proavian
/ˈproʊ.ə.vɪ.ən/Definitions
1. noun
A hypothetical ancestor of the birds, or a hypothetical early bird.
“The discovery of a proavian fossil helped scientists understand the evolution of birds.”
2. noun
A person who promotes or advocates for avian-related causes or interests.
“He was a passionate proavian, working tirelessly to protect bird habitats.”