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
Anatomical terms of bone Anatomical terms of bone Many anatomical terms descriptive of bone are defined in anatomical terminology, and are often derived from Greek and Latin. A long bone is one that is cylindrical in shape, being longer than it is wide. However, the term describes the shape of a bone, not its size, which is relative. Long bones are found in the arms (humerus, ulna, radius) and legs (femur, tibia, fibula), as well as in the fingers (metacarpals, phalanges) and toes (metatarsals, phalanges). Long bones function as levers; they move when muscles contract. They are responsible for the body's height. A short