A new Late Cretaceous Rhabdodontid dinosaur from Southern France

Extreme tooth enlargement in a new Late Cretaceous rhabdodontid dinosaur from Southern France
Right maxilla of Matheronodon provincialis gen. et sp. nov. (MMS/VBN-02–102; holotype) in dorsal (a), lateral (b), medial (c), and ventral (d) views. (e) Close-up of the second and third maxillary crowns.

Rhabdodontidae is a successful clade of ornithopod dinosaurs, characteristic of Late Cretaceous continental faunas in Europe.

A new rhabdodontid from the late Campanian, of southern France, Matheronodon provincialis gen. et sp. nov., is characterized by the extreme enlargement of both its maxillary and dentary teeth, correlated to a drastic reduction in the number of maxillary teeth (4 per generation in MMS/VBN-02-102).

The interalveolar septa on the maxilla are alternately present or resorbed ventrally so as to be able to lodge such enlarged teeth. The rhabdodontid dentition and masticatory apparatus were adapted for producing a strict and powerful shearing action, resembling a pair of scissors. With their relatively simple dentition, contrasting with the sophisticated dental batteries in contemporary hadrosaurids, Matheronodon and other rhabdodontids are tentatively interpreted as specialized consumers of tough plant parts rich in sclerenchyma fibers, such as Sabalites and Pandanites.

Rhabdodontids are basal iguanodontian dinosaurs and characteristic elements of Late Cretaceous dinosaur faunas in Europe. They have also been described in Early Cretaceous deposits of Spain. Rhabdodontids are commonly represented, in late Campanian-early Maastrichtian dinosaur faunas of southern France, by two species of the genus Rhabdodon: R. priscus and R. septimanicus.

Rhabdodontid disarticulated elements have recently been discovered at Velaux-La Bastide Neuve, Bouches-du-Rhône Department, southern France. This locality has yielded an abundant and diversified vertebrate fauna, including the titanosaurid sauropod Atsinganosaurus velauciensis, ankylosaurian remains, theropod teeth, an ontogenetic series of cranial and postcranial elements of the basal eusuchian crocodile Allodaposuchus precedens, pleurodiran and cryptodiran turtles, pterosaurs, hybodont shark teeth, and mawsoniid bones. Here we describe a new rhabdodontid dinosaur, Matheronodon provincialis, from Velaux-La Bastide Neuve, with a quite unusual dentition.

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Extreme tooth enlargement in a new Late Cretaceous rhabdodontid dinosaur from Southern France. DOI:10.1038/s41598-017-13160-2