Aphanosauria calcaneal tuber. Although this structure is smaller in aphanosaurs than in pseudosuchians, it is still much larger than in other avemetatarsalians, most of which don't even possess the structure. A few dinosauriformes also have small calcaneal tubers, although aphanosaurs have larger and rounder tubers than these taxa ("Marasuchus" and a few basal silesaurids). In cross-section, the calcaneal tubers of aphanosaurs are oval-shaped, taller than wide. Most foot material is fragmentary in this group, with only a few phalanges (toe bones) and metatarsals (primary elongated foot bones) known. Based on the length of the preserved metatarsals, the foot was likely rather
Roll the Bones strong vocal melodies at the beginning and base the rest of the tune around it. Lifeson had wanted to try playing funk rhythms and attempted it "Presto" and wished to explore it further on "Roll the Bones". The majority of the arrangements worked out at the writing stage remained unchanged which allowed the group to use the demos as a guide for recording, done by transferring the completed demos to 24-track and re-recording the parts. The album contains a running lyrical theme concerning the element of chance in different aspects of life, which Peart had devised while experimenting with lyrics.