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
Ostromia addition, the ungual (claw) of the first digit of the hand is smaller than the corresponding first metacarpal, while in "Archaeopteryx" the claw is larger. The Haarlem specimen's metatarsals are also estimated to be proportionally longer than those of "Archaeopteryx" specimens. In addition, the Haarlem specimen shares several features with "Anchiornis". Most notably, they both have longitudinal furrows on the top and bottom sides of their manual phalanges (finger bones). While such structures can be a result of collapsed or broken bones (as is the case in several "Archaeopteryx" specimens), the straight, smooth edges of the furrows in "Ostromia" and