Fig. 12. A in The early evolution of postcranial skeletal pneumaticity in sauropodomorph dinosaurs

Fig. 12. A phylogenetic diagram showing the distribution of invasive PSP along the vertebral column (the caudal series is truncated) in Sauropodomorpha. Black boxes indicate the presence of pneumatic fossae or invasive infradiapophyseal subfossae. Note that in the case of Plateosaurus PSP is presently known in a single specimen whereas other specimens of same taxon lack it. The phylogeny is based on Yates (2010), with the modification that Eucnemesaurus is placed closer to Anchisauria than Massospondylus is. The position of the Spion Kop sauropod is based on an unpublished analysis (AMY unpublished data). The distributions of PSP in the taxa not directly examined in this study were gleaned from the following sources: Pantydraco (Yates 2003; Wedel 2007), Tazoudasaurus (Allain and Aquesbi 2008), Shunosaurus (Zhang 1988), Jobaria (Sereno et al. 1999), Haplocanthosaurus (Hatcher 1903).