heterodactyl
/ˌhɛtərəˈdæktɪl/
adjective
- Having toes arranged in a specific pattern, with the first and second toes pointing backward and the third and fourth pointing forward (as in trogons).
- Unlike most birds, heterodactyl species have a reversed first toe.
- The trogon's heterodactyl foot helps it grip branches tightly.
- Ornithologists use the term heterodactyl to describe this unique toe arrangement.