Montealtosuchus arrudacamposi, Carvalho, Ismar De Souza, Vasconcellos, Felipe Mesquita De & Tavares, Sandra Apare- Cida Simionato, 2007

Carvalho, Ismar De Souza, Vasconcellos, Felipe Mesquita De & Tavares, Sandra Apare- Cida Simionato, 2007, Montealtosuchus arrudacamposi, a new peirosaurid crocodile (Mesoeucrocodylia) from the Late Cretaceous Adamantina Formation of Brazil, Zootaxa 1607, pp. 35-46 : 38

Montealtosuchus arrudacamposi gen. nov. et sp. nov.

(Plate 1, 2)

Etymology: The species name, arrudacamposi , is in honor of Antonio Celso de Arruda Campos, eminent Brazilian paleontologist and professor.

Holotype: MPMA-16-0007-04 (Museu de Paleontologia de Monte de Alto). Skull, mandible and almost complete axial and appendicular skeleton, and articulated dorsal and ventral exoskeleton (osteoderms).

Locality: 14 km of Monte Alto, near the border between Monte Alto and Taiaçu counties, São Paulo State, Southeast of Brazil.

Stratigraphic context: Bauru Basin, Adamantina Formation, Upper Cretaceous (Turonian-Santonian).

PLATE 1. Holotype of Montealtosuchus arrudacamposi gen. nov. et sp. nov. (MPMA-16-0007-04) in 1 dorsal view of skull and mandible; 2 lateral view of the skull; 3 lateral view of mandible; 4 palatal view; 5 dorsal view of mandible; 6 occipital view.

Diagnosis (skull): Snout moderately narrow, tubular in cross-section. Skull triangular in dorsal view. Anterior nasal process at the tip of snout, hanging over the external naris. Continuously sloping surface connecting the rostrum and skull table. A small slit-shaped notch for the 4th mandibular tooth at the contact between maxilla and premaxilla. Five premaxillary conical teeth progressively increase in size posteriorly, all evenly spaced. Wedge-like maxillary process of the premaxilla present. Foramen incisivum with maxillary marginal contribution. Fourteen maxillary teeth in sinuous outline, with moderate heterodonty, displaying anterior sharp conical teeth and posterior low, laterally compressed globular teeth. Anterolateral external nares in vertical position. Nasals participating in a non-septate external nares. Orbits subsquare. Antorbital fenestrae present. Two triangular supraorbitals bordering dorsally the orbit. Postorbital bar ascending from the mesial border of the jugal. Supratemporal fenestrae elliptical, smaller than orbits, and set in a non-sculptured depression, bordered by the parietal, postorbital, squamosal and small contribution of the frontal. Supratemporal with minimal participation in skull table. Quadratojugal participates with the quadrate in skull-mandible articulation. Deep, square choanae, evenly composed by palatines and pterygoids. Palatine fenestrae elliptical, bordered by maxillae, palatines, ectopterygoids and pterygoids. Basioccipitals inclined toward the palatal surface. Exoccipitals wide and bend anteriorly and half of its height. Eustachian foramina closely disposed in “v” pattern, in the palatal view. Splenials participating in 1/3 of the symphysis. Symphysis extending to the 10th tooth. Mandible arched upward at anterior and posterior ends. Articular presents deep concave articular surface, with contribution from the surangular. Retroarticular process paddle-shaped and inclined dorsally and mesially. Mandibular fenestrae elliptical, aligned with the laterotemporal fenestrae. Eighteen dentary teeth show two morphotypes: anterior ones conical and sharp, with hypertrophied 4th tooth; posterior teeth globular, low, and laterally compressed. All premaxillary, except the first, maxillary and dentary teeth bear constricted basal crown and fine serrated carinae.