Dental histology of three notosuchians (Crocodylomorpha) from the Bauru Group, Upper Cretaceous, South-eastern Brazil

Abstract

ABSTRACT The Upper Cretaceous Bauru Group deposits furnished several species of Crocodylomorpha, especially notosuchians. However, little is known about the feeding habits of this diverse group of crocodylomorphs. The dental histology is a destructive approach that can provide important information on tooth growth and feeding habits of fossil vertebrates. So far, few studies dealt with crocodylomorph dental histology and the ones available mainly focused on fossil and living neosuchians. In this work, we analyse the dental histology of three notosuchians commonly found in the Upper Cretaceous rocks of the Bauru Group: juvenile and adult Baurusuchidae, a large Sphagesauridae, and Mariliasuchus amarali. Our analyses indicate that tooth formation varied in these three taxa. In Mariliasuchus, a tooth took less than 2 months to be completely grown. On the other hand, in Sphagesauridae and Baurusuchidae, the tooth formation could take about 6 months to be completed. Mariliasuchus and Sphagesauridae have proportionally thicker enamel in comparison to Baurusuchidae. Additionally, the enamel thickness and its substantial development in the chewing area in Sphagesauridae indicate that apical advanced notosuchians are more adapted to process food items than more basal forms like Mariliasuchus.