Summary of pneumatic features of the theropod <i>Aerosteon riocoloradensis</i>.

<p>(A)-Silhouette reconstruction in left lateral view showing preserved bones of the holotype and referred specimens (MCNA-PV-3137-3139); body length approximately 9-10 m. (B)-Left quadrate in posterior view. (C)-Dorsal 14 in left lateral view with enlarged cross-sections of the neural spine and transverse process. (D)-Furcula in anterior view with sagittal cross-section. (E)-Cross-section of medial gastral element from the anterior end of the cuirass showing pneumatocoel. (F)-Left ilium in lateral view with enlarged cross-section of pubic peduncle. Scale bars equal 5 cm in B, 10 cm (3 cm for cross-sections) in C, 10 cm (same for cross-section) in D, 2 cm in E, and 20 cm (6 cm for cross-section) in F. <i>Abbreviations: aqj</i>, articular surface for the quadratojugal; <i>asq</i>, articular surface for the squamosal; <i>bfo</i>, brevis fossa; <i>ca</i>, canal; <i>dipc</i>, diapophyseal canal; <i>ep</i>, epicleideum; <i>hpo</i>, hyposphene; <i>ilb</i>, iliac blade; <i>isped</i>, ischial peduncle; <i>ns</i>, neural spine; <i>pa</i>, parapophysis; <i>pc</i>, pleurocoel; <i>pnec</i>, pneumatocoel; <i>pned</i>, pneumatic depression; <i>pnep</i>, pneumatopore; <i>poap</i>, postacetabular process; <i>poz</i>, postzygapophysis; <i>pped</i>, pubic peduncle; <i>prap</i>, preacetabular process; <i>prz</i>, prezygapophysis; <i>ptfl</i>, pterygoid flange; <i>qc</i>, quadrate condyles; <i>qf</i>, quadrate foramen; <i>qh</i>, quadrate head; <i>se</i>, septum; <i>tp</i>, transverse process.