the dorsal vertebrae have spool-shaped centrae which are about 1.4 times longer than high, making them more elongated than those of herrerasaurids. several areas on the dorsals are incised, such as the sides of the centrum (which each have a shallow depression) and the rear of the neural arch (which has postzygapophyseal centrodiapophyseal and centrodiapophyseal fossae). there were likely three sacral vertebrae, with at least the first one articulating with the hip akin to the "primordial" first sacral of other reptiles. this contrasts with "saturnalia" in which the first sacral vertebra is an incorporated dorsal vertebra without the hallmarks of a primordial sacral. the sacral vertebrae were thick and wide, but not fused to each other or their respective sacral ribs. the most complete sacral rib was fan shaped when seen from above and has a cross section which gradually curves upwards towards the front, also unlike "saturnalia" which has a more l-shaped cross section. the caudal vertebrae increase in length and gradually reduce the size of their transverse processes from the base of the tail to the tip. caudals at the base of the tail have pronounced midline keels along their entire lower edge. this characteristic is seemingly unique to "nhandumirim", as the only other dinosauromorphs with ventral keels in proximal caudals are "dracoraptor" (which had paired, not midline, keels) and "efraasia" (in which they were restricted to the front third of the centrum). the zygapophyses of the caudals are short, unlike the longer joints of herrerasaurids and neotheropods.