Table 2.
Homologies of the avian intrinsic manual musculature with crocodylians, lepidosaurs, and testudines.
| Aves (Baumel et al. 1993) | Crocodylia (Meers, 2003) | Lepidosauria (Russell & Bauer, 2008) | Testudines (Walker, 1973) |
|---|---|---|---|
| Extensor longus digiti majorus pars proximalis | Extensor digitorum superficialis, digit II | Extensor digitorum brevis superficialis, digit II | Extensor digitorum brevis (part), digit II |
| Ulnimetacarpalis dorsalis | Extensor digitorum superficialis, digits III and/or IV | Extensor digitorum brevis superficialis, digits III and/or IV | Extensor digitorum brevis (part), digits III and/or IV |
| Extensor brevis alulae | Extensor digitorum profundus, digit I | Extensor digitorum brevis profundus, digit I | Extensor digitorum brevis (part), digit I |
| Extensor longus digiti majorus pars distalis | Extensor digitorum profundus, digit II | Extensor digitorum brevis profundus, digit II | Extensor digitorum brevis (part), digit II |
| Flexor alulae | Flexor digitorum brevis superificalis, digit I | Flexor digitorum brevis, digit I | Flexor brevis superficialis, digit I |
| Adductor alulae | Flexor digitorum brevis profundus, digit I | Lumbricals (part), digit I | Flexor brevis profundus, digit I |
| Abductor digiti majoris | Flexor digitorum brevis profundus, digit II | Lumbricals (part), digit II | Flexor brevis profundus, digit II |
| Flexor digiti minoris | Flexor digitorum brevis profundus, digit III | Lumbricals (part), digit III | Flexor brevis profundus, digit III |
| Abductor alulae | Abductor metacarpi I | Flexor digitorum brevis, digit I deep part | Abductor pollicis brevis |
| ‘Abductor digiti minimi’ (only present in Struthio) | Abductor metacarpi V | Abductor digiti quinti | Abductor digiti minimi |