Structure and Evolution of a Sauropod Tooth Battery

dinosaurs rose to predominance among vertebrate herbivores, in terms of both species diversity and biomass (e.g., Romer 1966; McIntosh 1990). Their perceived decline on northern landmasses during the Cretaceous has been linked to the evolution of tooth batteries in ornithischian herbivores (e.g., Lull and Wright 1942; Ostrom 1961; Bakker 1978; Lucas and Hunt 1989). On southern landmasses, in contrast, sauropod diversity increased during the Cretaceous (Weishampel 1990; Hunt et al. 1994), and a newly discovered southern sauropod, the rebbachisaurid Nigersaurus taqueti, is now known to have evolved a complex tooth battery (Sereno et al. 1999). Rebbachisaurids are a poorly known sauropod clade, reported thus far only from Cretaceous rocks in South America (Calvo and Salgado 1995; Bonaparte 1996; Apestiguía et al. 2001; Lamanna et al. 2001), Africa (Lavocat 1954; Taquet 1976; Sereno et al. 1999), and Europe (Dalla Vecchia 1998; Pereda-Suberbiola et al. 2003). Many of these are fragmentary finds, leaving much of the skeletal anatomy of this group in question, especially the skull. In this chapter, we describe the tooth-bearing bones and dental battery of Nigersaurus taqueti and provide an initial cranial reconstruction. We outline the feeding specializations common to diplodocoids and how these were modified within rebbachisaurids. Institutional Abbreviation: MNN, Musée National du Niger, Niamey.