Where does “antiopelmous” come from?

antiopelmous (English) comes from English -ous, from Middle English -ous, from Old French -us, from Latin -ōsus, from Old Latin -ōssus.

antiopelmous (English): Of birds: having a zygodactylous foot with one tendon to flex the third toe and another, trifurcate tendon to flex the first, second and fourth toes

Definitions

Of birds: having a zygodactylous foot with one tendon to flex the third toe and another, trifurcate tendon to flex the first, second and fourth toes

Ancestry of “antiopelmous”, step by step

Step	Language	Word	Meaning
1	English	-ous	Used to form adjectives from nouns, to denote...
2	Middle English	-ous	—
3	Old French	-us	-ous, used for forming adjectives
4	Latin	-ōsus	ose, -ous, -ful (full of or overly prone to)
5	Old Latin	-ōssus	—

Every word from Old Latin -ōssus →Every word from Latin -ōsus →Every word from English -ous →