Medieval parchments unlock a 3,500-year timeline of the sheeppox virus

A team sequenced sheeppox virus DNA preserved in parchment from medieval manuscripts in major libraries, recovering 21 ancient genomes dating from 1700 BCE to early modern Europe and showing the virus diverged from goatpox and lumpy skin disease 11,500–3,700 years ago. The work suggests parchments can preserve livestock pathogen DNA and that ancient outbreaks shaped European flocks, with some samples even from calfskin or goatskin indicating possible cross‑species infection or contamination.