Lineage Registry: an ERC-721 extension for on-chain genealogical trees

Henrique L. Alvim proposed 'Lineage Registry,' an ERC-721 extension standard for decentralized genealogical tree registration, aimed at replacing private, trust-based studbooks with an on-chain directed acyclic graph for verifying animal pedigree. Each token carries a sex and birth date and is either a founder or descends from exactly one sire and one dam, with six mandatory rules (sexed parentage, all-or-nothing parentage, pre-existing parents, write-once records, chronology, and owner consent) plus four opt-in extensions behind ERC-165. Acyclicity is enforced for free via monotonic token IDs, a reference implementation is deployed on Base Sepolia, and the author lists eight open questions on design choices such as sex representation, placeholder nodes, duplicate merging, and cross-registry linking.