a derived notosuchian from the Late Cretaceous of Argentina. Both taxa share the following unambiguous synapomorphies: ventral half of the lacrimal tapering posteroventrally, not contacting or only slightly contacting the jugal; presence of a large foramen on the lateral surface of the anterior part of the jugal; presence of procumbent premaxillary and anterior dentary alveoli; and ectopterygoids that do not participate of the palatine bar. The presence of procumbent premaxillary teeth, specialized tooth crown morphology, and fore-aft jaw movements suggests that this group presented complex jaw movements related to specialized feeding habits.

Mesozoic dinosaurs from Brazil and their biogeographic implications

“…Besides, no tetrapod taxon is endemic to the Bauru Group at a suprageneric level, and even genera such as Aeolosaurus, Peirosaurus, Roxochelys, plus baurusuchids closely related to Brazilian forms are recorded in Argentinean strata (Gasparini 1972, Broin 1991, Gasparini et al 1991, Riff and Kellner 2001, Franco-Rosas et al 2004). In addition, taxa recorded only in the Bauru Group are closely related to forms recorded in widespread localities across southern landmasses (Franco-Rosas et al 2004, Carvalho et al 2004, Turner and Calvo 2005, Zaher et al 2006, França and Langer 2006, Evans et al 2008. Although less diverse and abundant than some faunas of equivalent age in South America (e.g., Neuquina Basin, Novas 2009), the dinosaur assemblages of the Bauru Group is rather similar to the Late Cretaceous assemblages from other parts of Gondwana, especially Argentina.…”

“…Accordingly, the close relationship between the crocodyliforms from Itapecuru group with Gondwanan forms (i.e. notosuchians) (Zaher et al 2006, Kellner et al 2009), along with the occurrence of peirosaurids and baurusuchids in the Late Cretaceous, reinforces the existence of a vicariant pattern in crocodyliform distribution (Turner 2004). This scenario is also compatible with the distribution of dinosaurs in southern landmasses (Upchurch et al 2002, Novas 2007).…”

“…On the other hand, additional archosaurian records suggest a closer affinity of the northern fauna of the mid-Cretaceous of Brazil with African faunas (Medeiros andSchultz 2002, Novas 2009). This includes the spinosaurids from the Araripe Basin/Itapecuru Group, and the crocodyliform Candidodon itapecuruensis from the Itapecuru Group (Nobre 2004), which is closely related to the African Malawisuchus (Zaher et al 2006). This conundrum alternatively suggests a closer similarity between eastern and western Gondwanan faunas than previously thought.…”

A new species of Baurusuchus (Crocodyliformes, Mesoeucrocodylia) from the Upper Cretaceous of Brazil, with the first complete postcranial skeleton described for the family Baurusuchidae

“…In recent phylogenies, the family Baurusuchidae has been consistently found to be nested within Notosuchia (Ortega et al, 2000;Sereno et al, 2003;Pol, 2003;Pol & Norell, 2004;Pol & Apesteguia, 2005;Gasparini et al, 2005;Zaher et al, 2006;, a clade originally erected by Gasparini (1971) to accomodate the small-sized terrestrial fossil crocodyliforms from South America. The genera Cynodontosuchus, Stratiotosuchus, and Wargosuchus, commonly included in the family Baurusuchidae, share with Baurusuchus the following features: presence of theropodomorph teeth; reduction of tooth number; maxilla with a hypertrophied tooth; dentary with a hypertrophied tooth which fits in the premaxillamaxilla notch; maxillae verticalized; enlarged third premaxillary tooth overhanging the dentary; high mandibular symphysis (Gasparini, 1981, Campos et al, 2001.…”

"Descrição morfológica e posição filogenética de um anuro novo (Lissamphibia, Tetrapoda) do Cretáceo Superior Continental do Brasil (Formação Adamantina, Bacia Bauru) do Município de Marília, (SP)"

“…Os materiais atribuídos a este táxon estão representados por restos (Zaher et al, 2006). Os frontoparietais estão fusionados entre si, formando um osso único.…”