Paleohistology of the crocodyliform Mariliasuchus amarali Carvalho & Bertini, 1999 (Mesoeucrocodylia, Notosuchia) based on a new specimen from the Upper Cretaceous of Brazil

Abstract

Mariliasuchus amarali Carvalho & Bertini, 1999 was a terrestrial quadruped crocodyliform from the Late Cretaceous of the Bauru Group, Brazil. In this paper we present the first study of the bone histology of this species. Moderate growth rate, interspersed by growth marks, was observed in thin sections of a rib and appendicular bones; growth patterns observed in M. amaralis appear similar to those observed in Triassic archosauriforms. The M. amarali cross-sections indicate growth variability between both the axial and appendicular bones. Distinctive remodeling processes were found in the radius, which had extensive inner cortex remodeling composed of compacted coarse cancellous bone. Furthermore, the medullary region was infilled with spongy bone.