1. The ordinal number of thirty-six in counting order
   - thirty-sixth

See also: ordinal

• family Antilocapridae
• family Aphididae
• family Aphyllanthaceae
• family Apiaceae
• family Apidae
• family Aplodontiidae
• family Aplysiidae
• family Apocynaceae
• family Apodidae
• family Apogonidae
• family Apterygidae
• family Aquifoliaceae
• family Araceae
• family Araliaceae
• family Araucariaceae
• family Arcellidae
• family Arcidae
• family Arctiidae
• family Ardeidae
• family Arecaceae
• family Argasidae
• family Argentinidae
• family Argiopidae
• family Argonautidae
• family Ariidae